Projects Mild custom '51 Pontiac Chieftain

Who needs Rudolf when you have "The Chief" in the lead ....... Ho Ho Ho and away we go !

 

Forecast says 24F next week.

I guess I need to plug up the leaking manifold stud and put in some antifreeze.

 

Took the manifolds off.

Had to heat the stud to get the nut off; Re***embled and now I have a misfire. Vacuum gauge is very steady so further investigation ensues. Idle mix changes the speed of the engine so it's not a blocked circuit there- might pull the carb off again and clean it out anyway.

But, the manifold no longer leaks coolant and I changed the pressure switch for the oil idiot light while I had access.

Phil

 

Found the problem. Manifold gasket isn't making a good seal on cylinders 5 & 6.

Apart it has to come, again.

 

Engine in pieces again.

RTV in place. Running again.

Making clouds today, it's chilly.

Definitely running better, it'll idle ~75-100 RPM now.

Next, find the intermittent connection in the ignition circuit.

 

You’re good!

 

75-100 rpm? Damn that's low! Do you have oil pressure there?

Devin

 

Sure do, even enough to keep the light off. About 20psi, which is in the "yup" range.

Generator wasn't chargin' though.

 

Well, ain't had much to post. Just been driving the car, really. Noticed one thing about the gear changes, it would never get hung up if I didn't take my foot totally off the gas.

So, jacked the car up and set the throttle arm to be a fraction off the stop when the throttle is at minimum.

It appears to have helped, I'll see how it behaves in a few minutes after having been parked half an hour, hot.

Phil

 

...nope. Back to the drawing board.

 

Fixed the trunk lock, which conveniently didn't want to unlock the trunk. The bar between the lock and latch had twisted slightly and wasn't sitting in the lock properly. Hammered a piece of steel pipe over the end and filed it down to fit. That works nicely now.


Again, the same story. Gearbox in pieces.

Today, taken apart more than usual, to pull the governor out for inspection and cleaning.

Not too bad. Cleaned up thoroughly and re***embled.

...aaaand all back together again.

Works nicely cold. Still the same story hot. Ugh.

Phil

 

I'm sat here looking at this picture from yesterday.


You can see the contact patch the valve block makes on the side of the gearbox housing.

Using this from the manual, the various drillings can be identified.
It looks like the patch by "G-1 to 4-3 valve" is not making good contact between it and "Compensator to front and rear servos". If that's warping when it's hot (body is cast iron, valve is aluminum, so totally possible) then if the governor pressure is leaking to the compensator circuit with the compensator valve closed... I'm trying to think what effect that would have.

Either way that's making me want to make up a gasket to better seal the valve block. Thoughts?

 

Take a piece of gl*** and some 400 grit wet or dry and some ATF and surface the aluminum block. At it's age, it may well be a little warped. You will be able to tell after a few strokes on the sand paper.

 

It's not the valve block, I think the iron surface of the gearbox isn't flat any more.


I made a gasket. Hopefully it's not too thick.

Phil

 

Wow, bet you just whipped that gasket right out in about 2 minutes Phil! Great job.

 

Nice work. I don't see why it won't work.

 

That is GR8 work! Phil can fix anything We've all seen it.....

 

"Fix". This is still proving to be a bit elusive.


Sadly, I know exactly the tools required for this job.


Regardless, that got fitted and a test drive shows it still does the same thing but a lot less often.

This Dexron oil seems to be between 5 and 15 weight, which is too light for the gearbox (takes 20 weight oil).

Any suggestions on hydraulic oil that would be suitable that's a heavier weight?

 

Well, you refuse to try ih hy-tran fluid.
So, maybe just try regular motor oil?
Those early hydramatics did use motor oil..

 

You got a straight edge or a ruler? Sorry, dont know right names but something that you can use to ferify those surfaces that they are warped or not.

 

Do like the factory recommended on TF trans... Add a quart of 30w oil.... Makes them shift crisp and clean.

 

Not so much refuse, as not able to find it cheaply enough.

I'll have to see if I can find it locally. These ones used Type A fluid which was heavier and goopier for sure.

Phil

 

Worth a try. I may drain this synthetic stuff out (was put in because it holds viscosity better over a wider range of temperatures) and try mineral ATF with a bit of engine oil in.

Phil

 

The gasket I used is meant for water pumps and such; it is a laminate and conpresses nicely so any inconsistent surface will be sealed by it correctly.

The witness marks show it was seating better in some places than others.

It did exactly the same thing with two different valve blocks, too.

 

How many quarts does it hold? Have you tried the Ford ATF?

 

3.3 gallons! (I gave up measuring it in quarts after about 8 went in and it still wanted more)

The manufacturer of the friction material I bought said don't use Type F. So, that's off the list.

 

In the Military M-211 GMC 2&1/2 trucks with Hydromatic they used 30 weight non-detergent motor oil you may want to google it and see for your self.

 

I was going by the manual I have; it quotes that if you run low, top up with high quality 20W engine oil and then flush and refill with the correct type once you've reached destination.

I could see 30W engine oil working though.

 

That did lead to TO-4 30W hydraulic oil, which Allison OK for their transmissions. Can't be all that bad...

 

Find tractor transmission oil that is wet brake compatible, choose right wiscosity and try.
F type will not do harm.just get you firmer shifts.