front end shake @ 55-65 mph
 

Hello all! I have my beloved wagon. Today I replaced the steering damper and checked the torque on the wheel bearings (12 lb/ft). Friday I had the wheels balanced and they said that the tires are good. I hopped in to take my wife to the movies (Starsky and Hutch, for the Torino) and it came back, only not nearly as bad. The shop also told me that the front end looked tight to them. I tried the 4 p's earlier and all appeared well to me. I need some ideas. Im almost thinking that its the ball joints. Straight line driving, I get "the shake" at 55-65 mph. When going around corners and such, "the Shake" disappears. This is what keeps me up at night. Any tips, help, ideas, sugestions, anything would be of great help. Thanks in advance.

D. Herman

1990 300TE
1993 300SE
1994 Chevy S-10 (Wife's Truck)

It could be the drag link. I had an intermittent vibration that would go away when I changed lanes. Grab the drag link (the steering damper bolts to this) and check for play. There should not be much.

Since you've already checked to see that everything is tight, I think it's time to swap tires front to rear and then drive it to see if the problem remains.

A very high percentage of such problems trace back to tire/wheel problems. Remember the SOURCE of vibration has to be something that rotates, loose linkage, bad shocks and things such as that only AMPLIFY such vibration, find the source first.

Even though the wheels were balanced, there still could be wheel/tire related problems such as a broken tire belt, a stiff spot in the tire or a bent wheel. Swapping them front to rear is the quickest and most positive way to check.

Hope this helps,

My car also had an intermittant vibration,,, it took the dealership 4 times to align the damn car correctly,, WHAT A PAIN...

the drag link? could it be any bushings? and this isnt hurting much, i need to do alot of freeway driving.

Any play in the steering can cause a resonate vibration. For some reason they always seem to come at those speeds. The act of cornering forces and holds the play to one side and deminishes the resonance.

The 124 car has good control arm bushings. If you were talikng about a 126, 140, 202, or 210 chassis I would blame the lower control arm bushings as they are pattern failures.

so then it would sound like a drag link to you? i hope i can find one on sunday!

Your original post suggested that the front end had been checked for play. Based upon that and that we are talking a 124 car (I think) I had no recommendations.

A drag link should be one of the easier forms of play to check. I wouldn't think they would miss it if play was checked for. Something has to give.

Re: front end shake @ 55-65 mph
 

Front wheel bearings should not have preload. They should have free play. The W201 spec is .01 to .02 mm, and I suspect the 124 is the same.

"Incurable" wheel balance problems are usually caused by tire out of round or radial force variation. When it's spinning on the balance machine I always view across the top to the tread to get a feel for runout, and it should be less than about 1 mm.

My suggestion is to find a shop that has a Hunter 9700 that can test the tires for runout/radial force variation. If they are out of spec you should be able to get an "adjustment" from the tire manufacaturer if they still have one-half of the usable tread left, but this varies with manufacturer.

I think you can find a local tire dealer with a 9700 from the following web site.

www.gsp9700.com

Duke

Re: front end shake @ 55-65 mph
 

Duke is right! Often the procedure is to seat the races by torquing to about 12 lb-ft while spinning, then with the wheel stopped, loosen and set finger-tight. Resulting adjustment should leave a small end-play. Else the bearings will heat up quickly and bind, then destroy themselves.

Steve

To check ball joints the front of the car should be resting on jack stands. Then use a floor jack under the end of the control until the vehicle just starts to lift off the floor jack. Then use a pry bar between the ground and the bottom of the tire and see if you get any movement at the ball joint.

Vibrations are caused by thing rotating, and looseness in parts will transmit vibrations. Even if the tire is "perfectly" balanced road feel can be transmitted thru the front suspension and if there is looseness you'll feel it.

Wheel bearings are set to 0.01-0.02 mm play. There are a few hueristics that can be used to get there. One is that the washer behind the lock screw should be somewhat stiff, but should turn with a screwdriver. Rocking the wheel at 12 and 6 and there should be a very small amount of play.

I'd check you front end again, make sure the wheel bearings aren't too tight. Rotate the tires to see if you can isolate the problem.

I'll throw my 2 cents and 30 years MB experience in with Larry Bible on this one. I've seen many internal tire problems that can only be verified by a tire swap. Many times old tires look new but are separating inside due to age. Look at the production date on the side of the tires.

Let us know who was right when you solve the problem. There is a lot of testosterone riding on this one.:D

Peter

First:Shake like that could be caused by wheels being out of ballance. I believe it's important that it be done on a computerized system IE: Hunter Balancer. Second: the suspension (tie rods etc) need to be inspected. Third: Bad wheel aligntment can cause different types of weird tire wear that can cause vibration in the steering wheel.

Abnormal wear in the tires can vary. I had vibration in the steering wheel on another car and went through the whole process. As it turns out the wheels were out of alignment and caused wear that was not visually obvious. I can't remember the term but each tread block was worn slightly uneven from front to back. The only way you could notice it was by running your hand lightly across the top of the tire from front to back. You could feel an edge at the begining of each block. Conversely a correct tire would feel smooth. You could feel it but you couldn't see it.

A wheel alignment and moving the tires to the rear solved my problem but not untill I spent $$$ doing everything else. The people ballancing my tires didn't even think of this.

As far as special stuff to check on MB ????

Stubman, I think the term is "feathering".

Actually I was told something else, because feathering is associated with outside to inside uneven wear and is usually visually appearent. This was from front to back on each block.

Who knows you may be right??