Please help me diagnose my steering wheel shimmy
 

Here are the known facts:
1) When driving from 5mpg-55mph the steering is ok but feels a little wobbly
2) At around 60-75 the steering gets violently wobbly
3) This does not happens every time I'm over 65 but most times
4) Sometimes when I hit the brakes a little it subsides
5) I do not think it is a wheel balance issue because I never saw any weights on that tire/wheel.
6) I took the tire off and tried turning the wheel by hand. It turns freely for about 75% of the rotation and then seems to grip on about 25% of the rotation making me strain harder to turn the wheel.
7) Recently when I first start the car and I put my foot on the break the brake pad sensor light goes on but it goes off when I release the brake and doesnt usually come on when I'm driving.

I'm planning on selling this car this month so I dont want to waste a bunch of money fixing the wrong problem. Other than this the car runs perfectly.
Please help me!

tires. out of round or out of balance

Really? Then why would the wheel turn funny even when I have the tire off? I took the tire off and just turned the wheel by hand. It turns freely for around 75% of the rotation but then grips the brake or something for like 25% of it. I was wondering if this was a brake issue or a rotor issue especially since the brake pad light comes on when I fist push the pedal down to put it in gear.

What does out of round mean?

When you say you take the tire off and turn the wheel I assume you mean you take the tire/wheel off and turn the rotor. This isn't a good test. Without the wheel the rotor is held on by only one set screw. To see if it's turning smoothly you have to put all five lugs bolts back in and torque them down. This requires five spacers about an inch long, or of course five shorter bolts.

Hi spree17, Id say its your wheel balance for sure.

Check your brake fluid, if its low thats setting your light off.
If it is its either you have a leak or brake pads are due.

Dont worry about the wheel grabing thats normal.

wheel balance
 

The wheel balance , even a tiny bit can be a bit vibation problem. Maybe a belt even broke in the tire, but mosr likey the tire just needs balanced, and you said you wanted the cheap fix to sell the car, balance the tire for $15 and see if it is the issue. Spinning the wheel or the rotor or the hub with the car up and the tire on or off is a hard way to test. THe unsrpung weight of suspension, no load on the bearings, the rotor not being lined up due to the one set screw, the brakes dragging, etc all give false readings. Good luck
I would balance the tire at a very high quality shop, preferably one that can balance the tire on a high speed machine that does it under a load, like a Hunter machine.
IF it is not the balance you are not out much and you can look at the brake rotor or the pads. Check your brake fluid level too.

#5 - A tire w/o a wheel weight sounds suspect to me.

I balanced a lot of tires as a kid and cant remember any getting NO wieghts. They usually got one on the inside AND the outside of the rim. If lucky, they only got one on one side.

They fall off sometimes.

Thanks for all the great replies. I meant I was turning the rotor with the wheel off. It grabbed about 25% of the rotation and spun freely on the rest. I also put the tire/wheel on and spun it. I could hear the breaks or something rubbing inside a bit when I would spin the wheel. This was with only that side jacked up on a jack stand. The brake fluid is fine. I have checked it several times. The brakes dont pulse or squeak or anything.
I have a spare that has a whole. I think this week I will have the spare patched and switch wheels. If that changes it than indeed the tire was out of balance. I just fear that its not a balance problem. I hope I'm wrong and you guys are right!

Spree17:

Does your car have a steering linkage damper? If so, a bad damper will cause just what you are experiencing (been there).

Also, of course, in addition to balanced wheels/tires you need to have good shocks, ball joints, suspension bushings, etc. If not it doesn't take much to cause problems like yours.

Cary

Try rotating the front wheel to the back and see if it goes away before spending any money. I find that most of the time the vibration is dealing with balance or a shifted belt in the tire. The times that I had problems after rotating the tires where almost always directed to something loose or worn on the suspension. Check the steering damper like Cary mentioned!!

the brakes dragging only part of the time sure seems like a warped rotor to me.

if not for that i would say tire balance most likely. out of balance tires are made more dramatic by loose front end parts. the tie rod ends seem to fail first on most benzes.

tom w

Hey guys thanks for all your help! Turns out you guys were right. It was the Tires not the brakes or anything else.

After checking the brakes and everything else myself I decided to get the spare which had a hole plugged and change it with my right front tire.
Then I remembered that the tires were bought at discount tires so I brought it there to get plugged since it should be under full warranty. I also asked them to balance the front tires also under full warranty. Turns out I was wrong about where the problem was. It was in the left front tire. It had a small bubble that I could not even see. I had them replace the tire under warranty and after declining new tires all around my car (Cost $441 for 3 with 1 free) about 5 times I was on my way. :)
I wish I did this 2 weeks ago. It would have saved me time and aggravation! :)

glad you got it figured out. Tires are funny creatures, but our MB car's will let you know when one has a problem every time. They dont like suspension and tire issues and they get amplified and compounded fast. But, that is why when all is working right, the ride is so enjoyable

I should have asked and listened to you guys weeks ago. Instead I wasted time and money thinking I knew better. :(

one more thing you need to think of,what speed rating do those discount tire have?It would be a shame to lose your car for a tire that will only guaranty 55 mph.JNT