when going 50 or 55 and step on it, not just out of overdrive, but drop a gear for passing the 4L60E in the truck jumps to about 3500rpm's, bumps, then drops to 3000rpm's and bumps again, then takes off...pretty quick interchange though between bumps....? any ideas....Thanks

 

The 4th to 2nd drop would cause this I think, try it in 3rd and see how it does.

BTW I'm hearing that the 4-2 downshift is murder on the 4L60's, so if you know your going to pass, drop it in 3rd.

 

Thanks! Any other ides? Does this mean The trans is going out or some part of it? getting weak? Its only got 17,000 miles on it!

 

I don't think so, if you want have the dealer check it out if its under warranty.

 

mine did that before many times. some times it woudl even break the tires loose at that speed. now its time for a rebuild again

first time around lasting 22k
second time around lasting 28k now
hopefully having a performance rebuild this time will help it live longer now behind my new motor