1957 Hydro-Matic, Strato Flight, need help!!!

[alistheman]

OK, hello to you Cadillac owners! I am in need of someone that may have a higher level of expertice in diagnosing a problem in my 57 Hydromatic. First problem is, I didn't know the condition of the trans, except the previous owner had told me it was starting to give him problems, but wasen't "blown". So, I took a gamble on buying a 57 hydromatic factory manual, I took it apart and didn't see anything wrong except worn clutches and a broken spring washer in the rear. If it was a disaster i would have baught an adapter plate and put in a turbo 350, but seeing how it looked rebuildable I called Fatsco and purchased a master kit.      On I went rebuilding a hydromatic, I had to make some tools to do the job, but I got it all back together and back in the car, and the car slips in reverse, works in low, works in drive right, slips in drive left at a stop in the same way it slips in reverse. I Checked the fluid pressure from trans and it is in range with the factory manuals specks, in P, N, dr/l ,dr/r and low it reads about 106-108 psi, in reverse it burries the guage at 160 psi (as far as guage goes), and the manual sais 160-200 psi for reverse. So I took the pan down and took apart the valve body again, this time checking every diameter and length of spring and compared it to the manual and made sure, that spring went where it was. they were all correct. Cleaned everything with brake cleaner , blew it out with the compressor and put it back together. It was still the same old thing, didn't work. What now? Somebody out there have a clue about these things? I'm lost and going deeper into the woods. And so you all know, i forgot to mention up front that i own a Pontiac, but the trans is the same. It's still a GM. Any help, would be a help, thanks Al

[Roger Zimmermann]

Pontiac, Oldsmobile and Cadillac have the same transmission, except for some outside details.
I know these transmissions rather well; I overhauled maybe 15 of 20 of them.
I had once a problem with the reverse slipping: my error, I forgot to tighten the screws of the mamual vave body. If I had measure the pressure, I would certainly not have get so many psi as you are reading.
From the shop manual, I see that you may not have a reverse due to the front sprag clutch slipping. In D "left", the condition you are describing leads again to the front sprag.
Good luck!

[alistheman]

Hello Roger, I was hoping you would be one to reply to my post. How do you come to that conclusion, I read that manual and was trying to see what similarities the reverse and drive left functions have in common. Without having my book in front of me does the sprag hold in both dr/left and reverse? Not to mention that a sprag cost $92.00, and a gasket and outer seal kit is $60.00. I am not doughting you, i am just amazed you could see that in the manual. I found a n.o.s rear sprag and some pump bushings in a box, so i might as well replace those too.

[Roger Zimmermann]

Yesterday I got a new computer, the old one was 5 years old, time to let retire it. Consequence: my scanner does not work anymore, I have to buy another one. Therefore, I cannot scan the page from the Cad shop manual; I'll do the old fashion by writing:

"slips in 1st & 3rd in DR-4": possible causes: Front spag clutch slipping or front sprag clutch broken

"No reverse drive-slips": possible causes: reverse piston apply restricted or leaking, low oil pressure, manual linkage misadjusted or Front spag clutch slipping or front sprag clutch broken

It is always difficult to make a diagnostic at a distance; it happens that I just saw these possible causes. You will have anyway to take the transmission apart and have a look at every part.
To tell the truth, I never saw a front or rear sprag slipping or broken, but 15 or 20 transmissions is a small number after all!

[alistheman]

thank you Roger

[J. Gomez]

This site should give more details on the Hydra-matic, it has the complete GM service manual.

http://oldcarmanualproject.com/manuals/trans/GMControlledCouplingTrans/Introduction/index.htm

Good luck..!

[Walter Youshock]

The front sprag broke in my '57 not long after I got the car.  I was taking the car to work one morning and came to a Stop sign 1/2 mile from the house.  Went to pull away and NOTHING.  Downshifted to 2 and nursed the car home.  The oldest trans shop in the area told me it was the front sprag and he was right!  He said they would just go without warning and the '56 was the worst  unit he worked on and that I should be happy I had the slightly better '57. 

[alistheman]

  Well , I did hydro-matic surgery, and I found out that I am a dope. Zimmerman, you are 100% correct it was the front sprag, but it wasen't broken....... it just installed it upside down!!! As soon as I took off the spirol snap ring and pulled the front sprag out, I said, " the shoulder is not up!" So when it was supposed to lock it was slipping and vice versa. I put it back together and ,Ta Da, it works! Thanks for your help ! I could have done it without you , but you saved me alot of time! LOL!!! I guess now rebuilding a turbo 350 will be like a walk in the park. You guys are awsome, and thank God for the internet, or was that thank Gore for the internet? anyway , PEACE OUT!!!!!!!!

[Roger Zimmermann]

Ah! These damn sprags...It so easy to put them upside down! I'm glad that my comments did help you. Also, thank you for the feed back!

[Rob Troxel]

This thread truly represents what our CLC alliance is all about!  Who hasn't been in the garage with something apart and wondering "why me" when something goes south.  Sharing our distress and then getting advice that solves the problem is worth a million.  Thanks again to all who contribute like Roger.

[alistheman]

I put the car down from the lift and backed it out of the garage and put it in drive/left and it went up the road and shifted!!!!!!!!!!! PROBLEM SOLVED....... Awsome!