97 Blazer Transmission Issues

I have a 97 Blazer with 131,000 miles on it. When I drive Over about 50 miles at interstate speeds it will shift very hard from first to second. After about 100 miles the check eng light comes on with the code trans slipping. It is like it does not want to shift from first to second and when it does it is very hard unless you feather the gas. During my normal everyday driving it normally shifts just fine. Everyonce in a while it may shift slightly harder than normal. It only does this from fist to second gear. I have searched on here but I am not sure what the problem is. If you let it cool off it shifts fine for a while but returns to the hard shifting when I am on road trips. Anyone have an idea here?

Ever serviced the tranny?

Ever serviced the tranny?


Yes it has been flushed and filter changed. It was doing the same thing before I had it done. It has been about 15k since then but the fluid is still good and does not smell burnt

You may have a defective ignition switch.

Prone to fail in the 1997 and will cause tranny problems.

Being that this is an issue that tends to occur after a warmup period, I would suspect that you probably have wear in the transmission valve body that is allowing excessive leakage/pressure loss when the fluid warms up and thins out significantly. There is a company called Sonnax that makes valve body repair parts, and their website has links to very good articles about some of the common failure modes of popular transmissions, including the GM 4L60E.

Thanks for the help and the link.

Being that this is an issue that tends to occur after a warmup period, I would suspect that you probably have wear in the transmission valve body that is allowing excessive leakage/pressure loss when the fluid warms up and thins out significantly. There is a company called Sonnax that makes valve body repair parts, and their website has links to very good articles about some of the common failure modes of popular transmissions, including the GM 4L60E.

That or you ust need to replace the fluid.