I finished wrapping up the internals of the radio. I had needed to build a standoff for the Bluetooth board and went looking for something suitable to make some legs from. I ended up going to the hardware store, where a bit of innovation led to the purchase of 4 nylon pipe joiners and some screws that fit into them well, with a coarse thread.
I drilled some holes in the case and mounted the board in place (bottom right). I wired it in and tested it, successful connection from across the room even with the case fully assembled. I’m guessing the high frequency Bluetooth radio can traverse the cooling holes. If not, I was going to get an external antenna for it.
I went and test-fitted the radio to the car (not an easy task, a few things need to be undone and moved aside for it to fit) which works nicely. I peaked the input cap to the antenna (which goes up and down when the radio is switched on and off) and tested the Bluetooth.
Small blip in the editing was just me cutting 6 seconds of awkward silence as my old phone decided to be slow to pair to the Bluetooth in the radio. I’m still tempted to add a little something else to it. We’ll see. I need to change the buffer capacitor on the rectifier before it sees any serious use but overall, that’s done and ready to go.
I turned my attention to the remainder of the chassis once the power supply and volume control were built. I took a permanent marker and wrote the part identifier from the schematic plus its capacitance value where it was illegible or facing the wrong way.
I decided to replace every component. I’m glad I did, because easily half of the resistors were wildly incorrect in value and I’m sure all the old paper/wax capacitors were equally bad. I pushed the tubes in and powered up gingerly. After wiggling one tube a bit to clean the contacts I was greeted with AM static.
It was nice to see the thing fully populated with tubes again, and assembled. I cleaned it up a bit (it was rather dusty) and put the face back together.
It’s far from perfect, but I think it looks okay. I might paint it in the original silver to match the back of the case.
I had done a bit of research into Bluetooth modules, and found a nice one that has an audio pass-through using a mechanical relay. When nothing is connected, the relay is connected in such a way that the audio in passes through to the output connector. With a Bluetooth device paired, it engages and disconnects the input audio and sends its’ own generated audio out. Ideal, as the radio can function as original until a Bluetooth device is connected, then it’ll feed through from that. I had started work on this as you can see; the connectors de-soldered from the board and a rather large ferrite core inductance choke connected to the power input. There was quite a lot of hash being picked up and send back into the radio and out the loudspeaker through the heater circuit. I added that choke and a couple of high value capacitors to the heater chain which silenced the noise. I replaced the audio wire that goes to and from the volume control because the original had a short circuit break somewhere inside, and had the out and back signals twisted together, inside a shield. When it was just an AM radio this was perfectly acceptable but when the Bluetooth module engages, the amount of cross-talk from the radio circuit made the end result unintelligible. I separated the radio output and volume control mix return wires in their own shielded, individual wires. That resolved 99% of the interference issues and made the audio output very clean.
I set the radio on the side and streamed music to it for several hours. The quality of the audio is impressively good; the design of the power amplifier circuit is good and while not quite a full 12 Watts due to a lower plate voltage than usual (at a guess it’s about 8 Watts) it is a good, hi-fi design, and with a full-range loudspeaker the sound it produces far surpasses any expectations of the device. Last to-smile-at feature will be in the car, installed. With my phone connected, it represents a hands-free calling system… not a bad option for 1951!
When I bought my Chieftain, the original radio was long-since gone, replaced with a more modern stereo cassette-player. The new one was designed to look a little “retro”, but really was better suited to a mid 1970’s vehicle than one from the 1950’s. At a guess, when the vehicle was converted to 12 Volt the converter either realized that the radio was incompatible, and required a converter to operate at 12V or they powered it up and it let all the magic smoke out very, very rapidly…
What happened is mere speculation- I’m guessing the former because there are no marks up inside the dash to indicate there was any electrical fire. More likely an upgrade was decided upon.
So, that was pulled out pretty quickly because it was horrible. I had a bit of a thought and went took a look at the radio sets used in these cars and similar cars of the era. I put a bid in on a radio with the correct knobs to match the rest of the dash and won it. It had been stored damp, and the tuner assembly had suffered zinc pest, a crystalline breakdown of the zinc due to lead impurities and moisture. Undeterred, I did my due diligence and determined that the 1956 Buick “Sonomatic” radio held enough in common with the 1951 Pontiac set that it could be used to supply parts to repair the broken tuner assembly and also liberate the all-important high-voltage transformer to convert the set natively to 12V operation.
Way back last year I made a start on the set then shelved it following a trip out of state, where I got distracted by the Zenith radio in the previous post. Having completed the Zenith, I was able to clear my bench…
…which was promptly filled up with Delco radio. I took a look at it and tried to figure out exactly what I had done some 14 months earlier. Having pulled the Riders schematic up for both the Pontiac and Buick radios, I set about re-familiarizing myself with both the schematic, the chassis and the work I had done and then stopped.
I took a look at the socket for the vibrator that I had made a repair to previously. I saw that the center lug needs to be connected to chassis, so I bent the tang down and… snap. The thing broke off where the brass had work-hardened. So, I split the two pieces of phenolic apart and began work on a solution.
I hammered a fork connector flat, bent it up in profile to meet up with the socket. I then took my propane torch and soldered it to the chassis- at this point I could use high heat because there was no phenolic in place. After it had cooled and made a very strong connection, I slid the phenolic in under it, with the lug in place, which was then soldered with a less intense heat from my iron so as not to char the insulator.
