: Front End Shimmy



Tug Boat
07-07-09, 12:26 AM
I have an 03 EXT with a shimmy in my front end that feels like out of balance tires. Tires have been recently balanced so I know that isn't the problem.

The mystery is the problem isn't constant. Can drive the same road in the morning and have a shimmy, drive it later that day, or the next morning, and no shimmy. When I turn off the stability control the shimmy lessens. If I stop and start again with the stability control off, the shimmy is gone, usually.

Any suggestions what it could be?

luxurylife33
07-07-09, 12:38 AM
What do you mean "shimmy"?

Tug Boat
07-07-09, 12:42 AM
What do you mean "shimmy"?

Sorry, shimmy must be a Canadian word. I mean an up and down vibration in the front wheels you can feel in the steering wheel, and at 50mph, can feel in the cab. Vehicle still steers and tracks fine.

luxurylife33
07-07-09, 12:48 AM
only when your braking? warped rotors
while vehicle is in motion? most likely wheel bearings

The tires can not be the problem, as it would be constant and not sporadic.

Tug Boat
07-07-09, 12:54 AM
only when your braking? warped rotors
while vehicle is in motion? most likely wheel bearings

The tires can not be the problem, as it would be constant and not sporadic.

I appreciate your input. The problem isn't when I brake. Wheel bearings maybe, but why would turning off the stability control stop the vibration.

luxurylife33
07-07-09, 10:03 AM
I appreciate your input. The problem isn't when I brake. Wheel bearings maybe, but why would turning off the stability control stop the vibration.

it might be one of those psychological things where you think its less noisy? or is it noticeably quieter?

Rolex
07-07-09, 11:23 AM
Bad tires would be my guess. Rotate the front tires to the rear and see if that makes a difference. How old and how worn are your tires? Also, I know from past experience if you let your vehicle sit for very long the tires can develop flat spots. When you first drive the vehicle you'll experience a front end "shimmy" or vibration. After you heat the tires up a little the flat spots will come out and the vibration will improve. Just possibilities.

Povich
07-07-09, 06:31 PM
you have aftermarket wheels? Oversized? Roadforce balance them! Sounds like slightly out of balance wheel to me as well!

Tug Boat
07-07-09, 10:33 PM
you have aftermarket wheels? Oversized? Roadforce balance them! Sounds like slightly out of balance wheel to me as well!

I have Cadillac 20" rims with Michelin LTX tires. It certainly feels like an out of balance tire, but if this was the case, I would expect to feel the vibration most of the time I drive. Today's driving, no vibration. It's the randomness that makes this problem perplexing.

Appreciate the suggestions and will keep researching. May end up having to go to the stealership.

Povich
07-12-09, 09:18 AM
if you have two or more that are ever so slightly out of balance, and they get in sync just right youll feel the "shimmy" more! Id bet you need them balanced and find a shop that has a http://www.gsp9700.com/index.cfm! Well worth the money IMO!

05Yukon
07-14-09, 01:49 PM
Might be the front shocks. Might want to have your autoride checked. When my front shocks were shot i was getting some bouncing in the front end on the high sometimes but not all the time.

hcvone
07-14-09, 04:20 PM
How many miles on your truck? Could be the steering box gears showing wear, it's been a while since I had my 03' :hmm:

Tug Boat
07-14-09, 09:16 PM
Might be the front shocks. Might want to have your autoride checked. When my front shocks were shot i was getting some bouncing in the front end on the high sometimes but not all the time.

Good suggestion, I will check it out. Your symptoms sound similar to mine. Thanks.

Tug Boat
07-14-09, 09:20 PM
How many miles on your truck? Could be the steering box gears showing wear, it's been a while since I had my 03' :hmm:

60,000 miles. It still tracks and steers very well, even with the vibration, so it makes me think it is something other than the steering gears. Appreciate the suggestion though.

CaddyMax23
02-16-10, 04:49 AM
Did you ever solve this? My 2009 has the same issue. It is not the wheels, it is not the tires, it is not the balance.
Sometimes when I go over a bump on the freeway, the shimmy starts. Sometimes I can drive 50 miles with nothing.
Must have something to do with inadequate control arms or something.
Suggestions? It is very irritating.

Max

maxh1@cox.net

2009 Escalade, lowered 2.5 all around, dropped spindles, Magnaflow CatBack, Magba Charger blower - outting out close to 600HP. Awesome machine apart from some quality issues that should not exist for an $80K vehicle.

Rolex
02-17-10, 06:50 PM
Raising or lowering the vehicle changes the steering geometry. Did your truck shimmy before you lowered it?

Tug Boat
02-18-10, 12:53 AM
Did you ever solve this? My 2009 has the same issue. It is not the wheels, it is not the tires, it is not the balance.
Sometimes when I go over a bump on the freeway, the shimmy starts. Sometimes I can drive 50 miles with nothing.
Must have something to do with inadequate control arms or something.
Suggestions? It is very irritating.

Max

maxh1@cox.net

2009 Escalade, lowered 2.5 all around, dropped spindles, Magnaflow CatBack, Magba Charger blower - outting out close to 600HP. Awesome machine apart from some quality issues that should not exist for an $80K vehicle.

The problem went away on its own and hasn't come back. Though after one of my tires went flat to the rim from a slow leak last December, I do have a slight vibration at 60mph. If you have GM OEM chrome rims, keep an eye on your tire pressure. It is only a matter of time before they start to leak.

I did read in an Avalanche forum where a similar problem was diagnosed as a sensor that was getting wet and malfunctioning.

Sounds like otherwise you have an awesome truck. Imagine with all that HP, you spend a lot of time at the gas station. ;)