Aw4 transmission is driving me crazy, help please!

My Tranny started slipping real bad (leaking from every corner as well), so I put a new Tranny (80k miles from junk yard) in. changed the filter, fresh fluid and cranked it up. Same shit.
Checked the TCU and changed it. Same crap again.
Changed the TPS, adjusted the cable, still the same crap.
It’s fine for while then all of a sudden it stalls and RPM goes to 5 grand and it seems it's in the first gear. It won't go faster than 25 mph.
Engine runs fine and nothing wrong with it, it start right up and pulls strong.

Help me out here; I’m about to take a sledgehammer to it.


It's an 88 XJ with 4.0 and AW4 and NP242 case.

sounds like your tranny went and then you put in a junk tranny. ahh return the one you just got and get another.

It could be possible but what are the odds? it has to be something else, what? i don't know, i might just take it to a transmission shop and have them scan and test the hell out of it.

Might be the torque converter. Did you replace that when you installed the junkyard tranny?

I would check the torque convertor... Thats what it sounds like to me

Another vote for the torque converter, changing transmissions wont fix a bad converter. I was once told to always change the tc with the transmission.