The rest of it then screwed in place. While not as strong as it was originally (and missing two brass rivets), supporting the back while inserting the vibrator is adequate to prevent it from breaking further. On the other side there is a heavy 6-fingered spring holding the vibrator secure so there is very little mechanical load on the pins.
I then went on a spending spree and bought the 12V equivalents of the original tubes (sadly the Buick set used 12V6 output tubes and had no others in common- but the Pontiac set used 7C4 output tubes, which are 6V6 with a Loctal base), along with a full compliment of new capacitors.
While I was waiting for the parts to arrive, I got bored with the old ones and utilizing a bag of googly eyes I have in the drawer of my desk created The Analog Gang, the meanest bunch this side of the B+ rail…
The first thing I decided to tackle was the power supply. I wired the vibrator and the power transformer up, connected an old 9V battery to it and the output pegged my meter set on 1500VAC range. Safe to say, unregulated, the power transformer was still good. Once the capacitors arrived I decided to tackle the 3-in-1 HT rail capacitor. Originally the can was stuffed full of a big wad of foil and paper, comprising 3 independent, common cathode capacitors. One 10uF, one 15uF both at 400V and a 20uF 25V one. This had all gone bad with age, so the can was sawn open, gutted, cleaned up and the base drilled out to give access for new wires to be threaded through.
I bought short but fat capacitors, high temperature, 450V. Because there is the possibility of a solid-state vibrator in this set’s future, I needed to add more filtering to the B+ high voltage lines as the SS devices create more hum than the original mechanical ones. So, I used 2x 40uF B+ capacitors with a 20uF cathode filter.
The can was all polished up. Being aluminum it came up looking pretty. The values stamped into it are wrong but the connectors do lead to the correct part. With the back off the inside of the radio looks a little more original.
I finished up the HT supply. I will need to change the resistor and the cap marked TOPMAY because the value of them are too low- the resistor is meant to be a 2 Watt item (that’s a 1/2 Watt) and the buffer capacitor should be 0.007uF, not the 0.005uF that’s in there. As the value is quite critical I have been advised that 0.0068uF is closer and should be substituted.
In the picture above this one you can see that there is quite a lot of wax on one of the socket pins on the right-hand side. This is from the old buffer capacitor, which had failed quite spectacularly and sent liquid wax all over the inside of the HT supply case. I shredded the top of a Q-Tip onto a small jeweler’s screwdriver, dosed it with isopropyl alcohol and used that to clean the wax out of the connector.
With that thoroughly cleaned and the socket bent back into shape, I was able to give a test of the HT supply properly, with the rectifier in place.
Using a half-dead 9V square battery, I was able to bring up 90VDC on the high voltage side of the power supply. This was immediately considered a success.
Out of curiosity, I removed the metal lid off one of the 0Z4 rectifier tubes I have and powered it up. It glows quite spectacularly! It is a cold-cathode device, rather like a neon sign tube, except there is an anode connection and two cathodes. As the voltage rises on one, it reaches a critical threshold where the argon gas inside ionizes and begins to conduct- releasing the bright mauve glow. This is encapsulated in a metal shield to try and reduce RF emission.
With the power supply operational, I started on the next loose piece. I had removed the volume and tone control previously, so figured it would be a good place to continue. It’s a triple stacked item, with a power switch operated by the volume control, the volume potentiometer and a 4-position switch for tone control.
I cleaned it up, removed the old components and replaced them with new. I’m glad I did because the resistors had all drifted well out of spec (2 were more than 50+ more resistance than they were marked for). In working out how it was all assembled and operated, I determined one thing that made me smile- the set has rudimentary loudness compensation. At low volume, the bass and treble are boosted, with the mid tones reduced. As the volume is dialed up it reaches a transition point on the track where it is tapped (25/75% of the sweep) where a different capacitance takes over the tone control and allows full treble. Simple, but effective. With that complete, I moved on to rebuilding the main chassis.
A while back now I took on a project for a friend. A 1933/34 Zenith “Glove-box” automotive radio.
This is the first picture I took of it- not a very good one but you can see that it was rusty, missing the knobs and generally full of old dead spiders and dust.
I stripped the radio down. The lower half of the chassis is at a 45-degree angle and houses the speaker and power socket. That was removed so it would sit flat. I pulled the dial bezel and glass aside to safety as the glass was unbroken and in good condition. The dial face was equally in good shape so was removed and stored safely after a gentle cleaning.
I repainted the bucket the dial sits in and finished the face.
I tested all the wound components and they were good. That was good because they’re the hardest parts to source and replace if they are bad.
I cleaned up the screws. In the image, the one on the right looked like the one on the left to begin. The set has some nice panel-headed screws that hold the chassis in the frame that are prominent on the front and sides. So, I spun them against a file and de-burred the surfaces, polished and nickel-plated them.
I started to clean the power supply chassis up. The capacitors were past their prime when the set was in operation and the mess there is a mixture of wax, capacitor dielectric paste and dirt- the set was also home to quite a few spiders, all of which were petrified and crispy. The failure there where the main smoothing capacitor had vented was also likely the reason for the set being removed. that would have caused the fuse to blow every time it was switched on.
