Have a 1989 Cherokee 2 door sport 4.0 that I've been slowly getting into running condition. Engine runs fine now. 5 speed transmission. Clutch seems to be okay.

After I finally got the engine running, 2WD would not engage. 4WD hi and 4WD lo would engage, though I never confirmed if both front and rear wheels were spinning.

Have been driving it around the yard for a year now, in 4WD hi, occasionally towing a utility trailer filled with trash, no problems.

Finally insured and tagged it today and went for a drive to further test it and start on the 2WD issue. About 1/4 mile from the house, at around 35 or 40 MPH, something popped and 4WD hi stopped working. Pulled over and none of the drives would engage. 2WD, 4WD hi or 4WD lo.

Crawling under the Jeep, the rear drive shaft spins freely and the front driveshaft spins freely. Both slightly spin with the Jeep stationary and in neutral with the engine running. I can stop them spinning with my hand. In 2WD, only the rear driveshaft was rotating while in neutral. In 4WD, both the front and rear driveshafts were slightly rotating while in neutral.

Any insight on where to start? I plan to pull the differential covers off and see what they look like inside unless somebody thinks it's something else. thanks.

 

Sounds like a broken transfer case chain. It's the most common failure for your symptoms. When it pops, you lose drive to both shafts.
Forget the differentials for now. They wouldn't cause a total loss of drive. Your problem is almost certainly in the transfer case.
Start by draining the transfer case fluid. Look for a pile of metal chunks in the oil. That will confirm the chain or internal gears are gone.

 

Have you verified that the selector shaft going into the xfer case is actually rotating to where you think it is based on the shifter handle position. The connection mechanism between the shifter handle and the case crank arm is poor and it sometimes slips out of position. Also I think you never had the back wheels connected in 2wd, but when you put it in 4 hi it engaged the front shaft and thats how you drove around. Lastly when you said you could rotate the shafts by hand.....were your wheels on ground?

 

I'd be verifying your tcase is shifting into each position before I start getting overly involved with dismantling the drivetrain.

Forget the physical floor shifter, crawl under the jeep and ensure the shift arm on the tcase itself is fully engaging the selections properly. For all you know it could be getting hung up in 4hi or even in neutral.

The chain breaking doesn't default the tcase to neutral either, that will eliminate the front axle from spinning sure but it doesn't mean the rear axle isnt able to recieve power either - that comes down to the mode fork and its position in the tcase.

 

Have verified the selector shaft is moving in concert with the shift lever.

Further verified that with the cherokee sitting on the ground, when in 2WD, and in 1st, 2nd, 3rd, 4th & 5th gear, the rear driveshaft is spinning, but the rear wheels are not.

Verified when in 4WD hi, both drive shafts are spinning, but neither the front or rear wheels are spinning.

Seems to me that both the front and rear differentials have issues...

 

This sounds ridiculous, but if you have all 4 wheels on ground, and tcase in N....can you turn the driveshafts?

 

As in all 4 tires are on the ground - both driveshafts are spinning while in 4wd... but the jeep don't move....

Whats your driving style really like to consider potentially blowing up both differentials in one incident on a public road. Your a savage arent you!?

 

Yes

 

Yep, all 4 tires on the ground, both driveshafts are spinning and the Jeep won't move.

Not going to deny being a savage, but picked it up for a couple hundred dollars a couple years ago from a junk yard (who still had the title, yippee!) as a project with my teenager. He ultimately got himself a Mustang..., so the Jeep sat for quite a while. Finally got around to fixing the engine and discovered 2WD wasn't working, so I'm assuming the front differential was already blown. I guess I blew the rear one, but honestly, it didn't take much.

 

Actually, it was the back that was blown , thats why it didn't work in 2hi...and now you have blown the front also. Most of this is probably not worth fixing. Im sure both pinions and ring gears are trashed, or you have sheared off some other large piece of metal in there...the pictures might be interesting though

 

Duh, you're right. Rear would have already blown...

Not worth fixing??

 

You won't know for sure till you open up each diff, but your probably going to need both diff's. I can't imagine the damage that would allow you to spin both driveshafts by hand with the wheels on ground. Up here, even a junkyard diff would run several hundred bucks each and your going to need 2......On a 35 year old truck that can't be in the greatest shape. It's your pocket and only you know your situations

 

www.car-part.com. get some axles and be on your way.

 

Looks like I found the problem with the rear differential. Somebody was in there and removed some parts... Not sure yet what's going on with the front one. Will investigate it later. Will probably remove the front drive shaft for now, and get the rear axle fixed or replaced to get 2WD working. This is a Dana 35, right? If I wind up replacing with a 44, what year parts cars should I be looking at for a whole assembly?

 

That explains a lot!

Now you have a VERY open diff!