Category Archives: Mechanical

Pontiac renovations, part 25.

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.

Front drum

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.

Rear drum

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.

Micrometer

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.

Valve block

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.

Servo spring

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.

4-3 downshift valve

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.

Rear servo, in pieces

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.

Rear servo, assembled

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.

Reverse gear

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.

A good drum

In contrast, a new drum is fairly smooth. (Above).

Special tool

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.

Modified valve core

I trimmed the base of a valve core flat so it would seal against the case.

Reverse cone removed

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.

Removing seal

I overhauled the reverse mechanism. Removed the seals, cleaned the grooves they sit in. Whoever was inside the gearbox previously neglected to do this.

Cleaning sealing surfaces

The sealing surfaces were not very clean so I rubbed then back with 1000 grit paper until they were smooth.

New seals were applied.

Reverse gear assembly

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.

Governor and rear oil pump

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.

Pontiac renovations, part 24.

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.

Upside down

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.

A volume of dirt

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.

Dirt flushed

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.

Clean oil pan

I thoroughly cleaned the oil pan and leveled the gasket surface with my orbital sander.

Clean steel

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.

Painted oil pan

The original color is battleship gray, but I opted for Solstice Blue again.

Oil filter

I removed the gauze oil filter. Somebody had added blue sealant to the rear pump pickup point. This made me cringe.

Parts

I began to follow the manual to remove the control block, reverse control and band servos.

Planetary sets and reverse

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.

Rear assembly removed

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.

Oil delivery sleeve

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.

Overheated bearing

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.

Main bearing

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.

Main driving shaft

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.

Pontiac renovations, part 23.

August rolled around again, and as it is wont to do, has been warm.

Warm in the garage

Having spoken to a radiator shop and been quoted a significantly higher price than I could afford for repair, I decided to set about and attempt a repair on my radiator myself.

Filler neck

The filler neck had what looked like some sort of putty or mastic spread all around it in a messy fashion.

Solder

I pried at it a little with a screwdriver and a large chunk fell off, showing it to actually be lead solder. Whoever put it on did it badly.

Filler neck removed

I decided to cut my losses, and while holding the cap in my big pliers, I heated it up with my gas torch. It popped off with relative ease, showing a lot of dirt where it had split away from the top tank, and was being held in place around about one fifth of it’s circumference.

Cleaned with wire brush

I used a steel wire wheel to clean both the top of the tank and the filler neck. I then added soldering flux, heated them both and tinned them by adding solder to each face, ensuring good adhesion.

Filler cap soldered in place

I then lined the two pieces up and heated them so the solder flowed and melted together. Hopefully a permanent repair.

Big gas flame

The radiator had been leaking along the seam between the fins and the top tank. I cleaned it up and attempted to solder it up with my gas torch, which proved to have a flame too broad and too hot to easily work with.

Soldering with big flame

I was able to make a good seal, but it wasn’t the tidiest of work. I went to the store and bought a torch with a much tighter flame pattern, adjustable temperature also.

Small torch

The tighter flame allowed me to control the heat better, and so I soldered up the rest of the seam.

Seam soldering complete

This method allowed me to improve my technique and make a much more tidy repair.

Pressure testing

I built a rather Heath-Robinson testing rig, consisting of the garden hose and some duct tape.

Crack

With the seam no longer leaking, the pressure testing identified a small crack in the top tank.

Flux

I cleaned the area around the crack mechanically with a wire wheel, then chemically with acid flux.

Repair

I soldered the crack up and tested it again. This time it didn’t leak.

A bit of black paint

I cleaned the metal down of old flaking paint and gave it a coat of semi gloss black. I ran out of paint, will continue the rest with a new can.

GM Hydra-Matic notes

As a side-note, the gearbox is specified in a strange way compared to automatic gearboxes I am used to. Most modern automatics have the engine drive the torque converter housing, which turns the pump, and the inner vanes of the torque converter drive the mainshaft. The output of that is then passed through the reduction gears.

Pontiac specified that the vehicle should not creep at idle, in Dr (drive) position. Even with the engine idle specced lower than the manual gearbox version (375 versus 550 RPM) the fluid coupling imparts enough force at 375 RPM to move the car forwards. At a guess the rationale for this was to not alienate their customers who had never experienced an automatic gearbox before.