The power chassis cleaned up well enough to continue. There are a lot of high voltage parts in this section, all of which tested bad. It also runs quite warm, being encased in a metal box with no ventilation- to prevent RF noise.
The volume control also tested bad. the schematic showed it to be 1 MegOhm from end to end but it had dropped in value (odd behavior, usually they go up) which meant that the set would never be adjustable to quiet, it would start at loud and get louder. I had never seen a potentiometer like this before- a good design in theory. Normally in a carbon track device there is a phenolic wafer with a carbon trace printed on it, and a metal finger that touches the carbon as the center tap. As you dial it round, the finger slides across the carbon. Eventually the track wears out and the potentiometer becomes noisy and unreliable. This one had a carbon track and a spring-steel ribbon that was slightly smaller than the inner track. A finger pressed the ribbon against the track, making the contact and the only friction was of the finger against the spring steel, which would last a very very long time. As the ribbon was only pressed against the carbon and not dragged, it would also last. I think the carbon track, printed on cardboard, had become damp and deteriorated that way. so, I replaced the volume control and power switch with a new one, modified to suit.
I replaced all the old paper and wax capacitors and after more than half of the old resistors tested bad (most had either gone open circuit or had drifted very high resistance) I replaced them all with high stability metal film 1% devices.
I managed to get the old mechanical vibrator apart, clean the contacts and get the high voltage to come up operational. First test was positive, nothing smoked up and I was able to just about get a local radio station to come out of the speaker, proving all stages of the radio were at least operational. The vibrator, which interrupts the input to the power transformer providing a rudimentary AC, was very loud, almost intolerably so. So, I purchased a solid state one which is very efficient and mostly quiet, changed the socket for a new porcelain one (the old one had 6 pins, this one a more standard 4) .
With the electrical portion of the radio working as expected, I set about tidying up the cosmetic parts of the case. The face was rusty, so I took to it with my DA sander and removed the pitting and rust.
I left the smaller dents because they are part of the original character- there were a couple bigger dinks that I knocked out. All down to bare metal, it was time to prime and paint.
The original paint finish was wrinkle-black. I bought some of this horrible finnicky paint and redid the front in it. First revision above, part of it bubbled (it has to be heated) and the rest went psycho-insane and wrinkled up like craters on the Moon. Second revision went much better and has the correct finish.
I then redid the rest of the case (three attempts for the main case, another three for the lid).
I cleaned all the rust off the dial beauty ring, polished it and clear-coated it.
I was able to carefully remove a very fragile remnant of grille cloth from where it was attached to the metal behind the grille aperture. I washed it and the pattern became visible- most of the cloth had rotted and was just threads. I found a company in Shreveport, LA who was re-manufacturing original Zenith grille cloths, so bought a length. A very rich color, in shiny thread as per the original.
The grille cloth, glued to the freshly painted case. Looks most excellent.
I got the Dremel out again, removed the rust from the clip, polished and nickel plated the clips that hold the lid on.
I bought some nice yellow cotton covered cloth to fit and replace the very dry, crispy original wires that led to the tube top caps. This keeps the nice period look but gives new wire. All re-aligned for its’ home in the case, picking up a bunch of local stations during the day.
A couple of new original-style knobs finished the radio off, and an auxiliary-in socket for when the AM radio has nothing to offer.
I finished up the workshop by replacing the original light fixture with a newer one. I still want to fit more lights but a couple of 40W tubes work for now. Better than having to fight flipping the light switch repeatedly to get the room to illuminate.
I bought a new set of points to fit in the distributor. The old set was a bit pitted (which did clean up) but the fulcrum was worn and the points would not align very well by themselves. I’d been seeing some misfire at higher engine RPM so figured it was worth a shot at replacing the points. It didn’t help much but it did at least eliminate that as being the cause.
Having been parked up int he garage for a while, the wipers stopped working. I took the motor apart and tried soaking the rubber seals in mineral oil to try make them swell up a little, but this was to no avail. It really just needs to be rebuilt. There is a firm in NY state that’s doing Trico wiper motor rebuilds so they’re on the to-call list.
After the wipers, the car went on a little hiatus. I decided to finally do a little work on the car and adjust up the driver’s side brake because it would snatch and lock the wheel if the brakes were pressed moderately hard, instead of braking progressively. This is a sign of badly adjusted or contaminated brake shoes in drum brakes. I jacked the car up, pulled the wheel off and took the bearing race to pieces.
With the outer bearings removed and cleaned I took a look at the brake shoes. They were greasy from where the bearings had been over-packed, which is never a good thing. The shoes also showed signs of having over-heated and the lining on the leading shoe is beginning to fall apart.
Given that, I turned my attention to the drum, which was in good shape, albeit very greasy.
I traded a six-pack of beer for an old, beaten up aluminum pot from my neighbor, which I beat back into shape with a lump hammer.
I put the brake drum into the pot, filled it with dish soapy water and boiled it a few times to remove the grease. This proved most effective.
I beat the bearing dust cap back into shape and painted the lot to stop it from flash rusting.
I had tried the brakes with the drum removed and saw that only the rear shoe was being operated. I held the rear shoe and prevented it from moving and applied force to the pedal, which freed up the front piston. The wheel cylinder then began to leak badly from the newly moving piston. No good! Time for new hydraulics.
