Alright tranny experts - what did I do wrong?

[taxx]

I rebuilt my C4 last winter. Just finished the EFI swap and finally got a chance to drive it. I put in a 2200 - 2400 stall speed TC in there. I ended up losing the tranny in less than 50 miles. I will detail out the symptoms.

Initially it seemed great. Found one problem - when using the ratchet shifter to run through the gears it seemed to work. However if you were on it hard in low and runny fast and slammed it into two it would quickly send smoke out the breather hole and bind up on itself. Like it was trying to go forward and reverse at the same time??

Well I decided that was a screwup in the valve body not engaging and releasing bands and clutches as it should. Maybe thats not right.

So the other day I drive it a little further Shifts fine in D and compensates for how I am driving. I get going and when I hit the throttle it spits fluid out the breather. I get about 10 miles and start to get a whining noise. Doesn't sound good and is pissing more fluid. I decide to park it and let it cool for a few hours before I head home. On the way home I noticed if I goosed the throttle it would slip and sound like some gears grinding. But if I was gentle on the throttle it would go and accellerate slowly. About halfway home I got one last sound of gear grinding and a whole lot of fluid pissing all over the place and lost all my gears forward and reverse.

So I have a rebuilt C4 to stick back in there, that someone else rebuilt, I just need to swap output shafts since the rebuilt one is for a 2 wheel drive application. I pulled mine out tonight and pulled it apart expecting to find the pump was toasted. In the pictures below the ONLY thing I see is the black burnt fluid, the metal shavings in the fluid and that the forward clutchpack is pretty well toasted and worn for 50 miles.

Any ideas on what went wrong?

Any way to make sure my TC is ok to install with the new tranny?

would toasting the clutchpack have the effects I noticed (no gears, grinding noise)?

what would cause it to piss fluid out the breather? The breather is right above the governer. I am pretty sure it wasn't over filled and I would think it would need to be several quarts overfilled to splash fluid out the breather....?

pump gears are fine

Looks ok to me:

EWWWWW!

This got hot:

really groovy

all gone

 

[BUCKETOBOLTS]

Did you check the clearance on the clutch packs when you rebuilt it the first time? I like to run .005" per friction disk. The low/reverse band was not adjusted to tight? Did you check the end play?

P.S. I PMed you about those pics and files.

 

[taxx]

End play was ok. I checked the band a few times. Never checked the clutch pack clearances....

Looking forward to your file. Will help me understand this. Got another one to stick in for now while I rebuild this one and try to learn. I followed the Hayne's manual for rebuild and never saw anything to check clearances cept endplay.

 

[BUCKETOBOLTS]

I don't know where you bought your clutches, I bought mine locally and they gave me different thickness disks for the foward and direct clutches. It helped get my clearances right.

I'd say that the foward pack had too much clearance. I always stack the frictions and steel seperate to check clearance, then slip a feeler guage in between the steels near the snap ring. This just keeps from cutting up the frictions with the guage, don't ask how I found this out.

 

[taxx]

When I tore into this other one today I remember now having checked those clearances but that doesn't mean it was right.

Got it all back up there and just about ready to test now. The only thing I am remotely concerned about is the Torque Converter. I reused the one that was in there when the tranny went since it only had around 25 - 50 actual miles not 20k - 50k but 25 - 50. I cleaned it with mineral spirits dumping and flushing till it was clear. Then flushed it a few times with ATF. Ran a magnet around in it. It seemed fine. Seemed like it was ok but what if that was part of my orriginal problem? We will find out soon enough I guess.