Projects Mild custom '51 Pontiac Chieftain

Thanks, Phil. Very interesting.
I might point out that a brake hone works well for some of those inner seal surfaces.
Also, trans-gel comes in various viscositys , depending on conditions. The thick stuff does a good job holding those seal centered for re-assembly.

 

Yup, the manual states just to use petrolatum- I used regular transmission fluid and ingenuity.

Phil

 

The drums slot back in place and tighten down into the locating dowel. The cap tightens down to 65lb/ft to hold everything in place- it really is the core of the gearbox.


New bushings go in. Manual suggests to use petrolatum to hold them in place. This is a good idea because they like to fall out and get clamped in the wrong place and get all bent.


Drum held in place and bolts torqued down. First test, you'll see the rear band isn't in place in this picture.


There's a good reason for it- the copper disc in removing there is the overall spacer washer, and is available in a number of thicknesses to take up the endfloat in the output shaft.


I had made a mistake and hasn't pressed the bearing in the front oil pump fully home. As a result the endfloat was in the negative. With the washer removed I had a reasonable amount of lash. I decided foolishly to use the main shaft as a slide hammer and tapped it a few times to settle things.
I was thinking that the force imparted was upon the second drum and taken up by the center bearing. Not so, it's taken up by the front oil pump. I fractured the flange off, rendering the oil pump inoperable. That was an expensive mistake. New old stock oil pump later (very lucky find) and everything is reinstalled and the lash taken up.


Final torque of everything internal!


I took the governor apart- the large weight (towards camera) was free to move. That operates the reverse interlock. The smaller weight opposite it was sticky and would get hung up in the bottom of its bore. This was result of it chattering on the metal and wearing a ridge which it would get stuck in. I looked at the clearance, gently filed the lip off and then with some metal polish spun the valve up in the remains of the lip. That wore away enough material to make the operation smooth again.


Fitted the large modular pieces back in.

I then dismantled and fully cleaned the valve block. No pictures because it was fiddly and my fingers were covered in oil and gasoline. It's not overly complex but it is all spring loaded! Thoroughly flushed out and all pistons and shuttles operated to ensure smooth operation- the manual states they're good if you upend the block and they slide out under their own weight.


Everything else bolted on and all pipes in place.


Not to forget to fit a new O-ring to the pressure regulator. This is important to prevent leaks between the upper and lower portions of the valve (8-cyl version specific).

Phil

 

Finally, band preload adjustment. The manual states the "off the car" adjustment to be the best. First, the secondary band servo needs to be set measured 5 7/16" from the back of the servo housing.


An easy adjustment to make.


Bang on, accounting for parallax using carefully calibrated eyeball.


Locked down snug and checked again.

The front servo, being of a different design requires the preload to be applied differently.


The bung (arrowed) comes out, through the home the base of the piston is visible. The piston needs to be pushed in by a fraction of an inch and the preload set against that.


The hole the bung goes into is threaded blind to prevent it from leaking, so in order to be able to push against the piston, a threaded insert is required. I bought a compression fitting and a bolt. I tapped a thread down through the brass fitting (which is why brass is recommended, it's nice and easy to work with).


The base of the bolt was rough from where it was created. I filed it into a gentle dome and polished it smooth so it wouldn't dig into the alloy piston and create any metal shavings.

I fitted all new gaskets and gave the case a coat of paint.


That included the data plate, coded green to denote an 8-cylinder variant (compared to blue for a 6-cyl). I fixed the fluid coupling back on, cleaned up the engine flywheel and bolted it all back together.


Much better.

Phil

 

Hard freeze a-comin'. No anti-freeze? Drain that water!

Phil

 

Good job! The old poncho will go a long time again!

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That reassembly sure went fast! I was enjoying the ride along. Your engine and trans look great, good job.