I made a little warning light panel to fit under the dash. The alternator has provision for a no-charge light (an accompaniment to the ammeter) and someone had fitted an oil pressure switch to the main oil gallery (in accompaniment to the oil pressure gauge).
I borrowed a set of letter punches and used them to press an impression of letters into the plastic of the light lenses.
I decided on era-appropriate descriptions- GEN (for GENerator) and OIL. I dabbed a bit of black paint into the recessed letters.
After purchasing some correct Wattage bulbs, both lights function as expected. The OIL I decided to be orange because it is bright and that one I am much more concerned about. the oil pressure gauge is heavily damped, so doesn’t give a quick reading, the light comes on immediately below 5 PSI. The GEN light flickers and comes on at low RPM which is normal for this engine. I would need a smaller pulley to prevent that from happening, but it charges well over 800RPM.
Turning back to other issues with the car, I went on the look for a replacement distributor or vacuum advance plate. Someone turned up a new-old-stock dual points conversion kit, which I bought. This solved a few problems, primarily the lateral wobble in the old plate because it was bent and worn. Second, it extends the life of the points and decreases the need for routine inspection, cleaning and gapping. Third, it has an added benefit of extended dwell which allows the coil to saturate fully at high RPM (admittedly much higher RPM than my engine can achieve but the principle is sound).
I took the distributor out and dismantled it.
Being as it was out, I cleaned the rust off and painted the body.
I fitted a new condenser to the set and reassembled it with the dual points plate in, which moves very smoothly compared to the old one and also keeps the points in the correct plane with respect to the cam.
Continuing with the ignition system, I removed the spark wire manifold, which was missing a part and also was all dented and dirty.
I hammered the sheet metal back into shape. I turned my attention to the lead-out tube which was missing the lower half (the curved section).
I bent, hammered and shrunk the metal into shape.
I painted it all up and fitted a new set of spark plug leads.
I gave a test-fit and that showed a significant improvement over the old set of leads; 4 new spark plugs of the 8 that I had ordered arrived, so I fitted them, switched out a couple of the older plugs and managed to get the engine running on 8 cylinders again. I need to tidy up a little bit but that’s progress, at least.
Back to cosmetics, the horn push had always been a sore point for me- the center of the emblem should be bright red, but with sun and time it had faded to a pale brown. I managed to take the thing apart by carefully bending the lip of the chrome surround ring up.
I cleaned the old lacquer off, masked up and painted new red lacquer with the remnants of the red in the can I used for the rest of the badges on the car.
I polished the clear cover as best as I could and reassembled it. A significant improvement, especially considering it’s right in front of you when you sit in the driver’s seat. Shortly after that, a mysterious benefactor sent another one that was in very good condition, with almost no crazing to the lens, which was very kind.
finally, I took the time to rebuild the cable and latch for the slam panel. All reassembled, the hood finally closes correctly and can be pulled open from inside the car.
So, a new year and new things to do on the car. After having done a little work to clean some of the paint I decided to try mix up a color match for the 1957 Ford blue that is on the car.
The first attempt was not too far off but didn’t look right- the blue dried a lot darker than it mixed up. I tried again.
The second attempt came out a much closer match. Acceptably good, I touched up a few more of the spots where the paint had been knocked off, to try and protect it a little.
I touched up the back of the car to tidy it up a little. It all needs cutting out and new metal letting in but that’s a little ways off happening yet. It makes the car look better from ten feet away, at least.
I also made an attempt to flatten out the faces of the intake/inlet manifold, as it was not sitting well enough in all places to seal. Apparently common with long manifolds like this, it has warped with age and heat/cool cycles. I managed to get all but the center two exhaust ports flat enough to sit into the gasket; really it needs to be put on a milling machine and be milled down like the deck of an engine block. For now it is good enough that I can double-gasket the center two ports to get them to seal.
A little bit of pleasant weather allowed me to bring the car outside and start smartening the paint up. The roof has lost a lot of the clear lacquer, and I was trying to figure if I had wanted to polish the paint or not. If I were to polish it, re-applying clear lacquer would be difficult without almost completely stripping the paint back. In the end I decided to polish it up to seal it and protect what color is left. The mid-blue on the rest of the body responded well to wet-flatting and polish.
The roof has a nice gloss to it when finished well. I just need to carefully blend in the edges of the remaining clear coat.
The rear light lenses on this car are unique to the year- they are very bulbous compared to the preceding and following years, and are slightly smaller so the more common 1952 lenses, popular with hot-rodders are available easily and cheaply but these are not. The sun had done a number on these so I decided to try sanding one down and giving it a few coats of red lacquer to try and get a little more life out of it. the result is not perfect but looks much better than it did. I am also considering finding some reflectors to put inside because they are quite dim, even with LED’s inside.
I soldered in the brass overflow tube to the radiator and polished the radiator cap up. I do need to replace the cap as it is the wrong pressure (4lb instead of 7lb) but in the interim it looks better.
I took the front right brake to pieces because it was not really providing much int he way of braking effort and was quite snatchy. The lower adjuster was fairly easy to free up but the top one which has a large nut to hold it in place was stuck fast. I ended up having to borrow a larger socket from a neighbor and with most of my weight on a 5 foot extension bar finally managed to get it to free off.
Only a small portion of the threads had gone rusty but that, coupled with it having been done up by a gorilla, had meant it took upward of 2500lb/ft to undo. I cleaned it up and refitted it.
