This morning I was driving my truck to work and about 15 minutes into the drive my overdrive shut off and the Trans temp light came on. I checked the fluid and it was still at the right level. My ujoints on the drive shaft are going bad, could the vibrations from that be putting stress on the transmission?
I have a 99 1500 4X4 with a 5.9

 

What makes you think its overheating?
Did fluid smell burnt?

Dave

 

More likely the check valve in the cooler line is clogging up.

 

Thanks for the reply. I didn't smell anything and was just going off the light and o/d shutting off. I'll check to see if it was that valve.

 

Since it got hot enough to turn on the Trans Temp light, it's time to change out the ATF. It's cooked. Might as well do the check valve delete at the same time.