Hard shift while Passing

I have 96 Blazer 4 door 4x4,I drive my Blazer it shifts through the gears fine until I am doing 90 KM and decide to pass. I push down the gas and accellerate but the rpms Red Line and I have to let off the gas and wait for it to shift itself. I can then continue to pass. One place has told me Tran is going. I was wondering others opions. it shifts fine otherwise.

Thanks

It does sound like the Trans is going, it may just be the passing gear going out, Either way I would have it looked at and get a second or third oppinon

I have 96 Blazer 4 door 4x4,I drive my Blazer it shifts through the gears fine until I am doing 90 KM and decide to pass. I push down the gas and accellerate but the rpms Red Line and I have to let off the gas and wait for it to shift itself. I can then continue to pass. One place has told me Tran is going. I was wondering others opions. it shifts fine otherwise.

Thanks


Tansmission rebuilt but still doing same thing.
RPMS high rev(wont switch) until accelarator released while passing.

From what I know, if you hammer it and it is a really high RPM , it won't change on that transmission due to the damage it will cause if you do.