KDD

98 camaro. Going down the road in od and the car starts to slip. I can down shift, then go back to od and it will be fine for a while. I can drive around town in od and it will not slip at all. help!!!

mrvedit

Wear/slipping/failure of the 3/4 clutch is probably the most common problem with the 4L60E, especially older ones. It will quickly get worse so start saving for a rebuild.

If you have a local shop rebuild it, I recommend asking for a 4L65E rebuild kit; the primary difference is that it has a 7-friction 3/4 clutch instead of the wimpy 6-friction one. Probably cost $10 more. If you have added power to the engine, you might consider having a shift kit installed, or at least a larger boost valve.

KDD

That is what I was thinking. My camaro has 94,000 on it and it has been driven. I live in Peoria il and have not heared of a good local performance trans shop. I am going to check my input and output trans rpm to see if it is the trans or torque converter. One of the other posts had said that the oem valve body is known to have some problems.

mrvedit

The most significant valve body problem is related to TCC (Torque converter lockup clutch) problems; it often results in an 1870 code. There is no aftermarket valve body. Sonnax makes it fix which requires reaming out the TCC valve area and installing an oversized valve. Since performance oriented people don't need a soft TCC apply, the Transgo shift kit replaces this finicky (PWM) TCC valve with a simpler on-off one which doesn't need reaming. You can also get GM reconditioned ones (with GM oversized valves) and rebuilt ones on ebay with the Sonnax oversized valve.

Find a local GM-oriented auto club (or maybe even Ford) and ask who they recommend for a local trans builder. Some local trans builders do performance work on the side.
Or consider buying a performance trans from one of the sponsor here like Performabuilt, RPM or FLT.