Get in, sit down, start up and put it into gear, look there, the car does not move.. gently squeeze on the gas pedal sir.. there, the car begins to move- press a little harder, and just take your foot off the gas and onto the brake to stop. Yes, just like that sir, isn’t that a fantastic marvel of modern technology?

To stop the car from creeping yet retain an acceptable idle (the engine gets a bit unhappy as it approaches 300 RPM or lower) the engine drives the outer coupling housing directly (which is not connected to either inner torus) and that is taken inside the gearbox and through a 1.45:1 epicyclic reduction gear. The output of that is then sent back to the driving torus at 7/10 the speed of the input. As a result the driving torus is turning at about 260RPM at idle. At this speed it does not impart enough torque into the driven torus to move the car.

The output of the driven torus goes back deep inside the gearbox and drives a second epicyclic reduction gear of 2.63:1 ratio. The two gears driving each other in reduction results in an overall gearbox ratio of 3.82:1 in first gear.

The epicyclic reduction gears can be locked by the internal clutches to either reduce the output speed or be locked solid at 1:1 ratio. Combining the 2 clutches in a binary style fashion (00 01 10 11) provides 4 reduction options- 3.82:1, 2.63:1, 1.45:1 and 1.00:1 (direct).

The final drive passes through a third epicyclic gear, which, by holding the planet set still with a clutch will reverse the motion of the output shaft and provide a reverse gear. It is also locked out internally to first gear full reduction only- without that there would be 4 speeds in reverse with a top speed of about 60mph. Not ideal!

The gearbox also has a few interesting design features- two oil pumps, one on the engine driven side, the other on the output shaft. This is to allow oil pressure to be built up as the vehicle is towed, for two reasons. First, it provides lubrication without the engine running, second it provides oil pressure so that if the transmission is dropped from N to Dr it will engage a gear and be capable of bump starting the engine.

The oil pumps are designed to provide high pressure at low speed. This pressure is kept constant by a spring relief valve. The gears are selected by valves with varying strength springs. A governor valve (centrifugal weight that spins with road speed) increases pressure on the valves as the road speed changes, initiating gear changes. The throttle pedal is attached to the gearbox and serves two functions. First, it opens a valve that applies main pressure to the opposite side of the gear shift valves, meaning greater governor pressure needs to be built up before the valves will move and gear changes occur. Second, as the gears are changed it adds boost pressure to the servos so the bands clamp more firmly and quickly. This makes low speed, light throttle gear changes smooth to engage at low speed, and hard acceleration changes to snap tight quickly at higher road speeds.

It all sounds good but there are a lot of moving parts that all need to move in synchrony. If something jams, it’ll either disengage drive fully or attempt to engage two gears at once which causes undesirable operation, neck-snapping jerks in the drive or a redline-flare of the engine. In this case, it would change gear at a much higher RPM/roadspeed than it should have, and only when the throttle was snapped shut. Hopefully that can be remedied.

Pontiac renovations, part 22.

I started to strip down the parts of the gearbox I knew how to take apart, having ordered the service manual but still waiting for it to arrive.

Fluid coupling driving torus

The fluid coupling is all held together with a large nut, secured with a tab washer. The tab washer was a good idea by the engineers because the nut, initially torqued to 50 lb/ft, was loose.

Fluid coupling parts

The large drum section connects directly to the engine flywheel (and represents a significant rotating mass to act also as flywheel) and the two torus sections sit inside and drive each other.

Bellhousing

The inside of the bellhousing was fairly clean, though it is easy to see where the O-ring has been leaking past the torus housing. The inner part of the torus is kept full of fluid by the pump and at about 40psi by a pressure relief spring. The mainstay of the oil is kept in by two piston rings on the inner edge.

Gearbox, bare

The bellhousing came off easily. I cleaned the machined faces up and inspected the seal.

Side pan

I removed the side oil pan from the gearbox. It was rusty and the previous keeper(s) had painted it gray over rust and dirt. I cleaned it up with orbital sander and wire wheel.

Painted pan

It then received a couple of coats of Solstice Blue paint, as a test. I see no reason why engine parts cannot be any particular color. It won’t last but it’ll start out looking nice.

