Suspension clearance problem

[Matt_West]

Today I figured out the source of an unhealthy and unwelcome noise that has been troubling me. The noise is an intermittent groaning vibration when the steering wheel is held just off center. It started right after the installation of some 8 inch welded Fuchs with size 225/50/16 tires on the front. I almost never hear the noise at speeds greater than parking lot velocities.

The source of the noise appears to be contact of the inside front drivers side tire with the body of the shock. The car is a 1980 sc, the shock is green in color, and the top half of the shock body is larger than the lower half. The tire is contacting the top part of the shock body causing this sleeve to rotate. I do not appear to have this problem on the passenger side.

The two obvious solutions might be:
1. Move the top of the shock in board.
2. Install a very small wheel spacer.

I am uncertain how much latitude I would have with option one, and what the effect on the alignment might be.

I am not enthusiastic about option two as the tires were a very tight fit and I already had to roll the fender a little.

Has anyone experienced something similar? or are there any recommendations on remedies?

[Walko]

Matt,

Before you do that I would suggest that you change your left front tire to the right front and right front to the left front. I would do this to ensure that the wheels that are welded have the same back space. If the wheel which is rubbing on one side starts to rub on the other side then you need to start measuring the rims.

Manufacturing tolerances aren,t always what they should be.

My thoughts

Michael

[Matt_West]

Thanks for your advice. I jacked up the car and took off both front wheels. I prefer not to swap sides as the tires are directional, so I elected to go the route of very careful measurements.

To get the measurements I laid a straight edge across the back of the tires and measured to the flats that mount against the hubs. I did this many times per wheel and can discern no difference between the wheel tire combinations.

Here is a picture of the problem side:

[Tyson Schmidt]

Just remove it altogether. That's what all us racers do.

Or, you could just cut off the the lower portion, leaving the upper 2 inches or so. That's what I did on my Koni struts, since they have an external bump-stop and I needed to leave the upper portion to contain it.

Your Bilsteins have an internal bump-stop. But it may be smart to leave the uppermost portion to interact properly with the upper strut mount rubber.

[Matt_West]

Thanks for the reply.

If I trim the sleeve that is making contact what is underneath it?
Are there any negative repercusions?
Does anyone have a picture of a trimmed strut?

Thanks again for the help.

[Jason Porter]

The strut rod is underneath it, cut off what you don't need, and take off some extra so when the strut compresses the edge won't mangle the tire...

[don911]

What's that rub on the body just to the right of rotor in your pixs? Is that down to metal?

[Jeff Alton]

Inside of tire at full lock, I think.

Cheers

[Jason Porter]

What size wheels/tires are you running? Do you have a measurement for the actual backspacing of those wheels?

[Jeff Alton]

I think he said 16x8 welded fuch with a 225/50/16 tire. But no mention of offset/backspace.

Cheers

[bkreigsr]

you could also use some spacers. there was a pelican selling custom laser cut alum spacers 1/8" wide on the fs board about 2 weeks ago. you could probably stack them to get the spacing you need.
ths top tube is just a dust cover and can be removed with no ill efffects
Bill K

[Zeke]

Originally posted by Matt_West


The two obvious solutions might be:
1. Move the top of the shock in board.
2. Install a very small wheel spacer.

I am uncertain how much latitude I would have with option one, and what the effect on the alignment might be.

I am not enthusiastic about option two as the tires were a very tight fit and I already had to roll the fender a little.

1. The spindle will move with the strut; no gain.
2. I agree that what you gain on one side , you lose on the other.
So, 3. Add the spacer and raise the car a bit.
4. Check for bent spindle.

[Chuck Moreland]

Milt may be onto something with the bent spindle idea. This would explain the why left and right behave differently.

For the inner wheel well rub, this is not due to the spindle.



A "Tire Rub Prevention Kit" will prevent this, available here:
http://www.pelicanparts.com/catalog/shopcart/911M/POR_911M_SUSstr_pg3.htm#item12

[Matt_West]

Thanks for all of the replies. I am not certain of the back space. The fronts are 8X16 welded by a guy in Colorado. Mark Wilson might recall the spec.

The circled scratch is tire rub at full lock. Yes I need the kit, but for now I am trying to remember not to use full lock as I leave the carport...

I am not certain how to check for a bent spindel. I am really reluctant to modify the strut, but recognize the responders as trusted sources.

I will take another look in the next couple of days and let you know what I end up doing. What is clear is that something needs to be done.

[Jeff Alton]

Matt, if these are the ones that Rdane and Mark Wilson had made, I used to have a set. The ones I had are now owned by Gary (arcsine) on the board. The ones I had did have a 3mm? (small) spacer fixed to each one with a couple of set screws. I did not have any rubbing issues with them, even when I went to coilovers.

Cheers

[Matt_West]

Thanks Jeff. These are the same wheels.

Gary would you be kind enough to post a picture of your spacer setup?

[Matt_West]

Pelican does not appear to have 3mm spacers... does anyone know of another supplier?

[dentist90]

Another, less desirable, solution might be to go narrower tires... say 215/50/16? I guess there's no room between fender and tire for a very small spacer?

[don911]

I got some 5mm spacers from Fordahl a couple years ago. He may be able to get 3mm spacers, or have them made.

[rusnak]

Note to self: no jokes about angering the Porsche gods in front of all these nice people.......