WJ Issues

HarryS did pass the time by typing:

Someone rotated the tires by jacking under the pumpkin?

From all the posts about failed rear ends in vehicles made in the last 5 or 6 years or so by DC they obviously have done something wrong with the design.

Not changing the oil in 48K is 'not' a reason for a failed rear end.

You don't hear of CJ or YJ or Cherokee rear end failures, but grands, well... And a bunch of TJ's too????

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

HarryS wrote:

Mike Romain did pass the time by typing:

#1 cause of failure in the ZJ is having some nimrod jack the rear up under the diff. I see it all the time at a local tire shop.

Pardon the dumb question, but how does that lead to a failure?

It's not a dumb question, it's a dumb design. :)

DC used thin wall tubes and only pressed them into the pumpkin with half assed plug welds to keep the tube from rotating. Jacking from the diff can bend the axle assembly taking the bearings and seals out of alignment just enough to cause excessive wear. Older thick wall steel (welded) axles didn't have that weakness.

Which diffs are susceptible to this?

Claude

For the most part they all are. Car makers have cut weight where they can and that has created weaknesses in what used to be your basic hunk of iron. Now diffs are aluminum and the tubes are thinner.

It's just not a good idea to ever jack from the pumpkin. They make trusses to strengthen axles for larger tires and off road bumps. Some bolt, some weld.

homemade one

commercial unit in product reviews.

Well it does make sense I had talked to my friend and he said he jacked his WJ by the pumpkin all the time. I told him about the replays on the newsgroup. He was kinda pissed that he may have caused the damage. I guess that is why jacking points are specified in the O&M. I was wondering if damage can be done by jacking the tube near the wheel? The TJ shows the jacking points to be on the tubes.

HarryS

HarryS did pass the time by typing:

If I have to jack on the tubes it's usually directly under the shock mounts, or as close as I can get, so as to put the most force directly up and on the suspension.

Got to agree it was hard for me not to jack from the diff. Did it all the time in my old chevy. It was a dealership mechanic that warned me of jacking under the diff when I was in there for some warranty work.

My solution was to get a 3ton floor lift. Just using the frame points it can bring the wheels a good 6" off the ground.

The only time I have jacked under the diff was to raise/lower the axle for some suspension work. And then it was just the axles weight. The ZJ was up on jack stands.

Good points I will pass it on.

HarryS