 

good thought on the draining. 7 degrees here this morning. Sending lots of northern luv your way

 

Wow Phil! I'm amazed at the in-depth work your doing. And thankful there are still people knowledgeable and willing to tackle such projects as this transmission. Keep us posted

 

Rolling back in time again, while I had the engine and transmission out and access was good I decided to tidy up the firewall a little. I didn't really want to lose the ghostly paint code but the metal was going rusty, so it all got buzzed back to clean steel.


Turns out the chinagraph pencil has etched itself into the metal, so underneath, it's still there.


Little bit(*) of rubbing back, prep, rust coating, etch primer, paint, rubberized underseal and paint again.
*Actually a lot


Got the frame all sanded down, painted, undersealed and painted again- the underseal used originally appears to be the same rubberized tarry stuff but that dries poopoo brown. Can said it could be painted over, so black it went.


At the same time I redid the wiring. Connector blocks were old pressboard and had fallen to pieces.


I found some brown plastic that matches the original and put the terminals on it.


All new wires, loomed up to the lights.


More wiring spaghetti. Running everything through the original fuse box and keeping to the original wiring plan.


I made a few exceptions- I built the loom to be unpluggable for the dash gauges, simply because access is easier than having to blindly push all the bulbs back in.

I loomed up all the lighting wires in the engine compartment. I bought some nice self adhesive black fabric looming tape which looks and lasts much better than vinyl tape in places like this. It's also a lot easier to work with.


Rewired the heater fan switch and gave all the brightwork a clean.


Quite happy with that. Even reinstated the original dimmer in the headlight switch for the dash lighting. That got the gas gauge working which was a nice thing too.


Then some itty bitty things. The dome light would come on if I gave the switch a wiggle but it was unreliable. So, I pulled the switch apart, cleaned and readjusted it. That made the dome light work but the switch on the dome light didn't do a whole lot.


I bent the retaining lugs up and took the switch apart. Being up in the roof it is subject to condensation, and over the years the contacts had corroded.


As a result, the switch had become too hot and the spring loaded contact no longer moved nor made contact with the board. I prised it apart carefully and sanded, filled and cut it back into shape. Now the switch operates the dome light again. Just a shame the cover is missing.


It was right around then that I put the engine back in. That was a nice milestone.

Phil

 

Oh, and 12 Volt conversion. I would love to get my hands on one of those alternators mounted inside a case that looks like the original dynamo generator, but they are expeeeeeeeeensive so I decided to retain the alternator that came with the car. It's a Delco 10SI, originally 40 Amp, rebuilt to 63 Amp.



Whoever had implemented the thing in the first place did a right hack job. On the bottom is the lower mount, which provides support, torsional rigidity and a hinge point to allow for adjustment.
The other side has a thin piece of casting with a hole through to hold it at a hinged point and keep the belt tension.

Well, they'd mounted it upside down with the tension hole bolted loosely to the original generator front mount point and the base bolted in roughly with the adjustment bracket all bent up to try and get it in line.

It wasn't in line. It wouldn't adjust and the belt would squeal like a banshee. Doesn't help that it's the wrong belt, either.

So, I built a bracket to correctly mount it to the original generator points, keep it all perfectly in line and be correctly adjustable.


It started as a bunch of bent steel.


I started drilling out holes to mount the alternator to, and the pieces to it, with the holes slightly elongated to allow for final adjustment.


Mounted up tidily.


All properly in line and that'll accept a replacement if required. The alternator itself isn't really putting out, turns out part of the diode pack is bad. I need to order a replacement.

It's a decent conversion- it should charge at idle (generator does not) and does away with the regulator box as this one is internally regulated.

Phil

 

I had to put in my learning hat- simple things but I hadn't ever taken the time to find out how an alternator actually works.

The Delco 10SI is a fairly straightforward, run-of-the-mill internally regulated alternator. I can see why it's favored, it's a well designed, compact unit. I tested mine and it was just about putting out some voltage (went from 12.4V to 13.2V when revving the engine) but not the correct 14.4 and certainly not at low RPM. The no-charge light also wouldn't go off.

So, apart it came.



The end consists of a few modular pieces. Bottom left, the voltage regulator.
The orange piece is named "The Diode Trio".
The black and silver finned part is the bridge rectifier.
The round can is a capacitor.


