I recently had my 46RE transmission completely bench rebuilt by a good rebuilder and I re-installed in the truck. After a short drive, the overdrive light on the switch comes on and very shortly thereafter, the trans temp light comes on. I've checked the fluid and it's full. Using a laser temperature gun, the pan is only showing a temperature of about 140 degrees and the cooler lines are cool to the touch near the radiator. I flushed the cooler lines well with LubeGuard before re-installing the transmission, in addition to blowing air through the lines. I did have the factory check valve installed in the return line, however, after I encountered the trans temp light coming on, I removed the check valve and installed a 3/8" flared fitting and 3/8" barbed fitting joined together to negate the need for the check valve. I'm still experiencing the trans temp light after a short drive after getting rid of the check valve and both transmission lines are still cool to the touch at the radiator. The transmission is shifting great after the rebuild until the OD and trans temp lights come on and stop overdrive from being active. I've disconnected the battery to clear any history the PCM may have stored and I'm about to take another test drive to see if the issue is fixed. Does this sound like a defective governor/trans temp sensor issue or are there other things I should check for?

 

Probably your rebuilder installed the wrong governor pressure stuff into the trans. Those are classic symptoms of a mismatch. Might wanna call your rebuilder, see what year truck he ordered parts for, and see if that matches your truck. Sensors changed in 2000.

 

That could possibly be the case. He beefed up the transmission for towing and did use several 47RE/48RE parts, such as the 5 pinion planetary, extra clutches in the overdrive unit and front drum, Sonnex sure cure, Transgo shift kit, etc.

 

Just to follow-up, the transmission rebuilder did use some late model electronic parts in the newly built early model 46RE transmission. Once the electronic parts were changed out to the early model ('96 - '99) electronics, the trans temp and overdrive lockout issues are gone.

Thanks again for the tip.

 

Awesome. I love the easy ones.