I have a 03 Monte Carlo 3.4. The case is that everytime it shifts it's really hard, sometimes it does it, sometimes it doesn't. I've replaced the mounts both motor and tranny but it still does it. Help please? Soon as possible

 

If you need immediate, accurate help take it to a trans shop and get it diagnosed by an expert. Harsh shifts on these transmissions have quite a few potential causes, so it'll be impossible for us to tell you with any level of confidence given the extremely limited info provided.

If any codes are stored related to this, that could help narrow the cause possibilities down from a lot to a few as there are a few different hard shift related codes.

A few of the causes are relatively easy fixes, but be prepared as the vast majority aren't and can require the trans be removed to correct - especially if it has higher mileage.

 

I had hard shifts somewhat regularly and was lucky just needing to replace the tranny solenoids. Still a good bit of labor though.

 

my'03 SS did that at 100K ended up with a tranny rebuild?

 

Ive had hard shifts several times with these 4t65 variants. Everytime it needed a full rebuild.