Armed with a copy of the manual pages pertaining to the brakes, I checked the shoes were free to move, both brake pistons were free to operate and then set the clearances and adjusted the shoes.
A few things arrived in the mail. first, someone sent me a gift of a replacement dome light cover as mine was long gone. This is a Chevrolet item but is not dissimilar to the Pontiac one and fits the same light assembly.
More goodies, in the form of a new “diode trio” for the alternator- the purpose of which is to feed half-wave rectified DC into the voltage regulator circuit to allow it to boost or drop the armature winding on the rotor and thus increase or decrease the output of the alternator.
Apart came the alternator again. Buried down in the depths is the offending article.
The diode trio was replaced (orange and black pieces, black being the new one) and the alternator reassembled. This provided a good output- I wired it temporarily to the ignition switch to get it to make the ammeter move. What I didn’t think about was how it was actually wired in; when I switched off the ignition the alternator was disconnected from the battery and no longer had a regulated reference so went into a free-running wobble which fried the 12-to-6 volt converter unit for the fuel gauge.
The car had also developed a bad misfire once it warmed up a little, resulting in clicking valve followers. I decided to pull the head off and soak the valve stems in Marvel Mystery Oil (which is essentially just mineral oil) to see if they would free up.
The oil was unsuccessful in freeing the valves up adequately- with the engine cold they would work perfectly for about 15 seconds before getting stuck open. In the interim I had ordered a replacement DC-DC converter for the fuel gauge which thankfully got it working again. I prefer it to have taken that out rather than burn the gauge coils or sender unit up.
My parents came to visit just before Christmas break, so the car took the sideline for a little while whilst much needed repairs were done to the house and workshop. The decking was replaced, and the roof repaired to the workshop and the walls replaced where they had rotted out as a result of the leaky roof.
The workshop was made significantly more airtight than it was, the little window unit air conditioner was taken apart and the mud dauber nests all removed meaning it had a chance of dehumidifying and cooling the area.
I painted the walls and doors white to cheer them up a little. After having done that I decided that it was too plain and needed something to make it a bit more interesting.
I bought some oil paint and painted a mural of the car, which was a nice distraction from the fact the car wasn’t running well.
I stripped the top end off the engine again and removed the valves (with thanks to Lloyd from the H.A.M.B. for the tool), a couple of which were very very difficult to remove from their guides.
I cleaned all the valves up, and let the collets and springs soak for a while to clean them up also.
I made a tool from an old toothbrush and a length of wooden dowel.
This allowed me to soak cleaning fluid down through the guide and scrub away any dirt.
I then made a second tool from another piece of dowel and a worn-out piece of 220-grit emory paper. That was spun down each guide to gently hone it, then the brush used to sweep up any debris.
I then started lapping the valves into the seats- they had been replaced by the previous owner but not matched (nor cleaned, from what I can tell) so this helped until I reached the third exhaust valve which didn’t want to lap in evenly. It turned out to be bent, from having hit a spark plug- guessing someone put the wrong length plug in and started the engine.
I ordered a replacement valve and once that came in the engine was reassembled.
The valves are awkward to get at even with the correct tools, but eventually I put them all in and set the clearances by eye.
I bought some tube and fittings and reconnected the oil pressure gauge. Now all my gauges work (though at 14.4V on the alternator the temperature gauge over-reads significantly. In that picture it should have been pointing just below 180) which is a nice thing to have.
I connected up the vacuum system from the manifold through to the pump and up to the windshield wipers. The vacuum motor is tired and really needs a rebuild. The washer pump is also similarly tired so work needs to be done there to make better.
It is nice to see the parts going back on the car though. Each makes it one step closer to working well.
Onward and upward. With the air filter removed the Carter makes a nice noise with the throttle opened up. It does run smoothly now.
With the engine and transmission back together, I decided to finish up doing the things that are difficult to do with the engine installed.
I wrapped the wires that are now in place (lights and such) and tidied up under the hood.
I undid the clamp bolt and cleaned up the body of the alternator. 1100542 shows it’s a Delco 10SI, 63 Amp remanufactured unit.
I stripped the alternator down, thankfully Delco have the manuals online for their older models. There are 4 individual parts inside the end case; the rectifier bridge (silver finned heat sink), a capacitor, the voltage regulator (white plastic) and diode trio (orange).
The principle of the alternator is moderately simple. A magnetic field in the armature, created by passing an electrical current through a couple wound around it, rs rotated by the engine next to a series of wound coils (stator). As it moves past each coil winding, the change in magnetic flux generates an electrical current in the coil winding. As the magnetic field moves towards the coil, a positive field is created, as it moves away, a negative one is created. There are usually 3 windings (either in a Y or Delta configuration) so an alternator creates 3-phase alternating current. This is no good for a car battery which is direct current, so it is rectified through a bridge rectifier set of diodes before it’s connected to the battery.
This output is connected through the diode trio to the voltage regulator. The voltage regulator changes how much current passes through the winding in the armature, making the magnetic field stronger or weaker depending on how much voltage the stator coil windings produce.
The diode trio tested bad- two of the diodes are open circuit (do not conduct at all) and one doesn’t diode any more so that should be the root cause of the alternator not charging. The voltage regulator isn’t getting the voltage it needs from the output so isn’t applying voltage to the armature winding and the alternator is producing very little charge.
