Replacement Auto Transmission?
 

I need to either replace or have my transmission rebuilt this winter in my 89.

I’m seeing a lot of low mileage 700r4’s for sale but which ones will work?

Does it have to be out of a corvette or do you just replace the tail piece so you have the mount for the C-Beam?

It needs to be out of a Vette or get recon with a Vette kit. The valve body has some control parts that are specified "Corvette Only" that control shifting and how hard/soon shifts are made working with the TCC and TV cable.

There are multiple differences between the various years of 700r4s. The main thing to watch for is to get a '88 or later. They made many changes in late '87 to fix problems with earlier years.

The Corvette specific 700r4s have a large "V" molded into the side of the bell housing. The main differences are a special valve body (and corresponding case passages, called "worm tracks") and larger servo.

You can use a non Corvette transmission by swapping the tail shaft housing (you need the C beam mount). The output shaft is shorter on a Corvette, but you can cut off the end to make it compatible. You won't be happy with the result.

Take my advice, have your original rebuilt by someone that has a good reputation and do not replace it. There are many specialized internals in the Vette tranny, and if you get some other GM unit it might end up shifting like a truck. Ask me how I know...

Thanks, I was thinking the same thing. I’m not sure what’s wrong with mine it shifts just fine through the gears but when I hit passing gear the RPM’s go up but she don’t go. Very bad slip.

Not to mention the tailshaft housing and overall length is different to the corvette!!

I've got a passenger car 4l60e with a shift kit. 5/8" off the outputshaft, Corvette tailshaft housing. It works pretty well. :yesnod:

http://i539.photobucket.com/albums/f...o/11-28-10.jpg

My 700R4 out of a Truck it has thicker K case.
The inspection cover is cast aluminum the tail shaft been cut down 3/4 inch for the Vett tail housing shift kit works great for me.

I asked around before I replaced my stock 700r4 mainly it was rebuilt 4 times everytime it came back worse so I said enough is enough it's time for anouther trans.

I went with a performabuilt.
http://www.performabuilt.com/

No core I not pushings Meg HP but so far I glad I purchased this trans I had about 6 months now and 5000 issues free miles on it.

It can also be you're converter.

corvette and gmc syclone and typhoon had the best 700 r4 calibrations definally stick with a vette tranny

Have your original 1989 C4 trans rebuilt & blueprinted.

Find the best transmission man in your area with experience building 700R4 & 4L60 E transmissions.

Pete K is an excellent veteran auto transmission man here on C4.

I have had 100 % success rebuilding & blueprinting my own 87 vert 700R4 trans.

Either 1 of us can help with C4 auto trans tech.

Pete sold his own transmission rebuild hand picked kits & torque converters in the past.
He may still do so yet today.
have to ask him.

I sourced all my own parts needed piece by piece for my 700R4 trans.

BR