Out-of-round Tire, Bent Wheel, Or Bent Axle?

I'm gonna go with bad hub. The used hub in your second video doesn't actually look to wobble much (if at all), I think it is the one lug stud going around that makes it a bit deceptive, the hub itself looks to be running fairly true. If it was me, I'd get a replacement hub, install it and re-check for run-out. If still a wobble, likely old hub badly bent, axle slightly bent.

Another thing to watch or check is swedged lug studs. It used to be standard practice to have the drum locked to the hub by pressing the lug studs through the hub, installing the brake drum then a tool ran down the lug stud and flared the lug stud splines out kinda like a rivet to lock the drum to the hub. If you look at the lug studs from a side profile view, you can see where the splined part of the lug stud (where it comes through the hub) are flared out slightly. If this is the case, good chance a new or different drum would not seat properly over the lug studs. Doubtful this is the case though as your original hub definitely has a wobble without the drum.

 

I have bent a hub with a 3 jaw puller.

 

Here are the results from a couple of the suggestions above.

First, here is a video of a pointer in the center of the spinning axle. I don't think the axle is bent, but maybe it is.

I did the marker test next. I used a black marker first, then rotated the hub 180 degrees on the axle, then used a silver marker just inside the black. The black and silver marks lined up exactly on the same side of the hub (the black is more faint, but it's outside the silver):


According to ITLKSEZ's theory, that means the hub is bent, not the axle. Just to confirm the theory, I repeated the same experiment with an old cracked hub. This time the results weren't so black and white. The lines only overlapped 3/5ths of their travel. How would you interpret that? The cracked hub is on the left and the hub off the jeep is on the right:


I'm going to order a new hub.

 

How about a good used axle and hub rather than a new one of maybe questionable quality? Depends on the manufacturer I suppose.

 

Here's the rest of the story. While I was waiting two weeks for a new hub to arrive, I looked at other things. The driveshaft was wobbling at the pinon end. What was interesting was the differential was pointing up, causing a slight negative angle compared to the other end of driveshaft.


On top of the springs underneath the axle tube are two shims. Those shims are causing the differential to point up (Ryan figured this out). What is the purpose of those shims? They were causing another problem besides the angle. There's a head of a bolt that goes through the springs that seats in the spring mounts to keep the axle in position. The shims were covering that bolt head so the axle tube could slip on the springs. I removed both shims from both springs on the rear axle. That seemed to fix the driveshaft u-joint angle problem.


This is starting to turn into an escalation of issues that usually happen when house plumbing is involved. It usually goes like this. A faucet has a drip. In order to take the faucet apart to replace an o-ring, you have to turn the water off under the sink. However, the valve's handle under the sink won't turn. The valve needs to be replaced. In order to replace the valve, you have to turn all the water off to the house. Sometimes, it's impossible to get the whole-house valve to completely shut off. Then you try and remove the valve from the wall, but that causes the pipe the valve is connected to to unscrew instead of the valve. At every step, things get more complicated and serious. That's how this wobbly wheel project is going. This picture shows the slip-joint on the driveshaft was completely compressed. There was no room for the driveshaft to compress even further. The driveshaft must be too long. I needed to shorten the driveshaft by 7/8 of an inch.


I removed the driveshaft and measured and cut off the pinon end. Then I ground off the old piece of driveshaft tubing from the pinon end and pressed the end back into the shortened driveshaft. I replaced both u-joints with new ones.


I reinstalled the driveshaft (before welding the joint) and tested how true it was. Unfortunately, the driveshaft was just as wobbly as it was before. Could the pinon be bent?


I removed the driveshaft and welded the pinon joint. Then I reinstalled the driveshaft.


Eventually, the new hub arrived. I didn't realize the hub would come without lug bolts. I had to order those and wait some more. When the lug bolts arrived, I used a press to install them in the hub. I mounted the hub on the axle and installed the wheel.


After all that work, the wheel still wobbles, perhaps not as bad as before. Oh well. The driver's side wheel wobbles, too. I suspect the rear axle assembly was junked at some point and then reused on this jeep.

My wife and I took the jeep on 25 mile test drive. The driveshaft didn't fly apart and the wheel didn't fall off. I call that a win.

 

Driveshaft angles arent right. The angles at transfer case and differential should be equal. If using shims to try to make zero angle at differential, then need a double-cardan at the transfer case. Angles u-joints run at an elliptical pattern so the angular velocity changes trough the rotation. If front and rear joints are at equal angle then they speed up and slow down in time. If not then they argue about who should go fast and when.

Im not a driveshaft expert but I did read a book once. It wasnt a book about driveshafts, though.

 

The magic woid for drivetrains is "Tom Woods." Look them up.

 

cool video, i dig it!

 

That video is way cool! Nice demonstration.

 

The scary part here is that the heads of the spring center bolts weren't engaged into the axle housing.
You can buy center bolts with taller heads on them.
This would allow you to re-use the shims if you desire.
Personally, I would measure the angles for the driveshaft, make necessary adjustments, and go from there.
Maybe for your intended use of the Jeep it will be fine.

 

Yes, and quality pinion angle shims have a flat spot in them for the center bolt to bolt them to the spring pack. In one photo it looks like the doubled up shim is trying to come out......