57 Dynaflow major slippage in all gears

[Smartin]

This is a fresh rebuild, and before I rip it out of the car to have my local shop check it out, I wanted to ask the forum to see if I missed anything.

 

Fluid is topped off full with engine running.  When shifted into any gear, the trans does nothing...unless I rev the engine.  After 5 seconds of higher RPM, it feels like it wants to go into gear, but won't really move the car except for a bit of rocking.  So it feels like it wants to move, but only lurches the car a couple inches.  This happens in all gears. 

 

I checked the linkage and all seems fine.  The last thing I want to do is pull the trans, so I'm trying to exhaust all other avenues first.

[TexasJohn55]

Front pump destroyed on start-up?  Got to get a guage on it.

[Smartin]

It's possible?  There was fluid in the trans, so I  know it was not dry.

 

Where would I hook up a pressure gauge?

[old-tank]

35 minutes ago, Smartin said:

Where would I hook up a pressure gauge?

Service manual should give you the port(s).

Not a 57 but THIS  may help.

[Smartin]

Thanks...forgot about Mud's trans video.  Need to get me a 200psi gauge

[TexasJohn55]

1 hour ago, Smartin said:

It's possible?  There was fluid in the trans, so I  know it was not dry.

 

IF...... The converter was not indexed properly initially when installed, it is possible to capture the gear, grind in and then pop into the mating slot after running.  It would not have had free play when bolted to the engine initially but may have now, you would have to unbolt from flexplate and slide it back and forth to check it before pulling the trans.  The 55 has a retaining bolt to hold it in place and it CAN be installed incorrectly but bolted up. Then it will bind and grind upon install and cranking up.  Don't know if the 57 has that retaining bolt feature.    John

 

PS: Don't take all that as "Gospel" but going on my best recollection when I rebuilt mine.

Edited June 16, 2021 by TexasJohn55 (see edit history)

[buick man]

Adam: Let us know who rebuilt the Dyna so we don't send our there.  If it had been bench psi tested before tear down and after rebuild and install, issues could of been corrected then.  But many who rebuild these today are gooey gasket artists not spec techs.

[Smartin]

It was done by a place in MN called Bobs Transmission Midwest I think….I just dumped all the pieces into Jim Hughes’ truck here in Auburn yesterday. He’s going to make it whole again.  
 

My local shop tore it apart and found metal in the fluid.  Wiped out front pump and some other not so pretty things.

 

 

[dei]

Good to hear Jim is getting to look at it Adam.

Sounds like he is well and keeping us Dynaflow guys in good good shape!

I have been nothing but pleased with the work he did on the transmission for my Special.

Wish there was a guarantee this trade was going to be taught moving forward. 

[lancemb]

On 7/3/2021 at 8:20 AM, dei said:

Good to hear Jim is getting to look at it Adam.

Sounds like he is well and keeping us Dynaflow guys in good good shape!

I have been nothing but pleased with the work he did on the transmission for my Special.

Wish there was a guarantee this trade was going to be taught moving forward. 

If he was local to me I'd take on an apprenticeship!