I am original owner, it has 149K miles on it and has been one fine car.

There is a noise in or on the front of the motor that sounds like a moderate hammering noise. It is most noticeable at idle and goes away as speed increases.

I just finished driving 400 miles pulling a closed motorcycle trailer often at 80-85+ MPH and the noise has not gotten worse. The noise almost disappeared completely at highway rest stops after high speed runs. The noise is back while driving around town now.

I seem to recall that replacing the shock and tensioner assembly on the serpentine belt pulley in the past may have eliminated a similar noise, am I right? How can you tell if the belt tensioner and/or shock need to be replaced? I also seem to recall that certain spring and shock assemblies were better than others, is this true? The shock on there now looks like it has non MB markings on it.

Can the shock be replaced without removing the fan hub? If the hub has to be removed is it an easy job?


Thank you.

ezrider,

Just had mine done less than a month ago. The difference was night and day!

The bushing in the shock is the thing that apparently goes.

My mechanic took a huge screwdriver and stuck in in between the shock and front of the engine and as he put tension on it the "hammering" stopped.

__________________
Frank
84 500SEL EURO 101K ( JUST LIKE MY 1ST WIFE. GLAD TO GET RID OF HER! )
85 300D 310K (sold)
90 350SDL 184K sold
83 300D 118K (sold)
88 300E 153k (sold)
93 400E 105K (sold)

The "hammeriing" ususally comes from the bottom of the shock's bushing. Wears out big time and gets worse with time. At above idel noise goes away.

Just replaced my this morning. Almost a no brainer on my 86 SDL. Major difference in noise level. Can finally hear the engine again.

Remove bolt and metal clip from top of shock. Slide shock to the left.
Remove nut and slid back bolt from top of tensioner spring.
Lift out tensioner spring. Hooks to the right side of the tensioner.
Tensioner will now piviot up on the left side to just allow the bottom bolt of shock to by-pass the fan pully. No need to pull fan pully.
Remove old shock and replace with new shock.
Reverse to re-install.

Check belt and make sure its riding on all pullys. check all bolts. Double check everything again.

__________________
1986 SDL
My Other Car is a Porsche. When it stops leaking, I'm out of oil.

Hi Alan,

Do you need any special tools to do this? Do you think the procedure is the same on a 350 SDL?

Thank you.

No special tools. Just 10-11-13 MM wrenches if it's just the "shock". Don't know if it the same on the 350 but it should be. Performs the same function....NOTHING....

Just follow proceedure on this post.

Make sure it's the shock and buy one first. $20 I think.

__________________
1986 SDL
My Other Car is a Porsche. When it stops leaking, I'm out of oil.

I also had a wierd noise ....and it turned out to be my fan clutch that was going out



Warren
1992 300SD 164K
Columbus Ohio