My '03 C240 tends to shake whenever I go faster than 70mph (so far it's kept me from getting speeding tickets..)...what could be causing this? Also, whenever I go over a bump on the road, my suspension squeaks like an old mattress..what do I need to change? How much will this cost me??

Thanks in advance!

 

Shaking at speed: These are the things I would check, and if you do not know how, or do not have the tools, you will need help.

1) Jack the car up until the wheels are off the ground.
Follow all safety instructions for using the jack.
Using your hand, spin eachwheel and tire.Spin it as fast as you can by hand. While it is spinning, watch to see if the wheel and tire seems to move up and down, or in and out. Any sign of wobble or "out-of roundness" couldindicate a bad tire or bent rim. To see if the wheels and tires are precise enough to "ride like a new Mercedes",a "dial indicator and stand" can be used to measure "wheel precision", damage, "run-out" etc. This will indicate if there is even the slightest wheel damage. The wheel and tire should spin true and round. Any damaged wheel or tire should be replaced.

2) If wheels and tires seem or measure to be round and in good condition, "wheel balance" may be the problem. Sometimes thelittle balancing weights will fall off on the road. Have someone check and re-balance your tires.

3) Its probably not your struts or linkage, unless the vehicle has been damaged in an accident,or has very high mileage,butextreme wear in the suspension can cause shaking and poor ride at the least.

Squeekingnoise: is hopefully just dirty or old bushings in the suspension. Try cleaning them and spraying them with some armor-all. If that doesn't work then you may very well have some badly worn bushings or struts.

Shaking when appying the brakes might indicate a warped rotor, but you said it always shakes.

Get it fixed soon. It will eventually make you angry at your car, and it is really notyour car's fault. Trying to keep aluminum rims and tires in good condition is tougher than ever. Definitly avoid those pot-holes in the road, and try to find a good tire store; some bad stores do very sloppy work, and do not balance the tire properly. Also there is a potential for off-priced/dicontinued tires to be out-of round when new, and might not give you the ride you expect.

good luck

Blue

 

Hi,
BlueSilver gives good advice but a few other points.Get this checked out, May well be worn ball joints (Steering or Suspension).
You do not mention mileage covered.
Worn bushes will make the whole wheel tyre assembly more susceptible to run out and poor balance.

If indeed the ball joints and tyre run out and balance are OK it is possible that the tyres suffer from something called poor RFV Radial ForceVariation.
This is like the run out that you have already checked for but can only be identified with the tyre loaded (i.e. car on ground or tyre running on a special drum which simulates the ground).
The key question here is when were the tyres changed. When did the problem start. Where did the tyres come from. What make etc are they.
Well known, MB recommended, premium brands are less likely to suffer RFV problems but any tyre can be outside limits and impact on vibration in this way.

A bit more vehicle history may well narrow the likely problem field for you.

There are of course other sources of vibration other than the wheels and tyres.

Stuart.

 

Thanks for the advice! I had my brother ride in the car and he mentioned I might just need new tires--I got the car with 60k miles on it and I'm up to 70k now..so maybe it's time! He also mentioned the bushings...I will try to "clean" them before I run out and get them replaced.

Thanks again!