steering and suspension Steering wheel shimmy at speed

[avoirdupois]

I'm having a hard time envisioning why a steering box would cause a shimmy.

 

 

The steering gear assembly would not cause a shimmy anymore than a loose tie rod or drag link joint.  Slop in those joints and steering linkage tends to magnify easily overlooked balance issues.  Conversely, when those joints and other steering parts are snug, they tend to dampen or suppress wheel, tire and/or brake oscillations.  Like you, I lean toward the shimmy being resolved by something other than replacement of the steering gear assembly, but if the wear or lack of adjustment is significant, it could make any shimmy more noticeable or intolerable.

 

I am sure there is another take on how a "tight box" could be related to shimmy, but that may be covered in a different chapter of the shop manual and require something other than GL5 hypoid lube..   Of course I meant a tight "steering" box. .

[Vicleonardo1]

Agree with Toby, could just be a bent wheel or a bum tire. Jack up the front of the car, turn the steering wheel all the way to the right so you can look at both the inner and outer edge of the right front wheel, then spin the right front wheel and look at both the wheel and the tire. Then turn the wheel to the left and look at the left front wheel. Even if you don't see anything, having a competent shop do a road force balance on the front wheels shouldn't set you back much more than an evening's drinking money at a club. I'd do that before dropping hundreds on the steering box. 

 

 

Jeez, Rob, we need to talk about your drinking problem. Road force balancing is not all THAT cheap. You may need to find a good discount liquor store and try staying at home. Stow the money you save away in your IRA.

Please give a toast to me at your retirement party. 

 

Cheers! 

[dpowell]

Alright. So many of you are saying I may have been justified in my suspicion about my mechanic's steering box diagnosis. I I think I'm just going to limp up to Casey Motorsports in the near future and make sure this is taken care of correctly.

 

Thanks, again.

[adawil2002]

Alright. So many of you are saying I may have been justified in my suspicion about my mechanic's steering box diagnosis. I I think I'm just going to limp up to Casey Motorsports in the near future and make sure this is taken care of correctly.

 

Thanks, again.

 

Tom Jones will get it all resolved, please keep us posted. Interested to know what he finds.

[freedo]

i didnt read everyone reply but i had the exact same issue in my car.  the moment i went above 65mph and held it at a constant speed the steering wheel and car would shake like crazy.  if i was accelerating past 65 it wouldnt be as noticeable until i tried to maintain that speed.  i lived with it and eventually replaced my worn out rear tires with new ones and a fresh rebalance.  the car can now cruise at 70-80mph with only slight vibrations (i know i have bent wheels and unbalanced snow tires on the front causing this).  instead of checking the steering box id first get your wheels freshly balanced and road force balanced if possible.  if its still there i would see if i could borrow a spare set of wheels and tires to see if the problem goes away or not.  if it still doesnt go away id check the driveshaft balance, bushing and make sure its all tight.  

[dpowell]

Update:

(long overdue, for those of you still following)

 

Finally got the car to the shop. I couldn't find the time to limp all the way to Petaluma and see Tom Jones et al at Casey Motorsport. I will find an excuse to visit that shop soon, I'm sure. Instead, I hit up Bimmers Independent in San Carlos. I'd already picked up a cleaned/resealed steering box here on the FAQ from dar_on, so I brought that, along with some GL-4. Once on the rack, they seconded the steering box diagnosis, so I let them know I had a replacement in the trunk, and they cranked out the replacement.

Verdict: NO SHIMMY!

I'm very pleased with their work. They didn't over-tighten the box (still threads left for the future), but the steering is definitely tighter than it's ever been. And with the shimmy gone, I feel confident at highway speeds, again.

 

Thanks again to all of you for your input. Special thanks to dar_on for supplying a quality box. And if any of you need the occasional professional wrench on the Peninsula, I can report at least one very positive experience with Bimmers Independent.

[ray_]

Cool. Great to have it back at 100%!

 

I've never heard of that particular fault before.

 

Cheers,

[jgerock]

Glad Daron helped out with the replacement steering box. I was betting on the loose wheel bearings.  BTDT.  I had to adjust mine at a rest stop in TN on the way to MidAmerica in 2010 and again after the Autocross session at Vintage.  I recently replaced them since I thought they were suspect.  Having 14" wheels, wider tires, smaller diameter steering wheel and slightly modified suspension seems to amplify small issues.

[silasmoon]

On 2/8/2016 at 3:31 PM, fwardell said:

Sounds like a problem I had recently. Turns our my cheap Chinese 13" tires were out of round. Went to a tire truing outfit - worked great. Then, finally got a set of decent tires - Michelins.

What Michelins??