Snagged from the Delco manual above, how is all connected up.

So, moving a conductor though a magnetic field so it experiences varying magnetic flux will generate an electric current in the conductor. The alternator has a set of windings (the conductor) and a rotating magnetic field created by passing an electric current through a conductor (field).
The alternator increases and decreases the current passing through the field winding to increase or decrease the amount of magnetic flux the stator winding experiences. This will increase or decrease the output voltage. The output is 3-phase AC, so is passed through the bridge rectifier to turn it into DC. The capacitor is there to absorb any stray spikes of voltage or high frequency noise.

The output of the stator is also brought out through 3 diodes to make half-wave DC and that is fed into the voltage regulator to allow it to determine how much the alternator is putting out. It also has a sense wire that's connected to the battery to determine the difference between the output and the battery (and it will increase it decrease the current in the field accordingly) to ensure it floats to 14.4V under all running conditions.

Well, the diode trio went bad. So only a little bit of the voltage the field was generating was making it to the regulator and so it was not raising the voltage in the field to create the correct output voltage.

I went to Napa Auto Parts and they said they'd sell me an entire alternator, nobody repairs them any more and nobody stocks the internal parts.

They list the part for $13 online so I'll order one and hope the voltage regulator isn't bad. If it is, I can change that too.

Don't like this discard-and-replace world we now live in.

Phil

 

Tried to cheer up one of the tail lenses. Both are all sun-crazed. Not perfect but it's a reasonable ten-footer.

Phil

 

There’s a local shop here that rebuilds starters and alternators. I haven’t been there in a while, but they used to sell parts too. That was especially helpful when I was young and poor and needed $5 worth of parts to fix the starter in my truck.




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great job on the transmission. thanks for the step by step pictures.

 

Phil , thank you for sharing your journey in renewing your Pontiac . May you and your Family enjoy many miles making memories.

 

All those little shops have all but gone from around here.

If nothing else, I was pleasantly surprised that Delco provide a comprehensive service manual for all but their most modern computerized alternators, free of charge. It's not like a 40 year old voltage regulator's inner workings are some huge trade secret any more.

I wish more companies would open up their archives like that, where they've made their money on it and the remaining interested parties are hobbyists and renovators and people who still enjoy fixing things and doing it right.

Phil

 

I figure, who knows. Maybe someone in the future can't find a full copy of the manual, or someone who is thinking about overhauling one but doesn't know if they should start might find it useful.

If nothing else getting a bit of a look inside a gearbox is something a bit different because not everybody wants to pull one apart just to eyeball the insides.

Phil

 

Welcome, and thanks. I hope so too.

Got a little way to go yet. I know some of this is very humdrum but like many folks on here, this is just a diary of a guy in his garage tinkering! So far there just been lots of little things to do. It'll get there.

Phil

 

I think you can get all the parts here.

https://alternatorparts.com/

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Phil, would you be so kind as to tell us how you "cheered up" the tail light lens. It looks good enough for what I and many others would like, a nice driver!

 

Just a little bit of industry light and magic.

https://www.tamiyausa.com/shop/spray-ts-plastics/ts-74-clear-red/

Clear red lacquer. Despite saying it is for plastics, it adheres well to metal too.



Polishes up nicely, that on the wheel trim was straight out of the can before it had time to fully harden. It also brings back a little red to the lens, mine have faded badly and are orange-ish-white.

--Phil

 

Here's a snippet of the project that went on hold. The car had the option checked because the cutout was there and the wiring was.. kinda there for a radio. The antenna was gone (since replaced with a new electric antenna) and the radio that was in the car was that horrible modern one that looked more fitting to be in a '77 Trans Am than in a 50's boat.

So, I started digging about on eBay for an original radio with the correct knobs. There are a number of trim levels for the knobs on the Chieftain, and mine has the chromed outer with black center insert.


This is what eBay turned up- internally looks to have been untouched for a long while but probably sat in a car for years or in a barn somewhere because the rust had set in and the chrome was horrible. Thankfully the bezel was still present in my car and was in much better shape.


