Trying to figure out what might be going on with my rear axle. The left rear wheel had a wobble in it. Moved the wheels around, replaced the tires, rebuilt the differential and replaced the left axle shaft, same left rear wheel still has a wobble in it. I get a vibration starting at around 60mph on up to about 75mph...

I have 4 recent alignments. I don't understand all the measurements for the rear axle.. But I am looking to see if the axle tube could be bent.. Though i don't think that would cause a wobble in the axle shaft unless it was severely bent

This is 4 different alignments done on two different machines by two different shops.
Keep in mind that there is a slight wobble on the left rear that was there during each alignment.


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Annaleigh what sort of alignment shops are you using? Are they those inside tire shops?

 

Ignore the camber, this is a solid rear axle and the tilt shown reflects that there's a difference in the height of the two rear tires, one is slightly taller than the other. The differences in the toe shows that the axle is "cocked" to one side, this can be from worn spring bushings or the axle itself is further forward on one side verses the other clamped in U bolts. I would say it's from the bushings as one reading is opposite the other in the two checks.

 

Your wobble can either be from a bent axle or a bent wheel or an out of round tire.

 

Could it be a bad casting of a brake drum? Have you tried swapping them to see if the vibration follows?

 

Yes JWA one shop was the tire shop where I bought the tires.
The set of specs without drawings were from a shop that is in a separate building from the tire shop but owned by the same person. That shop was supposed to know how to and have equipment to bend the I-beams if necessary. Neither has gotten the alignment right. I got a line on a good shop from a Mac Tool guy to a place that is supposed to work on big trucks and has the equipment to bend the beams if necessary.

Baddad, I was concerned with the toe and camber that it might indicate a bent axle housing... But one has to keep in mind that there is a wobble in the left wheel..
JWA had cautioned jacking the van up from the center of the differential housing. I remember reading something about that also. IF it had bent then it would be in a positive camber it seems..

Jeffreyclay, Monday we are going to put the van on the lift and swapping the drums around will be one of the things we check. The manual says to check the axle shaft run out on the center hub on the axle but I do not have the adapter to do that so I will have to remove the wheel studs in order to clear then to check the run out there.

BTW I got the posting problem solved. Had to unblock the adds..

 

Baddad's observations are very much my own initial thoughts, especially seeing the thrust angle readings. Great observation BTW!

My suggestion as always when it comes to springs, mounts and suspension in general for our E-Series vans is visit a big truck shop who specializes in spring and frame work. Most are far, far more competent and experienced in these areas, they're not in business to sell tires and such.

I use a tire shop's alignment services but only to take readings. One in particular allows me to be in the shop with the technician which is just about the only way I'll let 'em work on my vans beyond mounting, balancing and rotating tires I've bought from them.

Do let us know what sorts this out Annaleigh!

 

OF course this pertains to the front only JWA

The last alignment (one with the cute little pics) was a recheck and I wound up helping the guy and that is now the closest the front end alignment has been. That day the shop was working overtime and they didn’t say anything about me being in the back with the guy doing the alignment. Normally they don’t allow it.
The tech started with the steering wheel locked in the straight ahead position and wondered why the toe was so far off. I told him for get about the steering wheel, sit in the van and turn the steering wheel till the right front tire shows to be in the center of the alignment spec then lock the steering wheel in place. Once he did that he was having trouble getting the left wheel aligned. Every time he turned the sleeve the right wheel would move a little throwing the rite side off. Finally after coming to the conclusion that he had no idea what he was doing, I just grabbed the right wheel and held it in the centered position on the alignment machine and told him to turn the adjustment sleeve till the left side was centered.

There is only one adjustment sleeve and one adjustment he needed to worry about, the toe.

There is one link that runs from the pitman arm over to the right wheel and has no adjustable tie rod ends. The left side is the adjustable side and connects to the (drag link?) for the right side, pretty simple.
Next time I will just use my level to adjust the camber straight up and down by shimming under the spring seats and set up strings to adjust the toe! I am so done with these shops and after market parts stores around here...

Right now it seems to be doing pretty well for the past 500 miles. Before every time they lined it up I would start seeing a new wear pater on the new tires!!!

 

I checked the run-out on the face of the drum installed on the axle as well as the axle shaft without the drum.
I thing everything is ok according to the readings I took. I needed a roller tip for the dial indicator but didn't have one. Using the standard dial indicator tip makes it difficult to get a accurate reading on rusted surfaces even after you clean them up.



Here is the brake drum face run-out. The drawn in dial indicator indicates where the measurements were taken from in all the pics




Here is the axle shaft face run-out. The measurements in Red were taken right at the stud location and the blue was in between the studs. Stud #5 shows .005 but when i rotated the axle flange 1/4 to 1/2" away from dead center of the stud, the measurements matched the blue measurements between the studs. The wheels are factory steel wheels and then mount against the axle flange right around the studs, about 1/2" out around it.
It is also interesting to look at these measurement and compare them to when the brake drum is mounted to the axle flange.




Because I did not have the adapter for properly checking the center hub on the axle flange and clear the studs as one rotates the axle, I had to place the dial indicator at a angle and just clear the studs.



There was no measurement specs for outer edge of the axle flange in the manual because it says to check the inner hub as in the pic above. Each measure was taken right at the studs.




The run-out on the rims them selves. We fastened a pry-bar down on a block of wood and placed the tip of the pry-bar about a 1/16" away form the outer edge of the rim with the tires mounted to the rim and still on the van. We rotated the wheels by hand and could see no visible wobble or up and down in the steel rim.

Interesting ws when starting the engine and putting the van in gear allowing the wheels to rotate at idle, you could see a wobble and up and down.. his lift is one of those with a single post on each side of the car. The legs of the lift are much like the ones on the old single piston type lifts that spread out. When we were letting the wheels spin at idle, the van had a slight up and down bounce on the lift. The tires have been balanced and re balanced. I could also feel the bouncing sitting in the drivers seat.

 

Oh, I forgot one! This is the stud run-out which the manual shows it can be up to 014