I am in the process of replacing the serpentine belt, shock and tensioner on my '86 300E. I have the belt off and I'm trying to get to the tensioner. Instructions for this procedure call for removal of the power steering pump. Several bolts are easy to get to but I think there are 2 in front of the pump that need to be removed also. My problem is getting these off(only one knuckle damaged so far).

My question is, do I need to remove the pulley for the pump in order to move it out of the way? If so what is the best way to do this?

Thanks in advance,

Blake
'86 300E (224K)

You don't need to remove the steering pump. You need to remove the pulley but, not the pump. I did mine a while back using the MB manuals. No problems. Where are you getting your instructions? I think there is a discussion in one of the forums. Do search. If you cannot find it, let me know...

Things have gone from bad to worse. I decided to tackle the tensioner another day and just put the new belt on. With new belt on, the hollow tension adjuster nut will not apply tension to the tensioner assembly. This makes no sense to me because I backed it off before I removed the old belt. The large 19mm bolt is loose during this procedure. I can't tell for sure but the tension adjuster threads may be stripped. Is this possible?

Blake

The threads are probably stripped on the adjusting tube. Mine stripped on my 103 engine. For a temporary fix I loosened the tube and wedged in a small u-bolt as a spacer so it would tighten up where the threads were good. The u-bolt I am describing was the type used to secure the cable system on garage doors. I had to grind it with a Dremel to get it to fit. It is still there. I bought the new parts but haven't installed them yet.

JDUB was most likely right. The rod that goes inside the tensioner will snap if you try to tighten the tensioner too much. I've been through two myself. They aren't very durable. The part is inexpensive. I've decided to let a Mercedes mechanic tighten the belt from now on.

You may be attacking the wrong part of the problem. With the 19mm retainer bolt loose and you cannot get the adjuster to increase the tension, you may have either broken the adjuster off of the collar at the rear of the tensioner or...the rubber insert inside the tensioner body has torn loose. First is easy to fix about $25 for adjuster and new collar, second will require a new tensioner body About $115 or so. Good luck..