My tranny has slipped twice in the last month. It starts off in first just fine and then the motor reves up when going into second. Both times were after idling for a long period, and the engine temp had gone slightly high at 210F. It normally runs around 200F on these really hot days with the A/C running. The radiator is new, but I may need to go with a lower T-stat.

Is this slipping a precurser to the tranny going out or is this a normal action for the tranny fluid getting so hot?

The truck has 135,XXX miles and the tranny was rebuilt at 60,XXX.

 

I had that same problem with my '00. I changed to tranny fluid and added some Lucas Tranny fix and it never happened again.

 

Check the fluid. It may need to be replaced (the fluid, that is).

 

How do I know if the fluid needs changing? I have only had it since Dec. 05 and less than 6000 miles.

I have a few receips for past maint. and repairs by previous owner. The only tranny issue included was the rebuild.

 

When it's no longer red in color.