Engine/Transmission (1998.5 - 2002) transmission Problem-Help!

[EGidley]

Okay so my 1999 auto with 108K runs and shifts perfect except while climbing decent grades (4-6%) and towing my 4K lb. trailer. Instead of downshifting out of overdrive to a lower gear it stays in overdrive and loses power and the rpms surge up and down about 500rpms. I've been manually shifting out of oversdrive to solve the problem for now. I can also stomp on the pedal and it will downshift too. Anyone have this problem and know the cause? Thanks...

 

[bmoeller]

Sounds like the torque convertor clutch isn't staying locked.

 

[OPoole]

Does it surge alot like the TC is locking then unlocking. . Locking then unlocking over and over? If so you need a noise filter.

 

[monkeyman]

There are many solenoids in the valve body, including an overdrive one. Could be sticking, or faulty. Cheap fix might be as easy as changing trans fluid and filter if you have not done it in a while. I change mine every 30,000 miles. Any trans shop with a reader can tell what is wrong.
Rick