last year I drove my 81 300SD at 160 km/h and it was as smooth as silk. Last week I had a chance to speed again and the car started shaking noticably at around 140. Except for replacing my rear pads I haven't touched the driveline since. Any ideas as to why she shakes?

Thanks in advance.

May be your tires need to be balanced and rotated. Or possible weak motor mounts.

Your problem is most likely tires, but without driving it myself, it's difficult to know.

I have had a number of problems over the years getting the tire people to balance the tires properly. First of all, the balancing machine MUST be set up to add weight to the inside AND outside of the wheel if needed. It is very common for them to put weights on the inside only. Their response is always "most people don't want those ugly weights on the outside of their alloy wheels". Insist on balancing inside AND outside. A good alternative is using tape weights on the inside diameter of the rim as close to the outside of the wheel as possible. This is the ideal way because of the third problem, alot of the weights the tire stores use won't stay on a Benz wheel. This leads to what very likely is wrong with your car, one or more weights may have come off.

Good luck,

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Larry Bible
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

Lube:

How long had the car been sitting? If it was for a few days, there may have been flat spots on your tires. I drive my car maybe once per week. When I get onto the freeway I'll notice vibration like my tires need balancing, but I know it's the flat spots. Once the tire temp increases the vibration goes away. Might this be what's happening with your car?

Just a thought.

Brian

I took it to a shop that specializes in Euro cars. They said that I need new idler, centre link and tie rods. Is this a common problem on old 126s? Are these difficult to replace for a saturday mechanic?

Is there anyway I can check if these components are faulty. I plan to be under the car this saturday. If necessary I'll replace these parts myself but I want to be sure that they are the culprit. As per Larry's comment my tires are currently 3/32 in front and 1/32 in rear so I'm sure they're partly to blame.

Thanks in advance,
Lube 81-300SD

Lube

The tie rods, centre (drag) link, and idler arm are the steering components. The car must be aligned after you changed the tie rods. Changing all these will reduce the play on your steering wheel (assuming there is play right now) but it will probably not solve your shaking problem.

Your shaking problem is probably tire related. Since your tires are quite worn, it is probably time for new tires. When you install your new tires, have the shop check the wheels for trueness. Good luck.

Thanks Tommy,

I'm still wondering about the steering components though, is there anyway for me to check if they are faulty, (visually or by hand inspection)? My steering is remarkably straight and doesn't wable or wander. Tires are gonna get replaced though.

Thanks in advance.

Hello Lube:

I had a similar high speed vibration that appeared at 180 kph all the way through to 225 kph, which was cured with a dynamic wheel balance of the front wheels done at the dealer here in Edmonton.

They have the equipment to spin the wheels on the vehicle and balance them "dynamically" instead of the usual static, or wheels-off balance. This procedure also balances any vibration in the other rotational components attached to the wheels such as the brake disks.

The service manager said they had to get that equipment a few years ago when the S-class was having problems with faulty wheels, so I'd assume they would have it in Calgary too.

It worked wonders...now I need to improve the aerodynamics a bit 'cause she begins to float a little when driving above 220 kph!



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Dean Albrecht
94 E500
99 ML320

Your car is very forgiving about balance if you have stock 70series tires. Wheel vibration really gets tricky with wheel in the 16+ inch diameter.

Anyone with vibration problems with those wheels would best be served by finding a shop with the equiptment and techniques described here:
http://www.gsp9700.com/pub/technical/4426T/4426t.htm

I still believe that your "shaking" is tire related. If you want to check your steering components, raise the car in a safe manner. If you have nothing to work with except the MB jack that came with your car, it won't be safe enough. If you do have the equipment to do so, you should be able to raise both wheels off the ground. You then should be able to shake and pry on your steering components to check for any play.

I'm a bit skeptical about these all being worn. My 240D still has the original idler arm and centerlink. I've replaced the tie rod links only a few weeks ago. If these components are loose, fine, they need replacing, but I wouldn't expect them to cause the shake.

Good luck,

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Larry Bible
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

Thanks to everybody for their replies. i lifted me car this weekend and noticed that with the wheels hanging I couldn't budge the tie rods. But with the wheels on the ground they do have a bit of play. My guess is that driving around with loose tie rods has put excessive and unusual wear in my tires, hence the shake. I'll be replacing both soon (tires and tie-rods).

Thought I'd update:

I threw in a new set of tie rods, idler bushings,steering shock and had the front wheels balanced for the 2nd time in as many months (1st time the weight fell off).She's straight and solid now. I figure I'll wear the tires i have down until it becomes time to put on a set of winter tires.

Thanks to all for their feedback and assistance.

Also, the procedure Dean mentioned is called a "zero balance".