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1977 Bus - Front Caster Misaligned

Posted: Sat Dec 12, 2009 7:47 pm
by Sluggo
After going to the first alignment place where the guy told me that my extra negative camber on the left rear tire was causing my pulling to the right and Colin telling me that that sounded dopey I went to another shop with much more high tech equipment. They said the left rear does have too much camber but that my pulling to the right is being caused by my front right caster being 2* off. It sits just a little behind the left front. Since there is no sign of a major impact he thinks that maybe someone hit a curb or something just right. Says I need to go to a body shop and have it pulled forward. Then I can bring it back to him and he'll cut me a break on the price of having the alignment done again. He adjusted the front let camber to help compensate for the pulling to the right. He said will will wear out the tires unevenly but if I get it fixed soon it shouldn't be a problem.


I like this guy. He has a '61 Ragtop, '74 Convertible and a '61 Bus!

One Stop Auto in Eagle Rock, Ca. Suggested by Bob Costa's Wife Linda.

Anyone else experience anything like this?

Re: 1977 Bus - Front Caster Misaligned

Posted: Sat Dec 12, 2009 8:43 pm
by Amskeptic
Sluggo wrote:After going to the first alignment place where the guy told me that my extra negative camber on the left rear tire was causing my pulling to the right and Colin telling me that that sounded dopey I went to another shop with much more high tech equipment. They said the left rear does have too much camber but that my pulling to the right is being caused by my front right caster being 2* off. It sits just a little behind the left front. Since there is no sign of a major impact he thinks that maybe someone hit a curb or something just right. Says I need to go to a body shop and have it pulled forward. Then I can bring it back to him and he'll cut me a break on the price of having the alignment done again. He adjusted the front let camber to help compensate for the pulling to the right. He said will will wear out the tires unevenly but if I get it fixed soon it shouldn't be a problem.
Caster is not adjustable on a VW. You did not say if it is positive or negative caster, but I am going to assume that it is negative.

Advanced Alignment Options
(please share the below with your alignment specialist)

The camber on the VW is adjusted with an eccentric upper ball joint cam.
As you rotate the cam inside the torsion arm, the ball joint and steering knuckle describe an elliptical circle. Because it is a circle, you can get your correct camber in *two* places, the "backside" of the circle or the "front side" of the circle. The way the eccentrics are installed, there is a little notch that is supposed to face forward. This is what sets the intrinsic caster as you adjust the camber at the correct part of the circle.

If you have suspension damage, you may be looking at new torsion arms with new ball joints from Bus Boys real soon. Then you will have correct caster again. Do NOT be yanking this front suspension into alignment. If you want to help, you *can* loosen the four bolts through the frame and try to work every last bit of play in the bolt holes towards rotating the beam backwards, then re-tighten while under this backwards load.

Warn Walter that we are all looking carefully at updated ball joints and some sort of assurance that the arms he refurbishes are accurate and not bent. I think I got some bent arms from him and the stiff new ball joints, we know what a fiasco that was.
Colin

Posted: Sat Dec 12, 2009 9:16 pm
by Sluggo
Two questions:

1. So if I replace the torsion arms & ball joints that will eliminate the need for a body shop?

2. Is it safe to take on a road trip? The guy at the shop said it was. Just to watch the wear on my tires and have it fixed soon.

Posted: Sun Dec 13, 2009 11:04 am
by Sluggo
Forgot to ad that the mechanic says my rear does not sag. He said it looks just right except for the negative camber on the left side.

Awaiting your vulgar comments.

Posted: Thu Jan 07, 2010 11:12 pm
by sgkent
The caster angle is the angle the tires move up and down when you hit bumps. It should be about the same on both sides (3 degrees). There is an allowance of 40' which is 40/60 or 2/3 of a degree. If it is more than that then Colin's suggestion about the bolts is the only one I know of. If the arms are bent then the angle up and down can change but it seems to me there is no guarantee that will solve it. My 1977 recently came back at 3 degrees 30'. (3.5 degrees).

There is also thrust angle - which is kind of how far a wheel is ahead or behind of its partner. Both wheels can be pointed straight forward but one can be ahead or behind a little - in a bad case like an old ford pickup crabbing down the highway crooked but going straight forward while it looks kinda sideways.

Normally in my experience pulling is either brakes or camber. Caster affects how stable the car is and how well it handles bumps. Here is a good site to read about alignment. And, alignment is kind of an artform. The new places all have high end optical gauges which give tremendous data. But most new techs, at least here in Sacramento, haven't a clue on old cars like a bus. The old guys who know how to align a bus usually don't have the new high end equiptment. They have the old bubble gauges which can get you close but not dead on. But they know how to do buses. We have the same issue in finding the right shop who can put it dead on.

http://www.familycar.com/alignment.htm