Ok some have said that the 87 back 700r tranny's are not as good as the newer ones I would like to know what makes the difference I have a 84 700r that has 193,000 miles on it before it died so what makes the newer ones so mcuh better. Any way I am rebuilding the 84 700r and would like to know what is recommended to make it better but in all honesty i have no complaints out of this tranny. Is the shift kits worth there time and money and what is the benefits and down sides

 

Well, you've got one of the "first" 700r4's, there... GM didn't have the design polished yet.

The main upgrade in 1987 was the fluid pump. Inside the 700r4's fluid pump is a circle with "vanes" cut into it. (Picture a pizza with gaps in between the slices.) Early (83-86) 700r4's had a regular distance between the vanes. This caused the pump to aerate, and run dry. The metal pump gear would then eat into the aluminum trans case. Shavings would go everywhere, and the trans would die.

GM redesigned the vanes to have both (1) a greater number, and (2) to have irregular spacing.

GM also added an auxiliary valve body in 1987. You know how, when the car is stuck in snow, you're supposed to put the car in drive, then reverse, then drive, etc to rock it out? Well 86-below trannies got the hell banged outta them. This aux valve body cushioned the shifts.

I believe GM also introduced a new design of accumlator piston that wouldn't leak.

You can retrofit most of these changes, except for the auxiliary valve body), into your '84 700r4. In fact I don't think you can -find- an early design fluid pump anywhere... and I don't think the old-style accumulator pistons are made.




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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards