erupert66

My son recently bought a '91 Cherokee. It seems to me like the trans is going up. The PO had just replaced it with a used one. It started as slow to upshift into top gear (don't recall how many speeds they are) but now it's not upshifting until it's warm. Looks like the trans fluid is topped off and clean.

Not familiar with Jeep too much, on my '95 F150 trans codes can still be accessed from the flashing check engine. Anything stored in the Jeep? Does this sound like a bad torque converter or worn out trans? Would really suck as we drove it with no issues and he's only had it about 2 months. Looks like the PO was a dipsh$% anyway as all of the "spares" he gave us (Power Steering, Brake Master, etc) were all from the wrong year Cherokee. It's also leaking from what I assume is the rear main which he should have had the sense to change when the trans was out.

Thoughts? Anything to chase? I have some Lucas no-slip that I could probably add if we drained out some of the trans fluid (it's a bit over the full mark when hot and running.

jay_sco

Can't help with the trans issue, but I can tell you that the rear main can be changed with the trans in place. 2pc seal, easy peasy.

4WD4EVER

I would recommend holding off on the Lucas and install an OEM trans screen/filter in the tranny first. It's amazing how many shifting issues can be resolved with a simple screen/filter replacement.

The rms is pretty simple. Even simpler if the vehicle is lifted a few inches due to oil pan clearance. I'm @ ~5.5" and mine came right out. Here are the 2 links I used:

http://forums.4wdmechanix.com/topic/...ep-inline-six/

http://jeepin.com/features/rearmain

I had never been in the bottom-end of mine and was a little nervous, mostly about scoring the crank, so I purchased a thin-tipped brass punch to "push" the upper half of the seal out a little before grabbing it with needle-nose pliers. I also turned the harmonic balancer/crank to ease re-installation of upper-half due to the fact that some people have been known to push the wire through the seal trying to force the seal in; I didn't want to be one of them. And I bought a spare rms just in case I was. I'm a total novice, so if I can do it, I'm certain you can too.

The other thing I'd recommend is checking your oil pressure with a mechanical gauge prior to beginning and be certain it has acceptable pressure. If it doesn't, you're going to have the pan off and the oil pump and screen only take a few more minutes to install. Better to know pressure before you go in than to realize later you have to go back in...

Let us know how it turns out.

erupert66

Thanks for the suggestions. I google for some how-to links. I have an aftermarket deep pan on my F150 with actual drain bolt to make fluid change easier. We will see how it's done on the Jeep I guess. Also good news about the rear main, I'll look for some how-to on that as well.

4WD4EVER

Sorry, it took me a few minutes to edit but I included some links. I believe the Four Wheel Drive Mechanix link has the torque specs for hardware in the PDF file that's included.

toasterknight

Cherokees have a drain bolt from the factory so it makes changes much easier. I have yet to find an aftermarket pan for one though.

erupert66

A bit of info that my son just passed along. The shifting issues started after he got it almost stuck in a mud pit that was up to the belly of the Jeep (it's on a 5" ?? lift with 33's). Then, we had some torrential rains here a little less than two weeks ago and it's been worse ever since. I told him that we should look for all of the connections to the trans and spray them with contact cleaner. I figure that we can look for a youtube video on changing the trans and it would show the connections. Of course, laying under it is also an option.

I am assuming that the trans is similar to the Ford in that it's fed info about speed/throttle position to operate the shift points and internal pressures.

It was also running really rich so we changed out the O2 and TPS which seemed to take care of that.

freegdr

Ever adjust the detent cable,

erupert66

Don't know what that is. Only owned it about 2 mos. I've owned some other Cherokee's but a bit newer and less miles so never had any issues. This one has 235K. Engine is original, trans is not. I'll google for an answer but any links you have would be helpful.

freegdr

It regulates shifting along with tps .Worth looking into its other names called kick down cable .Very simple and free....

4WD4EVER

Her's a vid link by esteemed CF member DumaJones:


freegdr beat me to it...

ToddPaul

Hi there, hope some of this helps . . .
I would start by changing the fluid and filter, and if shifting difficulties still occur, then take a close look at your wiring to the trans and make sure it is clean and tight. If after this if you still have issues , look at your shift solenoids sounds to me like possibly a bad drive solenoid. One two shift , is it alright ? Check that solenoid too. PO may have reused these items . Anyway give this a roll, it should solve your issues, and if you haven't, check your kickdown as well. As for the rear main seal, check your valve cover gasket too, be sure its not running down the back of the engine posing as a bad rear main seal.