After I rebuilt my 1987 700R4 transmission I went over 100 miles with no problems. After successfully backing it out my garage and driving several more miles I realized my reverse clutches were burnt up. I torn it down again and cleaned the case and value body, replaced gaskets, seals and reverse clutches and reassembled I then drove 50 to 60 miles, (which it shifted fine) and reverse clutches burned up again. Any suggestions?

 

The Reverse-Input Clutch Pack (Inside the Reverse-Input Drum) or the Low-Reverse Clutch Pack at the very back of the Transmission?

 

the Low-Reverse Clutch Pack at the very back of the Transmission]

 

Did you remove the Low-Reverse Piston from the very very back of the case, and replace the 3 big Seals that go on it?

 

Yes I did twice. I’ve rebuilt several 700R4 and had no problem with this before. When driving in the forward gears it seam fluid is causing the reverse clutches to slip and burn up. I checked the seals and clips all is ok and then this happens. Any suggestions?

 

Did you check the reverse clutch clearance ?

 

The 1987 Model Year THM700-R4s came in two versions:
-Early without Auxiliary Valve-Body.
-Late with Auxiliary Valve-Body.

The Check-Ball Locations and Separator-Plate differ between the Two Versions.

If you mixed-up the Separator-Plate or Check-Ball Locations, you could have a huge leak in the Low-Reverse Circuit, causing Clutch failure.

 

Yes

 

Yes what?

So do you have an Early or Late 1987 Model Year Transmission?

 

thank you for your reply that is exactly whats wrong.