Rear wheel adjustment and alignment question/issue...

[Todd Simpson]

You can not just start messing with toe and camber...you can easily create some dangerous handling combined with extreme tire wear. Adding negative camber increases toe out for example, and toe out in the rear will be rather "interesting".

If you have a string alignment set up and some basic skills you can align the suspension yourself but it takes time.

Those appear to be fuchs replicas, but they also appear to be in a stock size with stock size tires. Nothing should be rubbing.

It does appear to have positive camber in the rear and that could be your problem...either that or a bent control arm. I realize you measured a difference in camber, but keep in mind your floor may not be level.

Finally...a shop dedicated to old Porsches needs to do the alignment. Alignment shops will be completely useless, and even good mechanics of other brands will be puzzled by those alignment eccentrics....they really are unique to Porsche. They can also be frustrating as hell to adjust.

[rusnak]

I'm just guessing, but I think with the positive camber and zero or no toe that 185 shod 911 could be all over the place already.

[Todd Simpson]

yeah, could be!

I like a little rear toe in.

[Flieger]

I meant the banana arm, not the spring plate. The steel bananas can bend without breaking in an impact.

You cannot rely on measurements from wheel to body panel for alignment since most cars have slightly mis-aligned body panels due to the large amount of manual labor in building the cars.

[hessel1974]

I agree that the car needs to be aligned properly. But I can't drive it now without the risk the tire rubs against the fender.

I get a tire change (shop owner is a fellow 911 driver) somewhere next week and i'll ask if they can check toe when doing it. But I need to change things now to even get there.

Garage floor is level, so using the method described should be more or less accurate. Toe for a '71 2.2 is zero degrees, so no toe-in at all. Does this make the car more nervous?

Finally, what is the correct sequence? First Camber and then Toe or the other way around?

Thanks!

[Tim L]

Yes, camber then toe then check camber again. I use a laser level attached to a bar placed on the rim to check toe its very accurate.

[Todd Simpson]

The Scruggs book recommends doing toe last...If camber is off a little you're OK but toe needs to be spot on. One does effect the other.

If you search on "scruggs" you can find references on his little book, which is a great tutorial on home alignment.

[hessel1974]

Ok, I started today with "mending" the positive camber on the right rear wheel. I loosened the 2 bolts which holds the springplate to the banana arm and both the camber and Toe eccentric.

When turning the Camber eccentic, only a very slight movement was noticable in the wheel, not nearly enough to get a negative camber. I have tried different things, top bolt tight and lower loose, the other way around, but to no avail.

When I was at the specialist last week, he was able to get a lot more movement in the wheel and get it negative. What am I doing wrong? Should the toe in eccentic be tight before attempting the camber eccentric?

Also, how does the eccentric bolt work? what does it do when you turn it so that it tilts the banana arm? Just cant figure that one out.

Thanks again for you help!

[Trackrash]

When turning the Camber eccentic, only a very slight movement was noticable in the wheel, not nearly enough to get a negative camber. I have tried different things, top bolt tight and lower loose, the other way around, but to no avail.

When I was at the specialist last week, he was able to get a lot more movement in the wheel and get it negative. What am I doing wrong? Should the toe in eccentic be tight before attempting the camber eccentric?

Also, how does the eccentric bolt work? what does it do when you turn it so that it tilts the banana arm? Just cant figure that one out.

You may want to take out the camber adjusting bolt and make sure it is not damaged and it is in the correct orientation. It is possible to have it in upside down. The toe bolt can be left tight, but you may want to loosen it to see if that helps. Check to see if the banana arm is moving on the torsion arm and is not frozen due to rust. You could remove just the camber bolt on the other side to see how it is oriented for comparison.
Have you had the rubbing issue before the alignment? It is possible that the banana arm is bent. They can be straightened in a press by a knowledgeable mechanic.

Toe for a '71 2.2 is zero degrees, so no toe-in at all. Does this make the car more nervous?

True the "specs" are zero toe at the rear. Most will recomend about 1/8" total toe IN at the rear, however, to make the car more stable. Zero toe or toe out at the rear can make the car scary if you lift in a corner.

[hessel1974]

Ok, I had the Swing plate seperated from the banana arm, had both of the eccentric bolts out, cleaned everything and lubed the bolts. Put everything back in place and tried again. No real change, still postitive.

When trying this, should the car be under it's own weight? I am tring it now without the wheel on and off the ground. Or shouldn't this matter.

The only thing I can think of next is a bend banana arm. But I have not done anything to bend it. Anyway, i'll give it another try tomorrow and see what happens...

[tobluforu]

Any checking of alignment is done with the full weight of the vehicle on the ground, swaybars disconnected if possible.

[rusnak]

Originally Posted by hessel1974

Ok, I had the Swing plate seperated from the banana arm, had both of the eccentric bolts out, cleaned everything and lubed the bolts. Put everything back in place and tried again. No real change, still postitive.

When trying this, should the car be under it's own weight? I am tring it now without the wheel on and off the ground. Or shouldn't this matter.

The only thing I can think of next is a bend banana arm. But I have not done anything to bend it. Anyway, i'll give it another try tomorrow and see what happens...

For the eccentric bolts to move the banana arm, the springplate (radius arm) and the banana arm have to be held together by the attachment bolts. Try tightening them to squeeze the two arm together, then loosten slightly to allow movement. The eccentric bolts will now move the banana arm quite a bit.

Try putting a dab of paint on the eccentric bolt lobe in order to not lose the orientation, and you might even grease the radius arm where it slides against the banana arm.