The 904 lock-up in my 84 van has a hard time getting moving. It seems that once it's up to speed (shifts into second, third, and lock-up) she's fine. She also has a tendency to stall the engine when slowing down for a hard turn or at red light.

About 18 months ago I rebuilt the trans with all new seals, rings, clutches, yada-yada. Everything worked fine on install.

A few months back my son (the van is his daily driver) enlightened me about the problem of not being able to launch quickly, as it had in the past. I changed the filter and the black fluid. A week later I changed the filter and fluid again (it was still black in color). A third weekend later, a new filter and fluid change, the fluid black again.

Searching through the post here, I seen a thread about stators inside the TC locking up, causing a stalling issue. But there was no mention of a black-colored fluid.

What I'm looking for is a step-by-step troubleshooting guide to either make sure it's just the convertor or if replacing that will not rid me of my problem. I have a spare 904 on the bench right now that needs only the reverse band replaced.

FYI, both bands are adjusted correctly, the kickdown linkage is adjusted correctly, the correct fluid has been installed. The "lean-burn" conversion Holley 1920 was replaced with the original 1945 to eliminate the stalling issue.

Any help is appreciated.


Troy

Any factory service manual will have detailed pressure check instructions.
My guess is that the main clutch pack is slipping.
DD