I readjusted all the valves. The manual states to make sure they are all set correctly.
I bought some new bolts for the rear engine cradle, rated 8 (strong for shear force) with the correct fine pitch thread. That was cleaned and reinstalled and the engine wired in temporarily.
It was good to see it back in. I set about reinstalling the ancillary parts and started to look at the manifold, which has never sealed well. It is made in two parts, with a “hotspot” flap in the exhaust that directs the exhaust around the outside of the intake by the carburetor before letting it escape though the downpipe.
It was suggested that I split the two parts and re-settle them to allow them to seat square against the engine. Easier said than done, as all four bolts were seized and all four broke upon attempting to undo them, despite heat and releasing oil.
I carefully center punched the remains of the bolts and started to drill them out.
I then used a thread tap to clean the last of the bolt from the threads.
The two most accessible bolt holes were straightforward, but the two at the back are obscured by the casting of the manifold and proved impossible to drill out straight. I ended up drilling them oversize and tapping the holes with a new thread.
I made a temporary gasket and reassembled the manifold, which allowed me to put it back on the engine. It leaks but the correct gaskets are many times thicker and take up a lot of the gap.
The original lower radiator hose was so badly rusted to the spigots I had to cut it to remove it. I took the old hose to the auto parts store and a replacement with the correct bend in was sourced. I cut it down to length and put the anti-kink spring inside.
I finished putting everything into the engine compartment that was required to make the engine run. I filled the radiator up with water and connected the fuel.
The three gauges that are currently connected all worked. Fuel gauge reads a quantity of fuel in the tank, engine temperature reads as it warms up and the ammeter reads a discharge.
I connected up the propeller shaft and took it for an experimental drive. The gears changed, it went forwards and backwards and overall worked.
The throttle linkage was very sloppy and had a lot of free play. This was causing the gas pedal to move the gearbox modulator lever quite a distance before the throttle began to open, with the net result the gears were holding until high speed before changing and under light throttle were quite harsh.
I added some springs to the connections to hold them all in line, peened the bar of the throttle down to remove the slack and readjusted eveything as per spec. The result was as hoped for; gears that change gently under light throttle and more positively and at higher speed with heavier application of the gas pedal.
I started to track down a misfire under light load, I checked the spark wires for continuity. They are all good, but the insulation is poor so I think new ignition parts are required (cap, arm, coil, wires, plugs).
I turned my attention to the cosmetics of the car because the weather had turned fine. I started to wet-flat the paint with dish soap, plenty of water and 2000 grit paper.
After finishing with the paper, I started to polish the paint with scratch remover cutting compound, then a finer grade polish, and finally wax.
The day became too hot to continue, as the polish was just flashing off, so I stopped. The improvement is noticeable.
I also masked up and painted the driver’s side hubcap with red lacquer. That made an improvement also.
I loaded the car back up into the garage, and looking across the hood, I was able to smile. It is beginning to look nice. Much more yet needed, but this is a good start.
Work continued on the gearbox with the arrival of a box of parts.
A brand new oil delivery tube (for the clutches), a pair of clutch lids for the drums, new clutch friction material and steel packs, a set of new bearings and some other odds and ends.
I started with the front servo, which was due new oil rings and a new main spring (the original fractured).
The front servo has a couple of independent pistons inside, separated by a couple of springs. It is all held in place by simple geometry and during assembly everything liked to get out of line. After a few failed attempts where springs launched themselves or the piston fell out past the rings I magnet to get it all reassembled.
I fitted new bearings (more on that later…) and started rebuilding the reverse gear mechanism.
The reverse piston is pushed back from being activated by a wavy spring steel washer. The original had broken in half. This appears to have been the reason the gearbox was taken apart originally. The broken part appears to have come free and become mangled up in the rear epicyclic gear set.
I took a bit of a break from mechanical parts of the gearbox to work on the wiring. I fitted the replacement new brake light switch, as the old one had failed.
I bought some new wire and rebuilt the headlight loom.
I redid the turn and park light wiring, as there were a bunch of Scotch-Lok connectors and excess wiring in the harness. I added a good ground and connected it all up.
The wiring was then terminated at the rebuilt terminal block.
I ordered some rivets, which are soldered to the end of a wire to form a terminal in bulb holders.
With the bulb holders rebuilt, I started to run new wiring under the dash.
This began to turn into a complex task, despite the wiring in the car not being too many circuits. The brake lights and front indicators all wire through the turn signal switch.
The original connector was loose to the switch and the wiring was a little crispy. I took the connector apart and started to de-solder the wiring.
This demonstrated just how flammable the old wiring is- it caught fire very easily and did not put itself out.
The harness was loomed up neatly, with wires for the brake lights, front indicator bulbs, wiring to the brake light switch and wires for the dashboard telltale lights.
I built the loom up for the dashboard and connectorized it for easy connect/disconnect.
I connected the dash up to test. All the lights work, the dash dimmer operates, the ammeter registers current and even the fuel gauge registers not-empty.
With wiring completed, I turned my attention back to the gearbox. I pulled the clutch packs apart and discovered a lot of metal debris inside, a lot of melted alloy.
I fitted new bearings to the clutch pack after cleaning it all up. The new parts fitted together nicely.
The clutches are made up of a number of rings, friction material rings with centered teeth that grab the sun gear and steel plates that locate on pins to lock the gearset solid and stop the thing being in reduction.
