Scottd

I installed new control arms last year and assumed I had installed them in the same position as when removed. Last night I noticed that my pass rear tire was sitting a good inch outside the fender and my side wall was all scrubbed up from hitting it. BRAND NEW tires I might add. Less than 50 miles on them.
I started playing with the camber bolt but I just couldnt get it to set right. When I managed to get the top of the tire under the fender, then the bottom of the tire stuck out WAY to far. Im missing some kind of adjustment here, I know it.
I measured the frame, took several different readings, everything appears straight (I just measured from several reference points on each side)

Anybody have some insight or tips to get this tire vertical enough to get me to an alignment shop come spring?

larrywalk

What is the rim size and backspacing?

Scottd

They are stock, old school steel rims. Im only having a problem with this one tire. Ill try and look at the backspacing again, but Im assuming because they are stock, this probably isnt the issue.

The only thing that dictates camber is that nut, correct? Am I missing some other rear end adjustment? My trailing arms have equal shims on both sides.

larrywalk

Regardless of rim size, with the car's weight on the wheels and normalized (on a flat and level surface) by rolling forward at least 20 feet, place a 12" long level vertically against the rim edges; pull out on either the top or bottom until the level is pure vertical. Record how far the gap is between the end of the level and the rim edge. Let's say for example, the top of level is 1/8" from rim.

With the distance between the contact points being 12 inches and the gap upper gap is 1/8", then the camber in degrees would be approximately 5 times the gap in inches in the negative direction (negative camber is top in).

To correct to desired values, note the tick marks on the camber cam bolt eccentric - a one tick change will change the camber by approximately 3/4 of a degree (.72 degree in the middle of the scale).

Hope this helps.

Bob Heine

Have you checked to see if the axle stub is coming out of the differential? The stub may do that if the retaining clip comes off.

Easy Mike

Not quite; do you have the camber ellipticals installed?

Trailing arm shims are for toe settings, not camber. Camber is set with the strut rods.

Did you jounce the suspension after you reset the camber? Chug it up and down the drive way or take it around the block, then check it again.

larrywalk

If the rims have a stock backspacing (~4 1/4"), you should be fine as the distance outward of a tire is a function of the length of the halfshaft. If they appear too far outward, you should compare the distance from the edge of the rear fender to the frame on both sides.

Scottd

Yes, I have the ellipticals installed. As I rotate those circles with the attached bolt, my camber changes. But I just cant seem to get it to the right angle. Its either all the way, one direction or another. Fine tuning it by small increments seems to produce little effect.

Bob mentioned a loose axle stub......would it be as obvious as just grabbing it and pulling to check? How much 'in and out' play should that half shaft have?

Garys 68

If your control arm bushings are ok, it's the axle stubs. Raise the rear, tighten the camber bolt, rock the wheel at top and bottom. There should be little or no in out movement of the axle stubs.

Bob Heine

Scott,
It's hard to see the stub but here are a couple of pictures where to look. There is a flange on the axle stub that should be very close to the differential. You'll be looking up into this area (on the other side, of course):


This is my differential after re-assembly so I know the axle stub is in the right place. Note that the flange behind the u-joint is tight up against the case -- if yours has a big gap, the clip is gone and the stub can move out of the differential.


If it doesn't move at all, you have a different problem but if it moves a quarter inch, I would disconnect the axle shaft u-joint and see if the stub pulls completely out of the case.

Mike Ward

Just in the interest of not chasing red herrings, the yokes (stub axles) can not cause positive camber as the OP describes. Negative camber would be possible if the yokes are heavily worn.

Stock tires on stock rims will never cause rubbing on the fender. Something else is going on.

Garys 68

I recall seeing a pic here where the stub was worn so far, the clip was gone.

540 vette

If everything is the same as before you put on the tire and control arms and you didn't have that problem before you did that work, there has to be something wrong in one of those 2 areas. Why would the side stub all of a sudden go bad.

69small block

ck out Dontuv they have an instruction sheet on that alignment 101

leadfoot4

On one hand I agree with what you're saying. However, the OP said he installed the "control arms", actually trailing arms, last year. Now, he's noticing a problem.

On a stock car, there's PLENTY of clearance between the tire and fender, with the tires well INSIDE the fender well. The OP is saying the tire is "a good inch outside the fender". To me, it appears that something is messed up BIG TIME, as that wheel/tire is about an inch and a half outboard of where it's supposed to be.

Playing with the camber eccentric will move the wheel about 1/8-3/16", IIRC. That certainly isn't going to make a significant dent in a 1.5" problem. Secondly, those strut rods eccentrics are there to set camber, not space the wheels in and out.....

OP, you have to do some serious inspection of your rear suspension, 'cause something's not right!

Garys 68

Or he replaced the tires due to excessive wear on the inside caused by excessive side yoke wear. Could not get the original strut rod to get the camber adjusted, so ordered new ones. I've seen people bend the lowers to get it pulled in far enough too. Then kept driving til it wore so far the clip suddenly came off causing the top of the wheel to pull out.
Naaaa, couldn't be, nevermind.

MotorHead

Usually if the strut isn't tightened enough the wieght of the car will cause the top of the tire to move in and bottom of the tire to move out and it can be quite a bit of an angle, happened to me after getting my Vette back from a "Vette Shop" when I first got it and the time I decided I would be doing all the wrenching on my Vette from then on.

I simply jacked it up and put the camber strut nut on the same as the other side and it's been that way ever since, and my tires wear even.

Once you jack it up and let it back down you have have to roll the car back and forth for it to settle. I use garbage bags on he floor of my garage so the tires slip on them and they end up at the correct angle.

To make fine adjustment you gotta drive it around a bit to let it settle back to where it is normally.

If the OP moves the top of the tire in and then tightens the camber adjustment nut he has to take it around the block, if it is safe but it seems to me something in the rear end is worn allowing the tire to move outbound too far.

Mike Ward

Yes, that's common. The top of the tire tilts INWARD in such cases

You're right, couldn't be. The yoke is loaded INWARDS with approx. 300 lbs of force.

The OP is saying the top of the tire is tilted OUTWARD.

billsfan

A stupid question, but... is the tire on the opposite side in too far from the lip? It's obvious something major is broken.

Garys 68

At rest I agree, it's going to push in. But I can assure you, driving will easily slide the yokes back and forth. Kinda feels like driving on ice when they shift.
Anything else allowing that much movement would be painfully obvios with just a glance under the car.
That is assuming someone who know what camber is, knows enough to diagnose a bent wheel, broken trailing arm, halfshaft, u joint, etc.
Of coarse maybe the guy drives like this and the whole center camber rod mount is broken.
I'm sticking with yokes. Final answer.