On our 04 Avalanche the trans is very late shifting, at about 4,000 rpm, unless you let off the gas and then reapply gas. Could it be possible that this is caused by a corroded ground strap from the body to the transmission?
Thanks, look forward to hearing your thoughts on this.

 

is it lacking power when this happens,i have experienced this before and it was a friends tahoe which had a plugged caytaletic convertor.his truck would rev high and as you said let off the gas and reapply and it would shift.when the cats start to plug it can cause long and delayed shifting and lack of power.

 

Thanks chevy55, will check to see what shape the cat is in. Appreciate your suggestion.

 

trans fluid full? smell or look burnt or dark?

 

Thanks Cleveland, trans is full and fluid is real red and does not smell burnt.
what does 63b mean? ? ?

 

it used to be a mos/job when I was in the army

 

Thanks, thought maybe it was a '63 car you had.