Ignition timing clamp

I cleaned up the distributor clamp, which has a moderately helpful pointer (which will need to be reset) to show degrees of advance or retard against TDC (Top Dead Center).

Timing marker

There’s a cast vee in the case of the engine to refer against, and the distributor also has a knurled wheel to fine tune the timing.

Service manual

The service manual arrived. It’s in good condition, printed in May of 1951. It gives a good explanation of how the gearbox actually works.

Measuring main shaft endfloat

I clamped my dial gauge to the gearbox and measured the endfloat. This is set by a bronze thrust washer buried deep down at the back end of the gearbox. 19 thou’, slightly over limit. If I can get a replacement shim I’ll fit it, else that’s on the next big service.

Engine, in turquoise green

I decided to finish up something I had started a good while back. I cleaned the engine down and gave it a coat of paint.

Other side

It is meant to be something close to Brunswick Green, but I cannot find that color anywhere, and the nearest green (Hunter Green) is horrible. So, I went slightly out of the box and painted it a color called Deep Turquoise. It’s close to the mid sixties Pontiac V8 color, And goes well with black parts attached.

Harrison 3127575

I brought the radiator to a shop in town, and their main guy took a look, measured it up and said it would need to be recored, at $460 for the core and about 6 hours of labor to total approximately $900. I am going to clean it up and attempt to plug the hole and make do for now. Sometimes these things price themselves out of the market.

Pontiac renovations, part 21.

July has been a busy month; an early hurricane saw me climbing on the garage roof in the middle of the storm to nail down loose corrugated iron panels.

More work with orbital sander

I continued to work on the firewall of the car, removing old bubbled paint and rust.

Frame rail

I also started to clean up the X brace of the chassis, before putting the engine back in rendered access impossible. Rust converter solution, black paint, underseal then a coat of black on top to cover up the brown of the underseal.

I put some paint on the firewall to protect it, which was a marked improvement. My neighbor had offered to weld the horns to the brackets, so one afternoon this was completed.

Welded brackets

A quick coat of gloss black enamel…

Gloss black

Then a test fit to the firewall. They don’t look out of place a great deal, being a little too modern.

Horns fitted in place, with relay.

Then, with that diversion over, it was back to scraping dirt and rust.

Mostly old dirt.

This was scrubbed and painted up to try protect the metal again. It’s all in remarkably good condition for its age.

Undersealed and painted black.

With the lower sections cleaned and painted, I started on completing the firewall. It was scraped down and painted.

First paint coat.

I then masked off along the body pressing lines and coated the lower sections in rubberized underseal.

Undersealed.

The factory had applied a similar coating to the underbody, but had left it unpainted (plus they didn’t mask, they just sprayed the stuff on from a distance at high velocity) which looked a bit ugly. Similarly I decided that I was not going to leave it like that, as I didn’t like the blue/brown contrast.

Underseal painted blue.

I painted over the top of the underseal. Looks quite acceptable now.

Inner fender apron

The driver’s side inner fender apron was looking a little worse for wear. Originally the battery was mounted hard up against the sheet metal, and years of leaking acid had taken its’ toll.

Paint removed from sheet metal.

I sanded the sheet metal down. The wrinkles look like accident damage but are in fact factory produced. The metal is a complex shape and did not shrink cleanly when it was stamped. As an internal panel this was evidently deemed acceptable.

Channeling my inner Bob Ross.

I applied rust converter solution to the panel, which dried quickly in the heat.

Semi-gloss black (still wet)

The entire panel then received a couple coats of black paint. A significant improvement.

A little bit of a hallmark day; I started to put things back onto the car. The brake pedal was reattached and the kick plate fixed into place.

Grease gun in action

I bought a decent grease gun, as the car has many greasing points that need regular attention. I started with the brake pedal hinge.

Steering box, being cleaned

I then cleaned all the old grease from the steering box with gasoline and a paintbrush.

Grease.

It was then refilled with John Deere Corn Head grease, which looks like green ketchup. That was squeezed into all the bearings.

Steering.

I then reassembled it all, adjusted as much slack out as I could and rejoiced at brakes AND steering. The steering box is worn and really needs the gears and plain bushings replacing but it’ll do for now.

