I have a 2001 blazer that recently has been shifting hard. It has an automatic transmission but recenlty I notice when it does ****, it bucks a little bit, especially shiffting down. Also it just started to freak ou twhen I acclerate. If I accelerate real slow nothing happens out of the normal... If I acclerate faster though, it freaks out... The RPM needle jumps all over the place and it bucks back and fourth. I am aussming my tranny is done for but i dont here any grinding in any of this. Any ideas on what this is caused by?

 

My 04 Blazer was starting to get a little funky like you are describing around 97K mi. I was considering doing a full flush, but the fluid looked OK. I added a bottle of Lucas Trans oil, and it started to die down, and has went away completely now. I now have 119K on it. Mine may not have been as bad as yours, but hope that helps.

 

Hey! I really feel that if you service the trans and replace the offending solonoid (and perhaps the TPS) you will get another 100K out of that trans! Do some research first! Loads of info in the search feature on this site! Investigate first the simple issues!

 

How many miles are on it? A fluid and filter change with new fluid and some of that lucas stuff might help. It sounds like its slipping really bad. Have you checked the fluid yet? Is it full and bright red? I don't think automatic transmissions will grind when going bad, they'll slip, not shift, shift hard, or not go into gear at all. I just had mine serviced the other day at 133k and GM transmissions usually last a long time (I said usually) in the vehicles I've seen