This happened probably a couple years ago now in my first TH400. Went to backup out of a fairly level driveway and things started slipping. Driving down the road, 1st and 2nd were solid as ever but when going into 3rd it was slipping really bad so I drove in 2nd gear back to a friend's shop. Went to leave later that night and almost had to push the car backwards. Reverse did nothing after moving back 4 feet and 3rd was gone. The governor wasn't working either about a week prior and I had been shifting it manualy and driving normaly.

Any ideas on what it could be or what to look for when taking it apart? It was a cursed trans that gave me 6 months of hell but drove fine for 3 months before it gave up the ghost, behind my old 305 I might add. One of the things replaced was a center support shaft that was causing a pressure bleed through and making 1st gear and reverse to engauge at the same time. That was fixed and new clutches were put in. I'd like to get this thing fixed for a project car.

 

Reverse & 3rd gear use the same clutch pasck. When you rebuild the unit, make sure you add the Trans-Go Performance Shift kit. I carry everything for these units, let me know if I can be of help.

 

Tell me why my old TH400 with a transbrake has no reverse or transbrake. It originally worked fine but now it doesn't. The tranny doesn't need the transbrake engaged for reverse to work and it's a reverse pattern valve body. I've had it apart a few times trying to figure out what's wrong. The transbrake barely holds and reverse is almost non existant. All clearances are fine. I even tried a different case. I'm suspected a hydraulic leak somewhere.

I finally just installed a PG into the car and pushed the TH400 under a shelf in the garage. I'm happy now with the PG but I'd sure like to know what's wrong with the TH400.