HARD SHIFT 2006 Chevy 2500HD diesel. My transmission started heating up while pulling my trailer up a grade. It caused the engine temp to rise and the thermal fan to run mostly nonstop,which kept engine temp down while trans temp continued to rise. I had to pull over and stop when trans temp reached 250 degrees and allow the trans to cool. I thought the problem was only while pulling, but while driving up to Big Bear, going less than 40 mph,in 71 degree temp, trans temp went up to 230 degrees. The truck has 83,000 mileson it and I've done maint. on trans including second fluid change just prior to this trip.

Mike Butler

• 6674 Answers
• Posted on May 31, 2009

SOURCE: 1999 Grand Voyager transmission not shifting into high gear

Do yourself a favor & get it scanned at transmission shop, or dealer & fixed as needed,(within reason) . Delaying it could cost lots of money. A rebuilt is about $1500-$2000.

SOURCE: Transmission temp running 160 degrees in my 2007 Yukon Denali

I you did it by yourself is better to tell the dealer that you truck has that problem dont tell them that you did that because you may have voided the warranty.

SOURCE: 1997 ODYSSEY AUTO TRANS SHIFTS HARD BETWEEN 1st & 2nd, 2nd & 3rd

It has nothing to do with the transmission, it's your engine mount thats bad.

SOURCE: 99 chevy lumina 94k mi transmission stopped working. Fluid good.

check fluid level, make sure proper fluid is in transmission otherwise take to trans shop to diagnse if level and type is correct(check at idle normal operating temp)

SOURCE: 2001 chevy monte carlo is overheating when driving

Hi;
If your engine cools down when moving fast, you either have a problem with your water pump or your electric fans that cool off your radiator and a/c condenser. This is controlled by a temperature switch, but these fans should kick on instantly when A/C is selected.