Parts Catalog Accessories Catalog Tech Info Tech Forums
  Search our site:    
 Cart  | Project List | Order Status | Help    

Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Tech Help

Closed Thread
LinkBack Thread Tools Display Modes
Old 04-11-1999, 09:51 AM
Gabriel Ojeda
Posts: n/a
I am unable to tighten the belt on my 86 300E. I am not sure if the tension rod/nut have stripped or the belt tensioner itself is bad. (I am following the right procedure of loosening the 19mm bolt that holds the tensioner and then turning the tensioner nut clockwise. After sevral tuns of the nut it becomes very loose, making me think it is stripped or it has reached the bottom).

What is the procedure for removing the belt tensioner and the tension rod?

Is it true that MB has upgraded the tensioner for this car?

How do you test the shock absorber?

Thanks for the help.


Old 04-11-1999, 02:41 PM
MB Medic
Posts: n/a
I would suggest you start off by looking, with a flashlight, down the barrel of the adjuster nut. If the bolt is at the very bottom of the barrel nut then the tensioner's rubber bonding has seperated. the rubber bonding is what the tensioner uses for a spring, so long as the rubber stays attached to both inner and outer housings. Also remember that the threads of the bolt and nut are left handed.
To remove the tensioner:
1)Remove fan blade assembly and fan shroud.
2)Break loose the 3 bolts attaching the water pump pulley and the power steering pump pulley and the 4 bolts for the fan pulley then take the belt off.Then take the pulleys off.
3)Take loose the belt tensioner shock at the bottom mounting point on the tensioner( some have a nut on the back so look first )
4)you will see the 19mm bolt head for the tensioner goes thru a "Y" shaped bracket. There is an 8mm bolt(13mm head) at each points of the bracket.The one to your left at the fan pulley bracket is a special shouldered bolt. The bottom of the two bolts to your right in th power steering pump has a nut on the back of it. Then take the 19mm bolt out of the center of the tensioner and work the tensioner assembly out.
Pay attenion to the way the adjuster bolt is postioned on the rear of the tensioner for re-assembly.
5)re-assemble in reverse order. you will find a white plastic pointer between the tensioner and the bracket, put it on the new tensioner assembly to the right hand side of the marks(as it tensions the pointer will move to the left).
As for the tensioner shock check the bushings at both ends to see if they are loose in the housing. Try to compress/extend the shock you should feel resistance both ways.
If you don't feel confident in your ability to do this job( if it's needed ) then seek out a reputable MB shop to do the work for you.

MB Medic
14 year MB tech
7 year shop foreman @ independent MB/Volvo shop
Closed Thread


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
350SDL belt tensioner common prob, redesign? DonBaker Diesel Discussion 5 05-03-2004 08:51 AM
M112 Belt Tensioner ricerokets4life Tech Help 4 01-18-2004 09:49 PM
603 belt tensioner sixto Diesel Discussion 8 12-21-2003 10:35 PM
Hello everyone..I'm a newbie, with a belt tensioner question???? jay3000 Tech Help 2 12-20-2002 05:04 PM
300E belt tensioner problems anthonyb Tech Help 16 10-08-2001 09:15 PM

All times are GMT -4. The time now is 06:32 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page