I just dropped a new engine in my 97 and for some reason when I'm driving down the highway when I get to about 31rpms right at about 65-70 it just stops and won't let me go any higher. Now did my transmission lose 5th gear? or is there something else?
4x4 if that means anything

 

4th gear*

 

Sounds more more like an engine issue.

 

As I put more thought into it since I only have 100miles on my new engine, and since it's a 4 speed with overdrive maybe the computers need to be played with

 

It is NOT a 4 speed with OD there are only 4 speeds period in the AW4 trans not 5 period. You have other issues.

 

I've looked it up the auto trans is a 4 speed with overdrive

 

I'm waiting for one of the Jeep Gurus to chime in here and say "Oh, yeah - there was an option for that" but I suspect you may have been misled.

On the other hand, my Jeep (97 4.0 Auto) does 70mph at 2200 revs with 235/75 tyres so I suspect there's something not quite right with yours. Perhaps the torque convertor isn't locking up? Or maybe it IS locking up and you're actually in third. I'm sure someone with a knowlege of the gear ratios would be able to work out what is actually happening.

Also, you DO have a 4.0 don't you? Not a 2.5?

 

Sometimes a cold trans fluid check will show a bad torque converter...not always, but give this a try.


If the fluid level on the dipstick doesn't drop to, or below, the add mark instantly, you either have a bad TC or trans oil pump.


This has been proven by other Heep owners.

 

Yeah it is a 4.0 I will check
I'm gonna go back to the shop that did the engine and see