Dimmer switch.

I then cleaned up the contacts and body of the headlight switch, and refitted it to the floor. Finally, the carpet went back down in the cabin which is a nice change.

Vent duct, rust.

I cleaned up the driver’s side fresh air vent duct, as it’s on view in the engine compartment.

Clean vent.

Who doesn’t like gloss black enamel? It gives a nice finish. That’s tidy enough to refit now.

Draining gearbox oil.

I turned my attention back to the mechanical parts. I drained the gearbox of oil, which looked a really very good color- it’s not done many miles since someone was in here last.

Removing torus bolts

The fluid coupling torus housing is in two pieces. One half forms the engine flywheel plate, and is held together with 30 bolts around the periphery of the assembly.

Gearbox, split.

I was able to put a bolt in the top of the casing and use my engine crane to separate and move the gearbox away from the engine. It is too heavy to lift manually, and as such cannot be put on my workbench. I didn’t want to work with it on the floor so built a workbench to put it on.

Workbench.

I lifted the side pan off to inspect a little. While fairly clean inside, all the mechanisms are under significant spring tension and I didn’t fancy undoing things before knowing the disassembly procedure. Service manual is in the mail.

Control valve and reverse gear mechanism

As such, I went looking for other things that needed to be done while I wait for the manual to arrive.

Fiberboard insulation, broken

The headlight connector blocks were in very bad shape. The insulators are made from fiberboard and hadn’t stood the test of time well.

Brown plastic

I took some brown plastic, drilled holes in it and cut it to length.

Notches

Filed the notches along the length that prevent the connectors rotating.

Then cleaned up and attached the metal connectors. Headlights, sidelights and turn signals connect to this block. Ground goes direct to the bodywork.

Attached to the car

Pleased with that result, I made a second one for the other side. Unfortunately half of the connectors are missing, so that’ll be other connectors in their place.

Passenger side connector block

This is beginning to pave the way forward to rewiring the car. Any progress is good progress.

Pontiac renovations, part 20.

Windshield defroster heater

I continued dismantling the engine compartment, from the firewall was removed the windshield defroster heater. It was disconnected when I got the car, and had shown signs of leaking.

Heater box in pieces

I spoke to a guy who rebuilds the heater valves. This one is a thermostatic Ranco valve, and it leaks around the spindle seal. The thermostatic portion of the valve was checked and is fully operational.

Heater matrix

I flushed the heater matrix out. Not much dirt came out of it, surprisingly. It is free flowing both ways and doesn’t appear to leak.

Orbital sander

I buzzed the rust and paint off the heater box with my orbital sander.

Outer clamshell

I applied rust treatment and painted the shell semi-gloss black.

Removing rust

All the screws were very rusty. They looked as though they were originally plated with chrome, but that was long gone. I sanded them down smooth in my drill.

Shiny screws

The screws were then pushed into the side of a cardboard box.

Then the screws were painted gloss black enamel.

Reassembled heater box

The heater box was then greased (spring loaded parts) and reassembled. Once the valve is rebuilt, it’ll go back onto the heater frame and be connected via hose to the rest of the system.

Horn, drilled

Someone kindly sent a pair of (mid sixties) Delco horns for the car. While they aren’t visibly the same, the tone they produce is the same. The brackets were too short and at the song angle so I drilled out the spot welds to remove the brackets.

Steel

I bought a length of bar stock of the same size as the original brackets.

Measure and mark

I measured up, marked out, drilled and filed two brackets to shape.

Horn brackets

A few holes drilled for welds and the brackets are offered up to give a visual representation.

Horns with brackets

Having filed surfaces down I decided to clean up and paint the horns. They were rubbed down with a wire brush and painted up in gloss black enamel, as per original spec.

Nice finish

I do like gloss black enamel. It produces such a wonderful result straight out of the can.

Paint scraper

Being as I was working in the firewall area, I decided to start removing old rust and paint, in order to be able to apply new.

Bare metal

I ran out of time after this photograph was taken. There’s a lot of nooks and crannies to sand, with some areas that I cannot fit the sander in. A finger sander/powerfile would be the tool of choice here.

5128

The original written code for Starmist Blue was written on the shell. I had sanded over it but it’s etched into the metal. It’ll not be visible after paint, but it’ll be there.

