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  #1  
Old 12-04-2007, 03:38 PM
AUBluTiger
 
Join Date: Jul 2007
Posts: 70
Timing Chain on 450SL

Just curious...saw the previous thread about timing chains and starting to wonder about mine...I have a 76 450SL. It has about 144,000 on it....is it one of the ones with the single row that needs to be converted to a dual row, or had MB already addressed it at this point?
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2006 Audi A4 "Audrey"-daily driver
1976 MB 450SL "Marlene"
2000 Jetta VR6 "Julia"-traded at 220k miles
1997 Jetta 2.0Trek "Blanche"-traded at 450k miles YES 450,000 miles
1986 Prelude "Gladys"-died at 120K miles
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  #2  
Old 12-04-2007, 03:45 PM
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you should be fine
For model year 1981, Mercedes substituted a lighter, more efficient all-alloy 3.8 liter V-8 for the old reliable iron-block 4.5-liter V-8. And along with it came trouble.
The engine has a single-row timing chain, which as the miles piles on, tend to stretch. Unchecked, the chain can jump its sprockets, causing pistons to collide with valves, leaving the 380SL owner facing a $6,000 repair bill. During 1984, Mercedes switched to a double-row chain and solved the problem
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Ron
2011 Porsche Cayman - Bond,James Bond
99 E320 THE Queen Mary
62 220b - Dolly - Finally my Finny!
72 450SL, Pearl-SOLD
16 F350 6.7 Diesel -THOR
07 Lexus RX 350 - Lexi
14 38HP John Deere 3038E Tractor -Mean Green
84 300SD, Benjamin -SOLD
71 220 - W115-Libby ( my first love) -SOLD
73 280 - W114 "Organspende" Rest in Peace
81 380 SL - Rest in Peace
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  #3  
Old 12-04-2007, 03:52 PM
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Location: Seattle WA
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the 76 450sl has the double chain. usually the chains only need to be changed when they stretch (which you can check on the timing marks on the crank).
if you have never changes the top chain rails however you are living on borrowed time. Thats what happened to the last one I rebuilt, the rails are plastic and get brittle and break at the holding pin. The engine in the picture I poted earlier broke off and jammed in the cam and caused the chain to jump one tooth. the exhaust valves hit the pistons on the drivers side bank. its both time and mileage that contribute to the guide rails breaking, if your car has done less miles but the guides are still 20 years old you still have a problem, they just get brittle. of course some of you may be lucky and have the metal guides then you dont have to worry but I think they stopped using those in 74 sometime.

the plastic guide rails cost 5 or 6 bucks each from the dealer (dont be tempted by cheap looking after market ones just buy them from the dealer) there are 2 on the drivers side and 1 on the passenger side, you can change the tensioner rail cover but Ive not seen one break up and its a PITA to do.

I posted a pic of a home made rail pin puller that I welded up, if you want a copy I can email it to you.
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61 Austin mini
67 Lotus 7
74 450sl
76 Cadillac 8.2l (501 ci)

some new cars

megasquirt conversion on:
djet 74 450sl http://www.mercdjetmegasquirt.britautorepair.com/
cis 76 450sl http://www.merccismegasquirt.britautorepair.com/

the best view is always from the point of no return
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  #4  
Old 12-04-2007, 03:55 PM
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Quote:
Originally Posted by Gurunutkins View Post
. usually the chains only need to be changed when they stretch (which you can check on the timing marks on the crank).
can you post details of this procedure?
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Ron
2011 Porsche Cayman - Bond,James Bond
99 E320 THE Queen Mary
62 220b - Dolly - Finally my Finny!
72 450SL, Pearl-SOLD
16 F350 6.7 Diesel -THOR
07 Lexus RX 350 - Lexi
14 38HP John Deere 3038E Tractor -Mean Green
84 300SD, Benjamin -SOLD
71 220 - W115-Libby ( my first love) -SOLD
73 280 - W114 "Organspende" Rest in Peace
81 380 SL - Rest in Peace
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  #5  
Old 12-04-2007, 05:58 PM
Gurunutkins's Avatar
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Join Date: Oct 2005
Location: Seattle WA
Posts: 496
here is the link to a superb article by our own tomguy

