Serpentine Belt
 

I need to replace the crank pulley on my 2001 3200 SLK (112 engine)

Does anybody know whether the bolt which secures the crank pulley is conventional or left handed thread?
What torque should it be tightened to please.

Stuart

RE: Serpentine Belt
 

stuart, your SLK3200 must have lots of power.

the bolt is normal thread direction.

tightened it to 200Nm plus 90 degrees torque angle.

RE: Serpentine Belt
 

Thanks Sleepwalker

I actually found the 200Nm + 90deg but couldn't quite believe it. That's mega tight. No wonder I can't undo it.

At least I now know I am trying to undo it in the correct direction!

I've made a counter rotation tool to hold the crank pulley since the torque (to undo the bolt) is sufficient to damage the torque converter mounting plate, if the usual starter ring gear locking device is used.

Better get a bigger bit of scaffold pole!!

The crank pulley /vibration damper is falling apart. Aparently this is quite a common problem. At least a replacement damper wasn't terribly expensive.

Stuart.

RE: Serpentine Belt
 

200nm isn't much since the wheel bolt is already 150nm and we really don't feel it hard to unscrew. however, the 90 degrees crank angle is annoying because of lack of space.

don't hold the pulley from outside since there's a rubber sandwiched between it. only on the inner part.

RE: Serpentine Belt
 

Hi,

200Nm isn't much? Its quite tight but a further 90deg takes it up to? I needed a 6ft pole to apply sufficient torque.
Made my own device for holding the pulley on the inside (tube with 6 fingers) and reacted it against the subframe. Worked a treat.
Bolt also had Locktite on it.

RE: Serpentine Belt
 

:D 2 feet is good enough.

nice fabricated tool you got! am using 3 fingers made by mb.

RE: Serpentine Belt
 

Did you check with your dealer to see if the car was under the HB campaign?

RE: Serpentine Belt
 

My breakback torque wrench is easily two feet long. My wrench goes up to 250Nm. You must be a lot stronger than I!
I admit it was easier tightening the replacement pulley bolt than undoing the old one which was the real problem.
Anyway SUCCESS.
I now understand why they tell you not to lock the crank at the ring gear.

RE: Serpentine Belt
 

Hi Bryan,

Are you in the States, UK or where please?
I was unaware of any HB campaign. Got any more details please?
MBUK operate under entirely different criteria to USA. Unless the car is within the strict 3 year warranty they don't want to know particularly when a part has been changed under warranty and failed again. e.g. Catalyst rattle.

Stuart

Pulley Recall
 

http://www.benzworld.org/forums/foru...233163&posts=2

http://www.mercedesshop.com/shopforu....php3?t=119790

Bazzle