Glove box badge

The glove box badge was originally all silver. However, over the years the silver has fallen off. Previous keeper had painted red over the back, which looked horrible as a lot of the silver was still present.

Brass brush

I attempted to mechanically remove the paint from the back of the badge. It did remove quite a lot but still, not enough.

Partially clean

The net result was poor. I spoke to a few people and they suggested oven cleaner. Apparently it doesn’t attack the plastic but removes the paint.

Clear

They were not wrong! All the paint came off nicely.

Lettering

I dripped cream colored paint into the lettering with a piece of small gauge wire.

Lettering done

With the lettering looking tidy, I took my pillarbox red paint and converted the back side of the plastic.

Red

Overall, very pleased with the results.

Restored badge

It looks good now. Not perfect but a lot better than it was.

Glovebox

Finally reattached that to the car. It needs to look nice, it can be seen from outside and the passenger has it right in front of them all the time.

Pontiac renovations, part 19.

Car, pushed outside.

I pressure washed the car and the engine compartment down, working to remove more dirt from the chassis.

Cleaner engine compartment

With that washed down, the car was parked back into the garage and left to dry.

I ended up having to buy a couple of tools. An inch-and-a-quarter socket to remove the nut from the bottom of the Pitman arm and a puller to remove the arm itself.

Puller

That allowed me to remove the rather sizeable nut holding the Pitman arm on.

Securing nut and washer

Which then allowed me to pull the Pitman arm off the cross shaft.

Pitman arm splines

With the arm removed, the cross-shaft could then be removed and checked for condition.

Cross-shaft

The ball race was a little slack but otherwise good, the plain bearings that carry the shaft are worn, and in need of replacement but for now I’m going to repack the box and come back to the problem.

Steering box lid
Steering box

I took the ball race apart to clean it up in gasoline. There’s a mix of the wrong type of grades of grease in the steering box and a lot of it had congealed badly.

Soaking in gasoline

Reassembled, tightened up a little then peened the nut. Most of the slack in the ball race is now gone.

Clean cross-shaft

Then to stop it from deteriorating, I gave the steering box lid a coat of paint.

Painted black
John Deere “corn head” grease

I bought a tube of corn head grease, a polyurea blend grease that will sag down once it’s been pushed out of the way, ideal for this application. It’s also designed to only become fluid where it’s worked. Around seals it stays very solid and doesn’t leak out so badly.

Chassis leg and brake master cylinder

I then started cleaning up the chassis leg on the driver’s side. The brakes needed looking at because pressing down on the pedal would sometimes cause it to jam, and it would always make a bad noise.

Bent fillet

The fillet plate had been installed incorrectly, was bent and fouling the brake pedal.

Rust treatment

I hammered it flat again, rubbed the rust down and applied rust converter.

Fillet painted and in place

I painted the panel up, and fixed it in place correctly.

Sounds deadening material

The original sound deadening was added back to the fillet.

All set in place

The clutch pedal blanking plate was fitted, after having been found sitting in a crook of the chassis, which looked like it had been there years. Then the top sections were added. Looking better and the pedal moved smoothly past it.

Brake pedal

Then, I took it all apart again to remove the brake pedal. The clevis pin was missing it’s R clip, and wouldn’t come out to be serviced. I ended up having to hammer it out. Repainted everything up after that.

Painted pedal

The grease point was a large glob of dirt, and upon removal, showed that it had not been greased in a long time.

Grease nipple with old grease

That was all cleaned, the operation of the nipple was checked, and everything reassembled.

R clip

I bought a new R clip for the clevis.

Paint

Finally, I finished cleaning the area and started to add some paint to the chassis.

Pontiac renovations, part 18

Engine, stripped.

I stripped all the ancillary parts off the engine, partly in preparation to clean and paint, partly to reduce the weight while lifting because the gearbox needs to be split from the engine.

Clean gearbox.

I started to degrease the gearbox in prep for removal. The manual states to make sure everything is scrupulously clean before beginning any work at all on the device. I can see why, there’s no filters to clean any dirt from the oil. That may be the reason it’s not changing gear, too.

Buick Sonomatic.

