Loose-feeling shimmy in the front (not warped rotors)

[211]

I noticed this when I first got the car (3rd owner) but it's slowly getting worse; when I brake there's a shimmy in the front. I know it's not the rotors because I can feel the "clunky looseness" when I go over a bump, hit a driveway at an angle, or hit a pot hole. The shimmy under braking is transfered up through the steering wheel so I can feel it there too. It feels like tie rod ends or something because this used to happen to my Yukon all the time.

 

I'm wondering if this is a backyard mechanic's fix or is this something I should take in and have Les Schwab do. What could it be? Tie rod ends I could probably do, idler arms, linkage or struts I'll probably have to take in since time and tools don't really allow that sort of fix for me.

 

Oh, 2000 OBW just rolled 93k miles

[idosubaru]

you can do just about anything up front, it's all easy on EJ vehicles. rusted bolts are the only annoying part but yours is new enough that you shouldn't have much of that.

 

how about the axles, have those ever been replaced? i would expect them to make some kind of vibration on acceleration though too.

 

tie rods, ball joints, and strut mounts/strut bearings are the only things i can think of.

[211]

you can do just about anything up front, it's all easy on EJ vehicles. rusted bolts are the only annoying part but yours is new enough that you shouldn't have much of that.

 

how about the axles, have those ever been replaced? i would expect them to make some kind of vibration on acceleration though too.

 

tie rods, ball joints, and strut mounts/strut bearings are the only things i can think of.

 

No vibrations under acceleration, just while braking- and its most promenent between a certain range like 45-35 mph

[Gloyale]

Have you inspected the rear rotors??? Actually pull them off and inspect BOTH sides.

 

I know the vibration is in the front, while braking. But I have seen before where rough rotors on the rear caused bad jerking vibration of the whole car. And the OUTER side of the rotor appeared fine. Took it off and inspected the other side.....Yikes:eek: The salt and moisture trapped between the rotor and backing plate caused the rotor to corrode, and actually flake off large pieces.

 

The knocking over bumps could be tierods or balljoints. Rattling over bumps sounds like it. Unrelated to the cause of the braking vibration, but amplifying the vibration during braking.

 

Just a suggestion to have ALL the rotors inspected, not just the front.

[aircraft engineer]

pedal pulsation would be a warped rotor.

 

Your shimmy might be a set of well worn pads. Not worn down enough to make contact. Normally, brakes will "stop" front end shimmy when they are applied (at least in my experience)

[211]

I'm dismissing the brake theory because the guy had the brakes done just before I bought it (and I noticed the clunky front end during my first test drive). I saw the reciept, 4 new rotors, new pads etc. the whole bill was for the 60k service interval, brakes included. The whole bill was like 3 grand

[aircraft engineer]

any indication of strange tire wear?

 

How about a particular speed that it happens and then goes away? That kind of indication would be tie rod ends worn.

 

Hoist it up and check them and see if they move "excessively".

 

Is the alignment in? Shocks (struts) OK?

 

Aside from suspension, there isn't much else except for a bad wheel balance that causes that kind of indication. Bent wheel? Try swapping fronts and rears and see what happens. Check every bolt and nut in the front and see if they are tight. Bent axle?

 

Not much else out there Try a "hands off" stop and see if it steers funky. About the only other thing I've seen is chill spots on the rotor that cause a grab/release.

[2X2KOB]

I predict this will end up being sticky gunk residue on the front rotors. Take them off and clean them with steel wool and brake cleaner spray and see if that makes a difference. This fix attempt costs about $3.00.

 

-2X2KOB

[davebugs]

Just a thought. Just cause they were new rotors doesn't mean that they were any good to begin with. Or that now that they are 'worn in' problems can't start.

 

I wouldn't be so quick to rule out rotors - or rotor issues because of the pads, brakes sticking (didn't lube slides, etc.).

 

The clunking is a different issue I suspect. You're just trying to tie them both together since you noticed them both and they both are part of the front end.

 

That's my theory.

 

Dave

[Gloyale]

I saw the reciept, 4 new rotors, new pads etc. the whole bill was for the 60k service interval, brakes included. The whole bill was like 3 grand

 

You say the car is now at 93k miles? That means 33k miles on the brakes. Sounds like worth at least pulling the wheels and inspecting. But suit yourself, and dismiss all you want.

 

However, I have found over the years that if the problem(vibration) occurs when you apply the brakes, 99% of the time it's related to the brakes.

 

It can't hurt to have all the front end suspension bits checked, but my money is on the rotors.