steering wheel shimmy

[jiggysubman]

I've got a pretty bad steering wheel shimmy starting at about 50mph, and getting worse as speed increases. What are possible causes/fixes for this? Any help would be appeciated.

[RandallNeighbour]

wheel balancing is your culprit. I've got it too after FIVE trips to discount tire, last of which was a "road force balance" job on all four wheels, which is what you should find.

If you can find a local speed shop that specializes in balancing wheels on cars that are driven over 100 mph, that's where you should take it.

Boxsters seem to have this problem frequently and keeping the wheel from jiggling is going to be one of those things you'll work on a lot. You'll also learn to determine the difference between road feel and shimmy due to an unbalanced wheel.

[Brucelee]

Randall is dead on. Find a first class shop.

Hey jiggysubman, when you get this problem resolved, you might need to change your screen name! Maybe to....smoothsubman!

[prOk]

Heh.. I had the same problem. I took it to all the usual tire places and had their 'best' balancing job done and could never get rid of the shimmy. Wound up finally breaking down and took it to the dealer. Their tire guy balanced them smooth as silk, I mean, zero shimmy. 49 bucks well spent in my opinion.

/b

[deliriousga]

Originally Posted by jiggysubman

I've got a pretty bad steering wheel shimmy starting at about 50mph, and getting worse as speed increases. What are possible causes/fixes for this? Any help would be appeciated.

For future reference, if it starts at lower speeds and/or in the steering wheel is usually the front tires. Higher speeds and/or in the seat is usually the rear tires.

How many miles do you have on her? If balancing doesn't take care of it and you have a pretty good amount of mileage, check the ABS sensors to make sure they're not caked up with metal brake flecks. That keeps them from feeling the wheels moving then they think "holy cow, he's doing 90 and the wheel is locked up" and start fluttering to release the pressure. That one gets violent when the speed gets up there.

[jiggysubman]

Originally Posted by deliriousga

How many miles do you have on her? If balancing doesn't take care of it and you have a pretty good amount of mileage, check the ABS sensors to make sure they're not caked up with metal brake flecks. That keeps them from feeling the wheels moving then they think "holy cow, he's doing 90 and the wheel is locked up" and start fluttering to release the pressure. That one gets violent when the speed gets up there.

i've got 81k on my 97. Perhaps i should look intot this being the problem as well. The drivers side of the car shakes as well starting around 80. Can you tell exactly where to look for these metal brake flecks?

[deliriousga]

Originally Posted by jiggysubman

i've got 81k on my 97. Perhaps i should look intot this being the problem as well. The drivers side of the car shakes as well starting around 80. Can you tell exactly where to look for these metal brake flecks?

When you take the wheel off, there is a sensor for the ABS that plugs into the top of the steering knuckle. It is held in with one screw. The sensor goes through the knuckle with the bottom exposed just above the teeth on the axel. The sensor uses a magnet to sense those teeth moving past it. Since brake pads are "semi-metalic", some of the brake dust collects on the magnetic end of the sensor. Over time it can cover it with dust so the magnet in the sensor feels the dust sitting still and can't feel the teeth moving through that dust.

Unscrew the sensor and twist it lightly to slide it out. Be careful not to twist it too hard because you can break the sensor (I had a mechanic do this once and found out when the brakes let go. ) When you put it back in, put some anti-sieze on the sides of the sensor, but make sure you don't get it on the end where the magnetic feeler is.

[jiggysubman]

Originally Posted by deliriousga

When you take the wheel off, there is a sensor for the ABS that plugs into the top of the steering knuckle. It is held in with one screw. The sensor goes through the knuckle with the bottom exposed just above the teeth on the axel. The sensor uses a magnet to sense those teeth moving past it. Since brake pads are "semi-metalic", some of the brake dust collects on the magnetic end of the sensor. Over time it can cover it with dust so the magnet in the sensor feels the dust sitting still and can't feel the teeth moving through that dust.

Unscrew the sensor and twist it lightly to slide it out. Be careful not to twist it too hard because you can break the sensor (I had a mechanic do this once and found out when the brakes let go. ) When you put it back in, put some anti-sieze on the sides of the sensor, but make sure you don't get it on the end where the magnetic feeler is.

this may be asking a lot but does anyone have a picture that points to this sensor, or shows the general area? I'm looking at taking off the wheel today.

Tools Pants will probably be sending a picture any minute now!