avgwarhawk

Dynaflow Tips, Trick and Problem Resolutions

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Good afternoon all!  I spent a few days investigating and studying the Dynaflow.  In particular, issues with slipping, leaks, whining and rumbling noises.  Basically making notes of what a happy healthy Dynflow performs and how a sickly Dynaflow does not perform.    By and large the threads on the forums I read did not come to a conclusion  as to what the issue was and the resolution.    I would like to start this thread in hopes those that that that have experienced Dynaflow issues and resolutions would share.  Also,   in hopes the thread  is sticked  becoming a page full of answers to trials and tribulations with the Dynaflow.  It can be a one source thread for the mysterious and foreboding(as some called it in my investigating) transmission affectionately known as the Dynaflow.        

 

For me, I performed a transmission service per the manual instructions.   Drain the pan. Pull the pan. Clean the screen.  New gasket.  Re-install.  Drained the TC.  One trick I noted on the TC, loosen one drain plug just enough to allow air into the TC. Prevents fluid from coming out but allows air in.     Spin the TC ( used a pry bar and turned the TC carefully) to the second drain plug.  Completely removed this plug allowing the fluid to drain as air was sucked into to the plug only loosened.  The converter holds a lot of transmission fluid.  It appears to have a drinking problem.  I used Dexon 3 with Mercon. 

 

Knock on wood that my Dynaflow is working well and hopefully for a long time.  However, if need be I can come to this thread, along with others, when trouble rears it's ugly head! 

 

Thanks!          

Edited by avgwarhawk (see edit history)
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Hello I have a 49 Super with Dynaflow, Mine was leaking at the torque converter,had been apart sometime in the past,replaced all of the bolts with nylon inserted lock type.Found a number of the original bolts were cracked along the slots on them , allowing them to back off.Dynaflow apparently leaked when fairly new,In the program service bulletins condensed book over half of it refer to The Dynaflow .Buick said that unless it was leaking more than a pint of fluid in a 1000 miles ,that was considered normal. It seems to work ok after that but still get a slight amount of leakage noticedable on garage floor.

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Chris, you give good instructions for draining the TC. Is there any trick to properly refilling it?

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57 minutes ago, mp67riv said:

Chris, you give good instructions for draining the TC. Is there any trick to properly refilling it?

No tricks.  However, in my case I pulled the pan, cleaned, reinstalled and filled until it registered full on the stick after running at operating temp.  Basically adding 3 qts and pulling the dipstick. Adding more until full at operating temp.  I then drained the TC.  Once drained and plugs secured I started with 3 quarts.  Started the engine to see if the TC would engage.  It did not. I added 2 more quarts.  Attempted to see if the TC would engage with the additional 2 quarts. It did in fine fashion. Reverse engaged as well.  Fluid now registered on the dipstick. Added 1 additional quart and test driven.  Pulled the stick upon returning to my garage.  Dipstick indicated full.  Job done.  Always keep checking the level and add as needed.  It is always easier to add than draining a overfill.  

 

Some may say both pan and TC should be drained all at once.  I'm a cautious fellow and work methodically.  Drain the pan. Assure the trans still pulls. Then drain the TC. Call me crazy. 

Edited by avgwarhawk (see edit history)
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Not a trick or anything but a question.. Mine has a drip from the accumulator on the driver side.. I'd like to address the drip but my question is if I unscrew that cover what will come falling out and how much fluid will come out??

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53 minutes ago, 1956322 said:

Not a trick or anything but a question.. Mine has a drip from the accumulator on the driver side.. I'd like to address the drip but my question is if I unscrew that cover what will come falling out and how much fluid will come out??

Don't take anything apart without reading and understanding the service manual!!  To answer your question, yes there is a big ol' spring in there and it is a "beach" to get the cap back on.  Most of the leaks are around the shaft for the switch pitch control.  The service manual calls the cap around the shaft a bearing and there is a little lip seal that does not even come in a rebuild kit that by now is crusty and useless.  You will have source your seal using the bore and shaft size...

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2 hours ago, old-tank said:

Don't take anything apart without reading and understanding the service manual!!  To answer your question, yes there is a big ol' spring in there and it is a "beach" to get the cap back on.  Most of the leaks are around the shaft for the switch pitch control.  The service manual calls the cap around the shaft a bearing and there is a little lip seal that does not even come in a rebuild kit that by now is crusty and useless.  You will have source your seal using the bore and shaft size...

 

Good to know!

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So how strong is the spring.. Love to address that leak but not if it's going to be a big big beach to get back in.. Living at an apartment sucks at times

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13 hours ago, 1956322 said:

So how strong is the spring.. Love to address that leak but not if it's going to be a big big beach to get back in.. Living at an apartment sucks at times

Any cap that needs to be screwed on against spring pressure is a chore.  This is not so bad with the tranny on a work bench upside down.  It is doable, but  warn the neighbors to protect their children's' delicate ears first ;).

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Any time a dynaflow performance issue comes up, I recommend doing the pressure tests as outline in the service manual.

Forum member Mudbone posted a bench test video which can be done installed in the car:  HERE

More dynaflow repair videos HERE

 

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5 minutes ago, old-tank said:

Any time a dynaflow performance issue comes up, I recommend doing the pressure tests as outline in the service manual.

Forum member Mudbone posted a bench test video which can be done installed in the car:  HERE

More dynaflow repair videos HERE

 

 

Great videos!  Thanks for getting the links together! 

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I have a   different problem with my 48 70 series and some one may be able to offer some ideas  , when I pulled the torque converter down it had a fairly heavy composition type gasket on the converter cover but the kit and subsequent gaskets I have purchased have bee thin paper and have just had to pull it all apart again because it does not seal properly .       Can any one make a suggestion ??

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Hello ,you may have to make a thicker gasket yourself,some of the after market parts leave something to be desired.Also check both parts for warping,and torque it down per shop manual . A I mentioned it a earlier post replace the nuts holding it together, The locking type nuts were only intended to be used once,Maybe you will luck out like I did and find loose nuts to be the problem. Good luck.

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