Trans fluid
That being said.... My rebuilt 2001 Fbody T56 from a few years ago with new bearings, carbon blockers, steel shift fork, bronze fork pads, new synchros..... has never shifted as good as the new T56 Magnum I'm running now. The Magnum may cost more.... but man does it shift nicely. I really love this transmission. Better shifting than a GTO T56 also.
When did ZF ever manufacture the T56?!?!
Or are you speaking of the C4's ZF six speed gearbox??