I turned my attention to the radio at this time. I bought a similar set from a 1956 model car- the internal structure of the radio being somewhat similar to the ’51, with the intention of removing the tuner section and replacing it, along with using a few parts to convert the ’51 radio natively to 12 volts operation. Surprisingly, the ’56 radio actually still worked when powered up. This was a good thing, it at least showed I had a good base to start from.

Chassis comparison.

The later model radio uses a slightly different audio amplifier (transformer phase inversion rather than active tube operated inversion) but the rest of the RF and IF is very similar. The IF stage has been cheapened a little and the component count is a little lower. Overall the ’51 is a better quality design, at the behest of higher power consumption.

Power supply transformer.

I librated the 12V supply transformer from the newer chassis, along with the vibrator socket.

Transformer can open.

For some reason, the manufacturer decided to put a capacitor inside the can they potted the transformer in, then crimp it closed like a can of spam. I carefully opened the lid and removed it, instead favoring a flying lead, so an external capacitor can be used instead, saving having to open it up again.

Broken tuner case.

The tuner and oscillator coil housing was suffering from zinc pest and had fallen apart. I removed it from the chassis, and it completely broke into two pieces, the ends where it was crimped crumbled like pastry.

Removing retaining lugs.

I tried to squash the lugs down on the new one to where the frame was removable, but that didn’t work. Instead, I ended up removing the lugs entirely by grinding them down with my Dremel.

Tuner frame removed.

The frame was carefully removed, however it is still strong, not weakened like the old one.

New coil frame on old tuner.

The coil frame fit the old tuner perfectly, bringing the assembly back into line, as the old coil frame had expanded in size.

Securing the lugs.

I hammered the flares back into the securing lugs to hold the coil frame into place.

Circuit board, aligned.

Fixing the circuit board to the new frame straightened it out. The entire tuner assembly now moves correctly without binding.

Multi-cap can.

I gutted the main multi-capacitor can, which contained 3 separate devices. It will be re-stuffed with modern capacitors, and will look the same when mounted in the chassis. It was also polished, because shiny.

Pontiac renovations, part 17.

Having fitted the air cleaner assembly to the engine to test, I decided that there was no time like the present to finish cleaning it. I had done the main body but had the air cleaner element and the oil bowl were still dirty and as-found.

Oil bowl

The caked-on dirt- very fine prairie dust mixed with decades-old oil had done a moderately good job of protecting the metal from corrosion but it was time to clean it up and use paint for that purpose instead.

Bare metal.

All the dirt came off with some elbow-grease. The metal is in good shape for its’ age.

Primed.

The outside was given a coat of etch primer, after having been wiped over with rust converter.

Gloss black enamel.

Final coat in black enamel. It hardly looks black, it reflects so much light. This enamel gives an incredible gloss straight from the spray-can.

Dirty filter element.

Next up, the filter element assembly. Again, more of the same scrub, scrub, scrub.

Filter element coming up clean.

Again, it came up remarkably well to bare metal with just a wire brush.

New filter mesh added to element.

All of the original filter mesh was gone. I’m not sure if it was cotton wadding type or steel, but some mice had been in there and had left none at all.

Filter element painted.

The inner element assembly is visible from the outside, so again, primed and painted in gloss black to match the rest of the assembly.

Entire air cleaner assembly fitted to engine.

All together and looking rather good, for the first time in many years.

Checking alignment and clearances of air cleaner.

I adjusted the mounting bracket that I had made, having seen a photo of a factory install. the filter sits almost directly over the mounting stud, with just enough clearance for the water pipe to the top of the radiator.

Washer bottle frame.

Next up, I did a little research and found that only the later Trico model screen wash brackets were blue. The early ones were plain mid-silver.

Pale blue-gray final color.

I chose a very pale blue instead, keeping the the car’s “blues” theme.

Paint color testing.

I experimented with some new paint colors. Off-the-shelf is a poor match for any bodywork colors on the car. On the left of the arch, by the washer frame is French Blue. On the right is navy. I think the navy will possibly tie in better because it’s close to the color of the roof.

Trico screen-wash reservoir and pump.

I bought a used washer pump/bottle off eBay for a good price. It was complete and looked to be in good shape. I took it apart, found the seals to have dried up over the years. Pressed them flat again and cleaned it all up.

