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Premium Member
1987 560SL
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2,338 Posts
Discussion Starter #1
MERCEDES BENZ TIMING CHAIN & GUIDE RAIL & TENSIONER REPLACEMENT - YouTube
I installed a new MB timing chain, upper guide rails, chain tensioner, sprockets on my 450SL at 102,000 miles. I videotaped the whole procedure and although it was a neophyte attempt, the car started on first try. I put a 30 minute video summary for those who are considering doing it yourself, or welcome comments from those who have boldly gone where no man has gone before. The MB mechanic's estimate for this job was $1,700. My total cost was about $300 plus personal labor and selfie-video editing time. The job requires typical mechanical skill, good metric tools and patience, but the outcome is priceless!

 

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1983 380SL, ivory/dk brown, 46k miles, dual roller timing chain. 1986 560SL, red/white, 190K mile.
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6,738 Posts
Very informative video. Never replaced a Timing Chain before. Have replaced a
Timing Belt.

Did not understand the need for two Zip Ties - could just one have worked as well?
Also, it looks like the old chain is not under tension as it exits the engine.
Looks like it could have jumped a tooth or more ????
 

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Premium Member
1987 560SL
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2,338 Posts
Discussion Starter #4
Very informative video. Never replaced a Timing Chain before. Have replaced a Timing Belt. Did not understand the need for two Zip Ties - could just one have worked as well?
Also, it looks like the old chain is not under tension as it exits the engine.
Looks like it could have jumped a tooth or more ????
Thanks the video is meant to inform, I had the benefit of all the written information here so the movie builds on the collective wisdom.

Using only one zip tie will allow the chain to jump when you move the tie to the next sprocket hole. Definitely need two; several of the timing chain threads on this forum recommend three, but that could be cumbersome.

Correct, the old chain is not under tension as it exits the engine. Not sure why you say it could have jumped a tooth, that I do not understand.
 

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Registered
1983 380SL, ivory/dk brown, 46k miles, dual roller timing chain. 1986 560SL, red/white, 190K mile.
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6,738 Posts
Thanks the video is meant to inform, I had the benefit of all the written information here so the movie builds on the collective wisdom.

Using only one zip tie will allow the chain to jump when you move the tie to the next sprocket hole. Definitely need two; several of the timing chain threads on this forum recommend three, but that could be cumbersome.

Correct, the old chain is not under tension as it exits the engine. Not sure why you say it could have jumped a tooth, that I do not understand.

You definitely have expanded knowledge with your video and given
many of us the courage to try it ourselves. OK, now I understand the
reason for 2 zip ties.

As the old chain exits the "abyss", I think I understand now. Are you
using a spacer to push on the Rail to hold the exiting Timing Chain against the Sprocket
as it comes out of the Engine Block ???

Carl
 

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Registered
1983 380SL, ivory/dk brown, 46k miles, dual roller timing chain. 1986 560SL, red/white, 190K mile.
Joined
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6,738 Posts
I think we need to get a cute little honey in a short dress to show us
how to renew the Timing Chain. I would oogle and later feel my male ego
crushed and be forced into attempting a Timing Chain renew. I know,
I'm a dirty old man:)
 

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Premium Member
1987 560SL
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2,338 Posts
Discussion Starter #10
As the old chain exits the "abyss", I think I understand now. Are you using a spacer to push on the Rail to hold the exiting Timing Chain against the Sprocket as it comes out of the Engine Block ??? Carl
Carl, the exiting chain falls on its own weight, just gravity. There was no need to push on the rail to hold it; the clockwise rotation pulls against the two cams that are spring loaded so there is plenty of tension to hold the chain, the only point where the chain could jump is where the cable ties are fastened.

Fantastic information. Thank you very much. I'm curious how much clock time it actually took you to do the full job?
My clock time is not accurate because I spent a lot of time running a video camera; because I had all the parts except a second set of plastic oilers that I had to order and wait for it; the video shows I got distracted by polishing the aluminum parts and using up some leftover paint (so there was dry time); there was beer involved (so there was wet time); and finally my new four post lift arrived smack in the middle of this job so I had to raise a few vehicles just for grins. So maybe others who did the job can give a better estimate; I WAG it was 8 hours; the raw video time was about 3 hours edited down to 30 minutes, but I really dunno...

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Neither a bloody knuckle seen nor a curse word uttered. The man's a farging machine...
That stuff got edited out but there is a WTF at 18:16, thanks for the PG rating.
 

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Registered
1983 380SL, ivory/dk brown, 46k miles, dual roller timing chain. 1986 560SL, red/white, 190K mile.
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6,738 Posts
Would you recommend this task to someone who has never changed
out a timing chain before?
 

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1976 450 SL
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71 Posts
I'm at 130k+ and will need to tackle it eventually. This answered a few noobie questions for me in the way I learn best. I really like the fact you pointed out the things a noobie might not think of and would woefully regret not doing(cardboard on the radiator, under the chain and the magnetic pan). Thanks for sharing.
 

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Premium Member
1987 560SL
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2,338 Posts
Discussion Starter #14
Would you recommend this task to someone who has never changed out a timing chain before?
Yes, I never changed the chain before, just followed the written instructions on this BenzWorld forum; lots of good advice here. Anyone doing this needs some mechanical skills, a well lit garage, and a good set of metric tools. Also don't go into a house with white rugs and helpful to have a dark colored dog for the occasional affectionate hand wipe.
 

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Outstanding Contributor , Bob's Your Uncle!
-----'83 280 SL----- 5 speed....The PIG
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1976 450sl
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71 Posts
Is the zip tie solution still advisable if the cam followers have been removed? I am already in the midst of a valve seal replacement and could leave out the cam followers if it made things easier/less stressful for this project which is next in line. Thanks for your time.
 

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86 560SL
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1,243 Posts
I tackled the guide rail job a couple weeks ago. Glad this video was available. I watched it a couple times.
I decided against changing the chain because my total stretch was about 2.5 degrees on the harmonic balancer once I had the timing marks on the camshafts lined up. The engine has only 47k miles on it but is 30 years old that's why I only did the guides.

I did run into a major issue. As @PanzerPuff indicated in the video, mark the sprocket and chain so during reassembly you can align them again and the camshaft timing will be correct. By the time I had the first sprocket off my marking on the sprocket was worn off (left cylinder bank). Before I moved forward I guessed at the alignment, slid the sprocket back on the camshaft and slowly turned the engine over by hand a few times. I got lucky and I had perfect alignment of all the timing marks.

After reassembly, time came to start the engine. I took the fuel relay out and cranked the engine over a few times with the starter, figuring if I messed up it might bent a few valves but won't destroy the whole engine. All was well. Plugged the relay back in, engine started right up and after a couple seconds died.
The 560SL engine has an engine temperature sensor mounted to the back of the engine and close to the left valve cover. To get the valve cover off more easily I disconnected that sensor. Plugged the sensor in and the engine runs perfectly.

So for a little fun afterwards I tested the old guides to see how brittle they were
 

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