OK where to begin... I have a 97 4x4 blazer with a 4.3 AT. Now my transmission was rebuilt three times in the span Ive owned this truck. I recently replaced my crank and bearings in it and since I dropped the motor back in I have had this problem that now has gotten progressively worse. It was working fine before this last job I did. I'm gonna try my hardest to explain everything that has happened.

It started where if I drove the car 30-40 continuous miles when the trans was in lockup if I even slightly touched the throttle the rpms would just jump to 3-4000 with no acceleration. It seems that it was kicking out and dropping to OD but slipping. I checked the fluid level saw it was overfilled and thought maybe to much pressure build up. not the case. Now when this would happen the trans would shift 1-2 VERY hard. Then after a rest of a few hrs it would be fine. I drained some fluid to check and to set the level correct..all good. Next day it started banging outta 1st right away from cold to warm. Then I took it on a very long drive across state. I had a large object strapped to the roof which was defiantly adding some strain to my trans. The original prob started almost immediately but cleared right up which never happened. And stayed cleared for the whole trip bout 60 miles. Then return trip was great till the home stretch off the highway pulled off from the light and wouldn't shift outta 1st. I let off a bit at around 3500-4000 and it shifted. But it seems it slipped out every gear back down to first unless I gave it very light throttle until it got to OD. Also on the Highway if I'm in lockup and press 1/2 throttle it kicks down normal to 3rd to pass as it should but if i give it wot it will go to 2nd even if I'm doing 80 which it shouldn't.


Now I thought fluid level in the beginning.not it.. then maybe fluid type but I used ATF D/M which I'm pretty sure is what it takes. Now I'm leaning toward Torque converter but just doesn't make sense how/why it went bad. Ive found threads on here with partial probs similar so I'm gonna try there fixes tomorrow which is TPS test and clean MAF but I don't think its either. Now I'm sure I forgot something so please just ask.

Thanks!

Oh one thing I forgot. I don't think it has anything to do with it but the vacuum lines that connect on the drivers side by the fender. Theres something like 5 lines one has a T and the other has some kind of one way fitting and another leads into the canister on the hood. I have no clue if these are back on right. I did my best judgment with sizes and common sense but I cant find a diagram that really helps me with this. I know one goes down to the tranny but idk where/what.