tsmathers

I have a '97 993 TTS, orig owner.
Upgraded to BBS wheels shortly after purchase w/no problems. Car has ~35k m and has developed a steering wheel vibration/shimmy at 60mph +/- 5mph.
Did all the usual stuff: rebalance everything, put the orig wheels back on, etc w/no change to shimmy.
Not affected by brakes/no brakes, in gear, any gear, neutral, clutch in or out, under power, coasting.
Checked wheel bearings, brake rotor runout; all ok.
Only happens at ~60mph.
Before I start throwing money and parts at this, any ideas of what to try next??
Inputs appreciated
Thx

jimhsu

welcome tsmathers....

you are an original owner of a 1997 TTS and NOW you appear on the forum?? What took you so long?? You have a nice ride.

I will leave the answers to those with smarter p-car brains, but....we're gonna have to see pictures of your car for proof that it exists!

ScottMellor

I have recently learned from Mike Lederer that that particular shimmy can be cured by new suspension bushings.

pstoppani

I've had the same issue. I found that indexing the wheels fixes the problem. By "indexing", I mean "take the wheels off, rotate each wheel clockwise by one lug bolt, put back on, test drive, if still get the shimmy, rotate wheel clockwise by one more lug bolt".

When someone suggest this to me when I first started having the problem I thought it was a complete joke. I spent a bunch of money rebalancing, replacing parts, to no avail. Out of desperation I tried the indexing, and bloody hell, it worked!

pstoppani

Is it because of age-related deterioration? His car has only 35K miles on it! Mine started doing this at about the 38K miles.

Any specific bushings or OEM?

Thanks!

C.J. Ichiban

suspension parts with rubber in them eventually dry out, crack, and cause small irritating issues like these- that's why during a ppi the mechanic usually goes right for the shocks, bushings, etc.

chris walrod

Here is a thread I started last week on replacement urethane suspension bushings. I have replaced suspension bushings on a really clean 29K mile 993 that showed signs of cracking. It happened to cure the random steering wheel shimmy that so many of these 993's are effected by.

tsmathers

Thx to all for the quick responses.
I will look into the bushings.

This is much better than throwing shocks and all the other BS inputs I have gotten at the problem hoping for a miracle.

BTW: in case I am not the last person on the planet to learn about it, the only other problem I have had w/this car was after ~20k miles, I would get lots of smoking at startup that would go away after 10-20 secs. All the dealers acted like they never heard of the word "turbo" so I lived with it until I discovered the turbo oil line check valve retro-kit from Turbo Kraft. This absolutely eliminated the problem entirely. Pretty painful to install w/the engine in the car but worth the effort.

Thx

AndyT

I replaced my lower control arm bushings with ERP monoball inserts after almost eating the armco at Watkins Glen multiple times. Basically the tow setting was constantly changing due to the cracked old rubber inserts as CJ mentioend. You can also replace the entire lower control arm with the RS part which has stiffer inserts but not monoballs. Good for a street / track car

chris walrod

I have been told the RS arms only differ in that aft bushings are stiffer -- the front 'compliance' bushings is the same for RS and ROW cars.

Wonder if the tire companies sponsored the 'cavity bushing campaign' by Porsche to accelerate the wear of tires..... Pirelli-gate?