Rear Axle shifted?

[70spider]

Hello, I hope the driving season is treating everyone well. I noticed some time ago that my rear axle looked like it was shifted. I really didn't pay much attention to it as the car drove (tracted) well down the rode. I figured after doing the rear suspension (springs and shocks) the offset would be better, but it isn't. Is this normal?
I drew a diagram as I could not get the pictures to show what I wanted to.

Note: I haven't done the bushings on the trailing arms and panard bar yet, thats next.

[coise]

I´m happy to see that I´m not the only one with this problem. My car moves like a crab... All my bushings and bars are in good shape and not bent anywhere. Any solutions or advice would be welcome.

[RRoller123]

the actual track width is shorter in the rear?

[70spider]

the actual track width is shorter in the rear?

Yes, not by much. I measured the width from the center of the tires and the front is 133cm and the rear 131.5cm. The total difference of the rear wheels is a 2cm shift to the pasenger side, I measured this using a meter stick from the apex of the wheel arch on the body panel., If I could get the axle to shift 1cm towards the driver side, in theory, it should be centered.

[aj81spider]

You're assuming your body panels are perfectly aligned. I don't think you can use body panels to measure alignment as lots of things can cause them to move around.

I might park the car and draw two lines with chalk from the front to back wheels with a straight edge. Mark the center of each wheel as well. Then move the car and connect the centers on each side so you have a big rectangle. Measure from line to line in the front and in the rear - that will be a more accurate measure of the track width in front and back. Also look at whether the short sides of the rectangle are perpendicular - that will tell you if the axle is canted at all.

If your axles really are as drawn then the left side angles in front and back should be 90 degrees on the passenger side and 90 degrees in the front driver. The left side line will be angled in slightly so the angle at that wheel will not be 90 degrees.

Once you have all those measurements you'll have a better idea of whether you have a problem and what it might be.

[RRoller123]

Stretch a string, tied to jack stands, around the front and back and then adjust the stands so the string just barely touches the outside of the tires (or better yet rims if possible. I did my toe-in alignment this way. Reading width from the center of tire will give you a wrong width reading because of the toe in. This will give you a pretty accurate picture of what is going on and if you center the steering wheel, you will see visually any gross errors in toe-in setting. I set about a 1/8" gap at the front of the front rims to set the toe-in. probably too much, but it seems to run and track well.

The car must be level, hence I put it up on boards. Doesn't look level, but it is.

[toyfiats]

The front track is wider than the rear, but in any case absent frame and/or body damage a shift to one side is most likely bushings. I had the same issue years ago in my first 124 Coupe, but in those pre-internet days had no idea what the problem was.

http://forum.mirafiori.com/mirafiorum/n ... &msg=21209

[70spider]

a shift to one side is most likely bushings.

My bushings are shot, they are all cracked and "smashed" looking, good technical term, so I planned on replacing them. According to the manual I am to do them one at a time. I plan on sanding and painting them so it will take awhile to get all five. Once I get them back in I'll give an update if that solves the shifted axle. Thanks for all the good replies.

[vandor]

This is common. I think the only way to adjust it is to fabricate an adjustable panhard rod.

[coise]

I think you are right Csaba, but I would need some kind of model.
Thanks for the advice

[DieselSpider]

If you change the ride height then you will also change the position of the rear axle when the car is unladen/at rest as the tracking bar will be at a different position in its arc. It all shifts left and right as the rear suspension moves up and down.

[coise]

That make total sense! Thanks. That´s probably why my car rides like a crab....
I have progressive lowering spring, so the only way to correct it is with an adjustable Panhard rod.
Anybody has done that before?

[vandor]

If you change the ride height then you will also change the position of the rear axle when the car is unladen/at rest as the tracking bar will be at a different position in its arc.

The axle is often not centered even on stock ride height cars.

[DieselSpider]

If you change the ride height then you will also change the position of the rear axle when the car is unladen/at rest as the tracking bar will be at a different position in its arc.

The axle is often not centered even on stock ride height cars.

Yep and lowering or raising can make it better or much worse. A good alignment shop will check this during their thrust line verification.

[70spider]

Well earlier I was talking how my Spider's rear axle has a 2cm shift to the passenger side, I found out why. From the photo of my panhard rod, Csaba confirmed it was bent and that my Spider whould have a straight bar. Apparently it had been bent by th PO causeing the 2cm shift. I recieved the new from AR today, here is the comparison:


And apparently this was the cause of all my noise in the rear when I made a right turn.