With all the clutch rings in place, the piston assembly then sits in the top and is held is place with a large snap ring.
The drums then locate onto the fluid delivery sleeve, which in the book calls for a special tool to compress the oil rings down for easy assembly.
I improvised and wrapped wire around the rings to hold them compressed.
The front drum went on easily because access is good.
The rear drum… not so much. However, both fired on successfully after a long fight.
I then started to refit it all into the case. I then started to run into trouble with it all not fitting. I decided I needed to order some more parts to adjust lash.
While I was waiting for parts I went back to working on the wires. Part of that included wiring for the heater fan. The fascia panel was particularly dirty so that was cleaned up.
The switch for the fan was rewired at the same time, the switch itself being in good condition.
I rebuilt the dome light because the switch did not work. It had corroded and the contacts had become poor and had caused the plastic to become distorted.
A little work with a craft knife and sandpaper saw the plastic in the correct shape again with the slider being spring loaded against the terminals.
I then had to rebuild the driver’s door switch as it has seen some water ingress and was also corroded.
Now the dome light and trunk light both operate (though the trunk light mercury switch is unreliable).
I fitted the electric antenna I had bought and tested operation, successful. No radio yet installed but it’s ready to go.
I had wanted to purchase an alternator that is fitted into a case that looks like the original dynamo generator, for two reasons. Firstly, the look of it and second, it utilizes the original mounting points. However, those are very expensive so instead I decided to build a bracket that mounts to the original points but correctly holds the alternator in line. Previously the alternator was mounted upside-down, with the main mounting point providing no reaction torque and the adjustment bolt hole holding it all up. As a result the alternator was sitting at an angle and the belt was slipping.
The new bracket holds the alternator in line with the pulleys and allows now for correct adjustment.
The alternator warning light won’t go out and I get just over 13 volts from it, so further investigation is required.
While I was working in the area, I cleaned up and painted the timing marks. There was a blob of white paint that covered all 3 marks (at 3 degree intervals). I found the timing was set very far off, close to 45 degrees. I re-indexed the spark plug wires and discovered the engine was very happy to idle smoothly when the timing was correct.
I saw with my timing light that the ignition wasn’t moving with manifold vacuum. Discovered someone had clamped the vacuum advance arm with the condenser bracket. I freed that up and found the screw holding the condenser was far too long, had fouled the mechanism underneath and the plate was bent. I corrected that so now it advances but it does move a little far. There is a bendable tab that limits how much advance is applied, which will need modification to prevent light throttle from being lumpy without impacting idle.
Between times I had a thought and decided to make a new clip for the driver’s side headlight beauty ring. I had some baling wire, which is nicely flexible but has all the strength of putty. So, I bent the wire to shape then heat-treated it with my propane torch.
The wire is heated to incandescent orange then quenched rapidly in cold water. This hardens the metal. A couple of repeats, then heating the metal up to a dull cherry red and letting it cool slowly brings back capability to be springy.
The headlight trim is now securely held in place, which is an improvement over the previous implementation courtesy of the previous owner of gooey sealant. Which, incidentally didn’t work.
A bit of a saga occurred with the gearbox. I couldn’t get the main shaft endfloat correct. Everything was too tight and would bind up solid. I figured perhaps a bearing hadn’t seated well so gently tapped the mainshaft against the rear drum. This translated the force to the oil pump, which was the root cause of the problem. The bearing hadn’t seated correctly when I put it in and was sitting proud. As a result the retaining flange on the oil pump shattered (I think it had been weakened in the past). I ordered a new oil pump and the correct thickness shim which allowed me to reassemble the gearbox.
The brake bands need to be carefully preadjusted for correct operation. The manual shows the use of a special tool- with care vernier calipers can be used. The setting is to dial the band in against the spring until the distance from the back of the servo to the actuator pin is 5 7/16″.
With tension set, the locknut is tightened down and the rear band is done.
The front servo needs to be pushed in 300 thou’ and the band set snug at that position. The servo case has a plug in the end which is tapped blind so it seals. The brass insert is a hydraulic fitting that I tapped a thread through to allow a bolt to be screwed down and push against the piston.
I filed and rounded end onto the bolt and polished it so it could turn and push against the alloy piston without damaging it.
A little bit of mathematics showed with the thread pitch of the bolt 5¾ turns were required for 0.3″ of travel. I set the front band against this and reinstalled the servo plug.
I reassembled and painted the gearbox.
I then cleaned up the flywheel and bolted the gearbox to the engine. I gave the engine an oil change and filled the gearbox with ATF. I started the engine up and engaged Drive and was greeted by the gearbox changing through all gears as the revs were brought up.
I continued to work on the parts of the gearbox, stripping everything down. A large volume of swarf, metal chips and bits of burned friction material from the clutches had found its way into the hydraulics.
I managed to clamp down and disassemble the clutch packs. All the friction material (an organic fibrous material and come cork) on the friction rings was gone, burned to a crisp. The six light spots are bright patches worn into the metal.
The rear drum was significantly more difficult to take apart. It is not internally spring loaded and is a tight interference fit. It was less badly worn but still unserviceable.
With the drums apart, I checked the thickness of the thrust washer shims. They were below limits.
I ordered a pair of new ones. The copper is completely worn through on one of the old ones.
