1950 dynaflow leak!

[Guest cdavescar]

Hello, I have been restoring my 1950 Buick Super 56r 2dr HT for approx 4 and a half yrs now and thought I was near completion, Only to find a couple of weeks ago that after starting the car up and running for a little while that I have a pretty bad leak from the transmission. The unit had been overhauled a couple of years back and since spotting the leak has been looked at and it is still exactly the same, I have put new seals in etc and was wondering if anyone may have any ideas what could be wrong. The gearbox has been in and out about 3 times with work being done on it each time but still the leak persists. any suggestions/advice welcome!!! Thanks for reading

Mr Carr (England)

[JohnD1956]

Mr. Carr, I don't want to be rude, but you have not given us much to work with. We need some detail. Standard shift or Dynaflow? Leaking from the front, rear or one side more than the other? Leaking while running or after sitting a while ( how long it has been sitting may be important). Have you tightened transmission pan bolts to proper torque, or over tightened them, leading to warped pan and misaligned gasket? Is it the transmission oil cooler or the cooler lines that need to be tightened? What level of fluid is there on the dipstick after the engine has been brought to operating temperature?

Please help us to help you. Pictures would be helpful if you have any.

[60FlatTop]

Keep an eye on the fluid level so you don't run low and drive the car around some. Nothing makes the rubber seals in a Dynaflow happier than hot fluid. They will swell up and work well with use.

I had a Dynaflow that would run drip free as long as you drove it every day. If it sat for a week you had to add a quart.

Bernie

[d2_willys]

Mr. Carr, I don't want to be rude, but you have not given us much to work with. We need some detail. Standard shift or Dynaflow? Leaking from the front, rear or one side more than the other? Leaking while running or after sitting a while ( how long it has been sitting may be important). Have you tightened transmission pan bolts to proper torque, or over tightened them, leading to warped pan and misaligned gasket? Is it the transmission oil cooler or the cooler lines that need to be tightened? What level of fluid is there on the dipstick after the engine has been brought to operating temperature?

Please help us to help you. Pictures would be helpful if you have any.

Agreed, more info needed! I can be a wise guy and say reseal it again, but I am here to help, not be snide.

And from what I have read about Dynaflows, they are notorious leakers if not run regularly. Why, I have no idea. I do know that my Flight pitch dynaflow leaks if not run too, so it may be something to do with the converter anti drain back valve not working, or the torque tube seals, as both Flight pitch and variable pitch dynaflows use the same setup.

[JohnD1956]

I must edit my post above. Obviously this is a dynaflow car. I just missed that last night.

[michaelmis]

http://forums.aaca.org/f115/help-needed-1950-buick-special-transmission-246064.html

Mike M Perth

http://buicknet.com/index.php

Edited May 8, 2012 by michaelmis (see edit history)

[Guest cdavescar]

Hello JOHND

Have just put the dynaflow transmission back in after totally rebuilding the transmission again.It does not leak when standing,i can start the car up and does not leak on tickover,but as soon as you locate drive the torque converter starts to leak from the front oil seal in primary pump.

It was first fitted with a front oil pump and convertor by a gearbox specialist but have had the leak since.I have had it back to him +he cant find any problems.

I

have checked the alingment on the convertor +it is ok .It is a very bad leak

Hope that this is enough info for you.Regards David Carr

[Glassesguy]

I don't know where you are located, but a phone call to Jim Hughes of Jim's Dynaflow Service in Perrysburg, Ohio may be of some help. He rebuilds all Dynaflows and is very knowledgeable on the problems and the updates that were done. I learned from him yesterday that many of the supposed total rebuild kits do not always include every seal or O ring necessary to do the job. His # is 419-874-2393.

[JohnD1956]

Reading my 56's manual I see two possibilities. #1 the Pump cover was supposed to be tightened in a prescribed sequence, which crisscrosses the face of the converter. If that wasn't done then #2 may be that the pump cover is now bent, even a miniscule amount, which may not be visible to the naked eye, but enough that when you start to rev the engine the increased pressure in the trans finds the opening.

One other thing I'd be concerned about, although this is pure conjecture on my part, is, do you have the right Pump/ Torque converter?

The thread about the 55 Dynaflow was an eye opener for me when I learned that 54 - 56 Dynaflow mechanicals are not directly interchangeable. Such may be the case with your 50 Dynaflow and perhaps you have some incorrect parts with different tolerances leading to the leaks?

Note: I am not an expert in this area, and it would be incorrect to assume I am right about any one or more of these things. I just offer this as areas to check when all else seems correct.

[Guest cdavescar]

Hi guys and THANK YOU for your thoughts/replies. I am looking into all of these and will try and keep alll informed. Thanks Again Mr D Carr