Wheel shakes past 50 mph

[joelnturkette]

I just bought a 1996 Subaru Impreza L and the wheel shakes past 50 mph. I took it to one mechanic (has notoriously high estimates) and they say it is the power steering rack. Has anyone known a power steering rack to fault on a subaru? Otherwise everything is in great condition, especially considering the age.

[Suzam]

WELCOME TO THE BOARD!

 

Have you tried tire rotation to see if it helps or changes the problem?

 

Warped rotors can cause vibration and shaking also. Does it vibrate when the brakes are applied?

 

Also a weak front strut could cause a problem with a slightly out of balance tire.

 

You didn't note the mileage, but it could be a badly worn steering parts as diagnosed.

[Fairtax4me]

I'd try getting the tires balanced first.

Worn inner tie rod ends are common on these because the dust boots will crack and allow dirt/dust in which wears out the joint. Those tend to make a fairly noticeable clunk over bumps.

[94Loyale]

+1 with Fairtax, 9 times out of 10 it's tire balance, tire pressures, or inner tie rod end. Most likely not the rack. Sometimes the tie rod end won't make a sound. But jack up the front end and shake the wheel from side to side, that's where you will feel the play on a tie rod end. If you feel anything loose, have a friend shake the wheel for you and at the same time put your hand on the inner tie rod. Then you can feel the play through the tie rod.

[Rooster2]

+2 on getting the tires balanced. Also, look at the front tires to see if they are worn evenly. If they have been out of balanced, and driven for many miles, the tires will develop "cups" or scooped out areas from bouncing around. If so, new tires will be needed to fix the problem.

 

Highly doubt the steering rack has anything to do with this problem.

 

As others have written, loose/worn tie rods can allow the wheels to shake. Check for that too.

[idosubaru]

Wheel seems like a likely place to start. Steering racks are almost unheard of failures on Subaru's. He's probably used to american cars. :lol:

 

Check that there's no dirt/mud packed up in the wheel, that will artificially imbalance it.

[edrach]

What's the mileage on your L? I have a '97 Impreza L which is my daily driver and I've been active in rallycross with it for over 5 years. I'm approaching 195K miles with it and there's no sign of an issue with the steering rack.

 

Start with the simple (i.e. less expensive) things like wheel balance, tires and the wheels themselves. After that other suspension related things.

[Allpar Mod]

As seems to be the case once again here, you're getting good advice.

 

ALWAYS, ALWAYS, ALWAYS diagnose problems by the K.I.S.S. principle. Simply stated it is...

 

KEEP

IT

SIMPLE,

STUPID! (No personal reference to you or anyone else here intended.)

 

It's often suspect when a problem goes from nothing to a big something immediately. A shop makes more on a steering rack R&R than on balancing 4 tires. I tell people all the time to look at the most obvious and simplest possible solutions and go to the more complex (and expensive) if they don't pan out. You usually don't have to throw parts at simple solutions, at least not as often as the more complicated ones. A good rebalancing every so often is a good thing to do even if it doesn't fix your problem right now. It won't be wasted money.

 

Wheel shaking at speed is usually related to either or both tire issues and brake rotor warpage. I had a bad shake started not long ago on my '99 OBW and balancing and rotation corrected the problem. Go that way first. If you feel pulsation in the brake pedal on applying them, have the rotors cut or replaced also. Warped rotors will cause a shimmy at highway speeds. The worse the warpage, the worse the shimmy. Bent rims cause shimmys. Have you nailed a curb or big pothole recently? If the tires are fairly old, it's always possible that there could be some cord separation causing the problem which cannot be fixed. This mostly occurs with steel belted tires. Suspension problems causing shaking are most often related to ball joints and other components like idler arms and tie rods, not so much a rack, though I guess it is possible.

Edited September 22, 2010 by Allpar Mod

[bstone]

Sway bar links.

 

They cause vibration at high speeds.