Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help

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

LinkBack Thread Tools Display Modes
Old 07-26-2002, 04:56 PM
Posts: n/a
450SL Timing chain Stretch

I just adjusted my valves on my 1973 450 SL. The car has 183000 miles on her. I noticed the timing chain seems a little loose at certain spots on the rotation during the valve setting. There are spots where I can pull the chain away from the upper rails and touch the head casting. I have read some threads that say the Chain Tensioner is supplied oil to create pressure on the chain. Is this correct?? If that is true, then can someone tell me how to check chain stretch on the car using the crankshaft pulley? The guides I can see with the valve covers off, all seem ok. I am wondering if the chain tensioner is not functioning correctly. Previous original owner says she had "valve work " done some years ago around 145000 miles, but can't recall just what was done.

Reply With Quote
Old 07-26-2002, 08:51 PM
Registered User
Join Date: Aug 2001
Location: Evansville, Indiana
Posts: 8,150
To check chain stretch, rotate engine until the right camshaft alignment mark and the mark on the cam tower are matched up -- nominally TDC on the crank. Look down and see how many degrees the crank is after top dead center -- this is the chain stretch (wear) in degrees. Less than 8 degrees is fine, more, replace the chain.

If the chain is sloppy, the tensioner is leaking down and should be replaced or repaired -- the internal o-rings are shot. Not too hard to do, it is under the alternator below the head on the front cover. I'd fix it, a slapping chain can break the upper guide, and that usually gets in the chain and breaks that, bends the valves on both heads and costs $$$$$.

1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!
Reply With Quote


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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 02:29 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page