I took it to bits and cleaned up the front panel to see how it would come up. Looks okay.


Certainly presentable when all reassembled. You really can't see much of it behind the speaker grille but hey. The big rubber funnel that goes between there and the dash to direct the sound is missing but I can make something up for that without too much trouble, high density foam.

Now, this is still a 6 Volt radio. I was thinking about what I had wanted to do with it- gut it and fit something modern inside or rebuild it and convert it to 12 Volt operation. I studied the schematic and decided that it is actually really not a bad design (way to go Sylvania), with a power output stage of about 4 Watts class AB1 which is very similar in design to some early Fender guitar amps.


Inside it was fairly clean but the tuning showed some problems. You can see there that the tuning rack (three circles on the rectangular brown board) is all bent looking.


Sure enough, the tuner body has zinc pest. That's a crystalline breakdown of the metal due to lead impurities in the alloy. Anyone who collects old die-cast models will know and fear it. The metal swells up then breaks off like grandmother's finest crumbly pie crust (except this is less tasty).


Cue Radio Number Two. A late 50's Buick "Sonomatic" set, which is basically the same barring the AF stage and oh, one important part, it's 12 Volt. However, it's built all upside-down so won't just transplant in and work. So, from the two will come FrankenRadio.


I stripped the tuner out of the Chieftain set and replaced it with the (identical) Sonomatic.


That fixed the tuner and mechanical parts... and it just leaves me with a full rebuild- the power transformer from the Sonomatic fits in neatly to the Chieftain.. then it just needs the 12V versions of the vacuum tubes and one last tidbit- I'm going to put auto-switching Bluetooth inside it. Switch it on and it'll crackle into life and play whatever it picks up on the antenna,but turn the Bluetooth radio on in my phone, and it'll click over to that input and the original audio amplifier in the radio will play the output of whatever my phone has stored or streamed.
Want the 50's sound but nobody's playing any music you like? Sounds like a plan to me.

That's on the bench still but I'm hoping to get that finished by maybe March, April or so.

--Phil

 

Is there any car part that intimidates you? Looks like you like a challenge.

 

Very cool save on the radio (with upgrade no less). Like so many other parts and pieces on this car. I’m really enjoying following this thread!

 

Rust.

I do not like rust.

Unfortunately this one has some. Y'all probably noticed I've been purposely avoiding it so far.

Phil

 

I was chasing some running problems and one thing that was an issue was the thing wasn't making a good seal against the block. One problem with the design is it's almost as long as the USS Nimitz, the other is the front end is always in the cool blast of air from the radiator fan, the other end is shielded and remains hot. As such, a warp has set in on the hot end.

It was suggested that I split the intake from the exhaust because they will twist and sometimes the warp can be adjusted out that way. Naturally, even with the application of propane torch the sheer mass of metal absorbed the heat and all four bolts sheared off.


Two I managed to drill centrally and remove the remnants of the bolts.


The other two the side of the manifold got in the way and I managed to drill them off center. I ended up having to drill them oversize and re-tap the holes.


That didn't work so I decided I would cut my losses and attempt to bring it down flat. It was all well off true.


Not perfect but better. I will need to double gasket the center two exhaust ports. Really I need to get it decked on a machine but there's nowhere I've found around here that I trust to do it.

Slight improvement but I need to order the correct thick gaskets for it.

Phil

 

Somehow I was expecting something like krytonite.

 

A question, to the knowledgeable- has anyone tried re-calibrating one of these speedometers?

I have a little GPS doohickey on my phone and it gives me an accurate reading of speed. The speedo is... rather optimistic, to say the least- at 15 mph it's telling me I'm hurtling down the street at 22. I'm used to a bit of error but this is a bit much. Feels like the spring has slipped or gone all kinds of funny.

--Phil

 

Apparently the exhaust manifold problem was common to straight eights I've seen a lot of broken Manifolds for the Buicks while junkyard prowling for a good one.