Dissolving old under-seal.

The outside of the jar was covered in under-seal over-spray. It was left to sit in gasoline for a couple of hours and it all wiped off.

Jar fitted and filled.

Keeping with blues on blues, it was filled with fresh screen-wash and tested. It works in a strange fashion- there’s a spring-loaded double-ended plunger into two separate cylinders. Vacuum is applied to the top cylinder and the piston moves up, bringing the lower piston up and drawing fluid in from the jar. Release vacuum and the spring pushes it back down, expelling fluid from the top pipe in a stream until the piston bottoms out.

Delco radio set.

Next “new” item was a radio set. the car did come fitted with a radio but it was a “modern vintage” style tape deck. First, it didn’t fit, second it was missing a dial knob, third it was ugly. I decided I was going to retrofit the original AM Sylvania/Delco radio. They pop up on eBay from time to time in varying states of disrepair. This one looked moderately good and had the correct dials to match the rest of the dials in the car. There are four variants of knobs that I’ve seen, depending on what model variant you bought. Plain black plastic for the basic model, black plastic with a silver insert for the standard, silver outer with a black insert for the Deluxe (what mine has) and all silver (I think for the Catalina Coupe).

Undoing the front panel.

Disassembly of the unit was straightforward, just a number of 1/4″ bolts and a few nuts holding things in place. My idea was to gut it and fit something modern if it was in bad shape internally, or refurbish and restore if it was in good shape.

Radio circuitry and tuner.

Inside, it’s in really quite good condition. It’s pre-PCB so all the components interconnect each other and solder directly to the chassis in places. The tuner was jammed up solid.

Lubricating moving parts.

All the moving parts were lubricated. The tuning mechanism was then free to move, including the preset buttons. Unfortunately the metal case that holds the tuning coils has what is known as “zinc pest”, where lead impurities in the alloy react and cause crystalline fractures to grow. The metal then becomes weak and breaks like shortcrust pastry. It has expanded a little and bent out of true but for now isn’t too bad.

Front panel, ready to be cleaned.

The rear of the case is painted silver and is in very good condition. the front had been painted black and was covered in surface rust. I sanded it down with fine grit paper on my DA.

Front panel, stripped.

Back to solid, clean metal. Most of this will not be visible as it is mounted behind the dash, with just the chrome dials and scale showing at the bottom. The sound passes out through the large circular grille in the middle of the dash.

Front panel, still wet in satin black.

It was given a coat of primer and then a coat of satin black paint, to match the original finish.

Copper coat.

The speaker mounting screws would have been untreated steel originally, and as such had also gone rusty. I scrubbed them down with a wire brush, cleaned them further with ionic removal in a salt/vinegar bath and then plated them with copper.

Nickel coat.

The copper coating was then given a nickel coating to protect the screws and give a modestly shiny surface.

Dial knob comparison- dirty vs. clean.

The dial knobs were very grimy.When the set first arrived, a cursory glance looked to be missing chrome in places. It turned out to be thick dirt, all of which cleaned off with a wire brush.

Radio reassembled, clean.

I test-refitted the front panel, bezel and knobs. Looks much better than it did.

RF, IF and audio pre-amp section.

I turned my attention back to the circuitry. It’s a bit of a mess of seemingly randomly-placed components but there is a degree of logic to the assembly. I had started to measure some of the values (the Rider manual uses M notation for resistance in the k scale, and Meg for M) and quickly discovered that my tube meter was not functioning.

Heathkit VTVM in pieces.

I took it apart and had a poke about. The tubes both lit so the heaters were all good, there was voltage at the plates and no signs of any stressed components on the board. I twiddled the calibration pots but that was not the problem. It ended up being a poor contact on the connection to the meter. There’s a battery in the circuit that gives a permanent positive bias and that had made the brass peg of the meter’s terminal corrode slightly.

Working meters.

I cleaned the terminal up, re-calibrated the meter as per the factory manual and checked the voltage of a 9v battery I had on the desk. Both meters agree, which is good. I ran out of time to carry on, but all the test equipment is in place. What I need now is a 12V power transformer, the 12V variants of the tubes, possibly replace the rectifier with a couple of diodes and add a modern solid-state vibrator to generate the high voltage.