Monthly Archives: June 2019

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.