The cleaning continued. I disassembled the valve block, which was all partially jammed up with dirt and swarf. The bores and pistons were all in good shape, and upon reassembly all move well.
I started to disassemble the rest of the hydraulics. The front servo relinquished a fractured spring. This is going to be the main causal reason the gearbox failed, with this slipping there is extra stress on the clutches.
I invested in a large screwdriver and was able to remove all the plugs from the front servo. The 4-3 downshift valve (above) is a good example of how dirty the hydraulics in the system were.
I had a little difficulty disassembling the front oil pump, because the thing was held together with 4 Fillister head screws, all of which were stuck fast with sealant and all had been previously rounded off. One needed to be sawn down and another drilled. The pump itself was in surprisingly good shape inside, considering the amount of swarf in the rest of the pipes. The overpressure relief valve (the dark circle on the bottom right of the right hand assembly above) was also jammed, so that was freed up and cleaned out.
The rear servo is fully spring loaded. It holds the rear band on when the gearbox is not pressurized, meaning that if reverse is engaged it has both reverse and 3rd gear selected simultaneously. This effectively locks the gearbox solid and acts as a parking brake.
I managed to reassemble the rear servo without losing any parts or breaking any of the oil rings. There’s enough tension in the spring to launch the thing into orbit.
Finally, the reverse gear assembly.
The reverse gear cone is a little scored- turns out there’s been some swarf stuck in it and that’s caused hotspots. I picked all the steel out of the alloy. Thankfully this mechanism only comes into contact with the drum when reverse is engaged, and only slips of the vehicle is moving when that is done.
In contrast, a new drum is fairly smooth. (Above).
The annular piston that forms the central drum cone is held in by a disc and a snap ring. The disc needed to be pushed down, compressing the springs so the snap ring could be removed.
I trimmed the base of a valve core flat so it would seal against the case.
Application of compressed air saw the piston removed. Surprisingly, this was the only part of the system not full of swarf and dirt. The seals were fairly new (though in bad condition) and the roller bearing at the back is quite new also. The reason for this became apparent when I found half of the wavy washer under the retainer in the drum. It appears that fractured, came loose and jammed the reverse gears, causing a bit of damage. Someone had taken it apart, done half a job to pull the pieces out and thrown it back together.
I overhauled the reverse mechanism. Removed the seals, cleaned the grooves they sit in. Whoever was inside the gearbox previously neglected to do this.
The sealing surfaces were not very clean so I rubbed then back with 1000 grit paper until they were smooth.
New seals were applied.
I reassembled it all, having to improvise another special tool to get the outer lip seal to be able to get past the step the static outer cone sits in. Now awaiting new bearings.
The governor assembly was also in need of cleaning. The smaller governor weight would stick at the bottom of it’s bore because it was worn. I lapped it carefully with some metal polish and now it doesn’t jam- the piece it used to get hung up on doesn’t need to seal, it simply needs to prevent the piston bottoming out.
The governor is two parts- the left hand one has a large weight and opens up that valve at low road-speed. That engages the reverse gear lockout pin. The smaller of the two pins is thrown out at higher speed, and provides pressure to the valve block to engage different gears as the speed of the car increases. If the pin sticks then it will change gear too late each time.
Strip-down of the gearbox began in earnest. With the service manual in hand, I was able to determine the correct procedure to dismantle it.
The manual states the first thing to do is to upend the gearbox and mount it in the gearbox holding jig. I don’t have a jig so it just sat upside down on my new bench instead.
First impressions upon removing the oil pan were not good. There was a lot of black gunge, which draining the fluid belied, being rather clean red when it came out.
I flushed a lot of the dirt out, which left behind a lot of metallic swarf and a few molten globules of metal. Not a good start at all. I was hoping at this point it was merely remnants of a burned up clutch plate.
I thoroughly cleaned the oil pan and leveled the gasket surface with my orbital sander.
I then cleaned the old paint and rust from the exterior of the oil pan. Originally the pan was zinc coated and not painted; somebody had painted it gray in the past.
The original color is battleship gray, but I opted for Solstice Blue again.
I removed the gauze oil filter. Somebody had added blue sealant to the rear pump pickup point. This made me cringe.
I began to follow the manual to remove the control block, reverse control and band servos.
That left the core of the gearbox in place; the front and rear planetary sets and the reverse mechanism. I removed the reverse gear assembly and undid the main bearing cap holding the two planetary gear sets in.
I removed the snap ring holding the rear assembly in place and pulled it off the fluid delivery sleeve (the section that provides hydraulic pressure to the clutches). At this point I was able to determine the source of the swarf and metal shavings in the oil pan.
One oil control ring was fractured and the sleeve itself was very badly scored. The sleeve should not make contact with the drum at all where the rings are.
The bearing surface showed it had overheated and worn away significantly, allowing the drum band system to pull it off center and force contact with the oil delivery sleeve.
Removing the snap ring from the front assembly showed similar damage to the bearings, allowing it to be well off center and tear up the fluid delivery sleeve on this side also.
The main driving shaft (output of the primary epicyclic to the fluid coupling torus) is made of much tougher metal than the fluid delivery sleeve and has escaped much in the way of damage.
Thankfully, parts are available and I will be able to rebuild all the damaged sections. I need to take the assemblies apart and check the clutches for condition.