Projects Mild custom '51 Pontiac Chieftain

Took it for a run. Result? Much improved; light throttle and acceleration it still hangs up a little.

I think the chamfer needs to be made a little softer, polished. At light throttle it seems as though there's only ounces of force available.

Put my foot down a little heavier and it shifts just fine. Happy with that overall.

Phil

 

The nuances of driving them is part of the charm of driving old cars.

 

Most guys would long ago have given up and slapped in a 350/350. Your patience and problem-solving methodology are to be commended. I daresay emulated.

 

Fingers crossed that’s the end of a long road with your box.

 

I hope so. Never would have thought it was a valve getting stuck halfway.

 

Wouldn't adjusting the throttle pressure linkage boost pressure a tad?

 

It would, but that also defeats the object of having the main line pressure reduction in the first place. Taking the edge off that piston so it moves correctly is a better solution in my opinion because it retains the low pressure at light acceleration and thus prevents the shifts from being harsh.

Phil

 

well--B+M won't hire you --but the pontiac dealer sure would!!--as all have said --great thought processing!

 

It shifts with quite the kick if you stamp on the loud pedal, not quite B&M smoke the tires into each gear harsh, but it lets you know it's changed!

 

Rolled over 115000 miles today. Did a couple moderate distance, high speed runs and although it did hang up a couple times now, every time snapping the throttle shut causes a 1-2 shift so it's just getting stuck on the edge again but now will free up easily.
I'll pull the valve block at some point and machine it more.

It's made it a lot easier to drive, without having to worry about it not shifting before the engine throws a rod.

Phil

 

You got spare valve body right?
Take that valve spool out and cut grooves all the way about 3mm space between.
That will center the spool as oil is not force it to one side.

 

I do, but I'm not sure that'll work because it's not a very long piece. I do have a spare though.
It's not the hydraulic pressure making it go to the side though, it's the spring.

 

Jumped at a rare opportunity, NOS valve block. Gives me a chance to see if machining a sleeve for the old ones is viable.

Phil

 

I'm still followin' ya Phil. Love this thread.

 

I'm surprised; all I've been doing is driving it and occasionally greasing and changing the oil.

 

I like that you are staying with the trans shifting problems, so I keep looking, Love it!

 

Your determination to make things right is admirable and rare. Most would have said it's good enough long ago.

Devin

 

I agree with everything being said. Knowledge lost for decades is being regained here. Because of the very nature of the internet, it will be retained this time.

 

Yep! and this is just how it should be. Driving it and using it is the best thing for it. Enjoy it.

 

Well, I know what the problem is, was going to try some engineering but the opportunity for one that doesn't need a repair came by.
So, that should make it more fun to drive.

Certainly easier for someone else to drive- you need to know the quirks right now and how to fix 'em as you drive.

Phil

 

Just think Phil..... You're gaining knowledge for a retirement gig as an early Hydro rebuild expert!

 

By then we'll all be flying around in those Jetsons looking cars, BRRRRIIIWWWWWWW

 

Tonight, the car was called into action, to be taxi. Fully loaded six-up, we drove into the sunset.

Handled that very well really!

 

Took the clock out because it had been losing time. It's been a few years since it was serviced last.

Stuck it on my bench and pulled it apart. Oiled the pinions and set about adjusting the hairspring balance.

Yup, I set my clock up with an oscilloscope. Nice even pulses there so that's good.

Ticking over smoothly again.

All back together, tested and ready to go back into the car.

Phil

 

Been sitting listening to it back in the car.

Doesn't seem to be catching the escapement any more (audible click) so that should be back keeping time properly again now.

Phil

 

Great job! As I remember it "back in da day" clocks were the first component/accessory to go ***s up in our cars. It was rare to find a five-year-old GM with a working timepiece.

 

It's about time you fixed your clock!

 

It gained about two minutes overnight so that's a good sign.
Need to go bring a small screwdriver out and dial it a touch towards S.

Phil

 

I can’t remember, did you have to repair your clock in the first place or did it just need cleaning?

 

It needed a thorough clean, adjustment and conversion to 12V.

Phil