So, lemme kinda give you guys the specs on what's going on.
I am NOT a car guy, so bear with me and try not to make too much fun haha.

I've had a problem with my transmission before, and had it fully replaced about 2 years ago. It wouldn't go into reverse or shift.

But now, it will shift into reverse and 1st and 2nd gear no problem, but as soon as it tries to shift into the next gear the engine just revs and the RPMs go up to the 4000 mark, and that's just to get going up to 30 mph!

Before this happened, for about a week the RPMs would "flutter" while I was driving in 4th gear around the 2000 mark, as the meter would just go up and down slightly with a slight rev of the engine (if that makes sense).

And about a month ago I had to bypass my heater core since I don't have the funds to get it replaced... So would that have anything to do with it?

Any help with any of this would be fantastic.
Just signed up for this site today to try to find some help.

Thanks so much

 

Sounds like the 3-4 clutch pack is gone.

 

trans is shot. more specifically the 3rd-4th gear clutch bands. same thing happened to my moms jimmy at 108k drove fine until about 30mph then it just revved

 

So... new transmission?
I mean, I literally just had it replaced 2 years ago...

could it be ANYTHING else at all?