Bigmd

Hey guys new here. Finally decided on a winter vehicle after dodging huge potholes and getting stranded a few times with my 08 Mustang gt.found a guy near me selling a 97 Grand Cherokee . It has 144000 on it and was asking 1800 but lowered it to 900 after rear started making noise on a recent trip back from MA.looked at it today and it looked good no rot .he had rear drive shaft out but I could hear a slight grinding in the rear.it drove decent for a 17 yo car.the engine bay was grimy and looked like it had valve cover leak.i got him down to 800 and will get car tomorrow.anyway what's best course of action for rear ? Tear inTo it or shop for a complete rear end?what other models rears fit?thx In advance

dave1123

Personally, I think you're buying a heartache. That rear end is a lot of work to either repair or replace. If you're willing to spend the money, go for it.

I would check the undercarriage for rust where the control arms attach to the body and the general health of the transmission.

In most cases, the rear diff and the transmission are the weak points of the ZJ, as well as the all wheel drive t/case. It sounds to me like it's the 242 Selectrac if he's driving it on the front shaft only.

I'm going to tell you, DON'T BUY THE FIRST JEEP YOU LOOK AT! I know from experience you can get hooked quickly and fall in love with it. I went looking specifically for a 4.0 I6 with the 242 Selectrac t/case because I knew they lasted the longest, but because the 242 is used in 2WD most of the time, the rear diff takes most of the wear. That and the transmission were what failed on my 97. Then the rear control arms tore out of the frame and after investing around $5000 on parts and labor, I had to part it out.

Everybody wants the V8s, but ones in good condition are getting scarce. If what you want is longevity in a DD, get the 4.0. Just my opinion.

I've been around cars and trucks all my life, but still was smitten by the looks of my ZJ. I have to say it was the worst mistake of my life, not looking it over carefully before buying it.

Welcome to CF!

Bigmd

Dave thanks for response. I figured worst case would be a rebuild of rear.which me and a buddy could do. Or I could just do a good used rear, I just need a car for the snow and I can garage the stang.the main thing that attracted me was price and he was a few miles from house.

Bustedback

Swapping in a boneyard axle is the cheapest and easiest option. An axle for a ZJ goes for about 150 bucks in my area. Once you get a Jeep you're never going to take the Mustang out of the garage. Oh, and you'll have a stupid grin on your face while driving a Jeep. It's not just a car, it's a sickness.

Bigmd

Haha thanks. I always said I would have a jeep if I didn't have mustang. Now it's more a necessity . Hate worrying if my summer performance tires will get me home when it snows.i think I'll make the move and get it. Especially for 8oo. I've looked on CL and see plenty of rears. Besides my year what others jeep rears. Can I use? How. Bout ford 8.8

Bustedback

You can do the 8.8, but it is not a bolt in option. The ZJ has coil springs at the rear, so you would need a ZJ rear axle in order for it to just bolt in. There are a few places that make the brackets and spring cups so you can fab in a Dana 44 or an 8.8. But it's just not worth it for what you have planned. The 97 has a D44a if there is a V8 under the hood. A Dana 35 is the axle behind the 4.0.

Bigmd

Ok was jus wondering because my buddy has a few laying around. I'll look for a Dana 44

Bigmd

Also it's a 96 I made mistake in post.

dave1123

I think the Ford 8.8 requires some modifications for mounting the springs and control arms, but other members would know about that. Just be sure to match the axle ratio with the front.

The hardest part about rebuilding the rear diff is getting the pinion bearing preload right and setting the backlash and tooth contact on the ring gear. There is a very good write-up on the forum about this, but it's been around long enough that the pics are no longer available. It's also about the D44a, but the procedures are the same.

If you go with a used axle, pull the cover and check it out BEFORE you pull out your old one.

Bigmd

I located a 44 not far from me with rotors and calipers from a 2001 for 100. Bucks. Not sure of ratio but also
Not sure what ratio is in truck I want. Bye the way does the ZJ have disc brakes on rear

Bigmd

Ughh I need a 35 misread the post

Bustedback

95-98 ZJs have rear disc brakes.

dave1123

You'll also need an axle from a 98 or older because yours mounts with 4 control arms and 99 and newer only use 3. You can use a D44a but you'll need a modified drive shaft or change the yoke on the diff, and that requires resetting the pinion bearing preload.

The ZJ does have rear disc brakes after a certain year, but IDK what year. My 97 did.

It seems Busted is beating me to the punch every time! Good for you!

BTW, in most cases, the ZJs with the tow package used a 3.73 ratio and the ones without used a 3.55. The tow package Jeeps had a trailer hitch, lighting package, and aux trans cooler.

Bigmd

Well I appreciate the info from both of you guys . Sorry for all the questions. A guy got back to me with a Dana 44 for 100 dollars. Not sure if it worth it if I have to get other stuff

dave1123

The D44 from a 2001 only has 1 upper control arm mount. Your 97 uses 2.