| I feel a small vibration
when my car first shifts into second gear. It is more
pronounced when I have people in the back. What can
this be? |
| Your
Mercedes is equipped with a two-piece drive shaft.
Between the two shafts there is a universal joint.
Because of the length of the drive shaft, the u-joint
was installed there to prevent any large angles at
the front and rear, where it connects to the output
flange of the transmission, and the input flange of
the differential. Without getting to technical, it
is a good thing to have this type of drive shaft cause
it keeps objectionable vibration to a minimum. The
u-joint is the one component that is mostly overlooked.
A worn universal joint can cause vibration. |
| The
bad news is that the universal joint is
permanently installed in your original drive
shaft and was not intended to be serviced by
the do it yourselfer. Also it is very difficult
to find the proper universal joint since it
is not sold separately anymore. |
|
| The
good news is many cities have drive shaft
repair shops that can rebuild yours. They replace
the u-joint, and rebalance the shaft, for a
fraction of the cost of a new one. Usually this
service runs around $150.00. If you live in
a rural area, and don't have any service like
this, check the classifieds in "The Star"
magazine. It is publication geared to Mercedes
Benz owners. The other option is you may purchase
fully rebuilt units but at a much higher price.
|
| Also
inspect the flex disks. These can cause
vibrations also. They connect your drive shaft
to the back of the transmission and the front
of the differential. They are large rubber disks.
Look for any splitting, or reinforcement fibers
sticking out. If you find any of these conditions
replace them right away. The front ones should
last about 75K miles and the backs to last at
least 150K miles. First symptom is clunking
sound while coasting to a stop. |
| |
| Be
sure to check the center bearing supports
as well. These can wear out causing droning
vibrations at cruising speeds. |
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