tells you everything you need to know

http://www.peachparts.com/Wikka/M117TimingChain
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61 Austin mini
67 Lotus 7
74 450sl
76 Cadillac 8.2l (501 ci)

some new cars

megasquirt conversion on:
djet 74 450sl http://www.mercdjetmegasquirt.britautorepair.com/
cis 76 450sl http://www.merccismegasquirt.britautorepair.com/

the best view is always from the point of no return
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  #6  
Old 08-06-2013, 04:00 PM
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Chain worries

For some reason i started to read tales of woe about timing chains.. N now it has me worried.

I have a 1973 450sl . European with 135k miles or so and no service history ... Last couple of years Ive had timing and injector issue and now planning to go pertronix.

Was reading this thread and hoping i dont have any worries ... Am i correct to assume The older engines dont have timing chain or guide issues
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  #7  
Old 08-06-2013, 07:59 PM
meltedpanda's Avatar
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Sorry but that is not the case, pull the cover , check your stretch , then we can better inform you on the next steps.
All of these cars, double or single chain have chain/tensioner wear, it is a maintenance item just like all other high mileage needs
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Ron
2011 Porsche Cayman - Bond,James Bond
99 E320 THE Queen Mary
62 220b - Dolly - Finally my Finny!
72 450SL, Pearl-SOLD
16 F350 6.7 Diesel -THOR
07 Lexus RX 350 - Lexi
14 38HP John Deere 3038E Tractor -Mean Green
84 300SD, Benjamin -SOLD
71 220 - W115-Libby ( my first love) -SOLD
73 280 - W114 "Organspende" Rest in Peace
81 380 SL - Rest in Peace
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  #8  
Old 08-07-2013, 02:54 PM
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Thanks for the quick response ... Not what i was hoping for ... Now have a project for the winter.

Ive see the steps from the link in the previous thread for measuring stretch but what about the tensioner wear. Is that if the chain is stretched the whole lot needs changing
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  #9  
Old 08-07-2013, 03:31 PM
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Tensioner is the major problem on the '73. It weakens over time. It is external and fairly simple to replace. If original the guides are metal backed and while the do wear they don't break like the plastic ones. Chain stretch is a combination of chain stretching and sprocket wear. Cam sprockets wear the most.
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  #10  
Old 08-07-2013, 03:46 PM
meltedpanda's Avatar
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I knew he would show up ( Rowdie that is ) I Would add , that if the chain needs replaced I would do the tensioners as well
by measuring your stretch you may be able to tell if just a tensioner will help ( rare) or if you need to do the whole deal.
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Ron
2011 Porsche Cayman - Bond,James Bond
99 E320 THE Queen Mary
62 220b - Dolly - Finally my Finny!
72 450SL, Pearl-SOLD
16 F350 6.7 Diesel -THOR
07 Lexus RX 350 - Lexi
14 38HP John Deere 3038E Tractor -Mean Green
84 300SD, Benjamin -SOLD
71 220 - W115-Libby ( my first love) -SOLD
73 280 - W114 "Organspende" Rest in Peace
81 380 SL - Rest in Peace
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  #11  
Old 08-07-2013, 05:16 PM
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Thanks gents Great service. Now I need to do some research
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  #12  
Old 08-07-2013, 07:05 PM
meltedpanda's Avatar
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let us know how it ends up!
Just met a young man from Ireland, County Cork (sp) I beleive. Nice young man , he is an exchange student
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Ron
2011 Porsche Cayman - Bond,James Bond
99 E320 THE Queen Mary
62 220b - Dolly - Finally my Finny!
72 450SL, Pearl-SOLD
16 F350 6.7 Diesel -THOR
07 Lexus RX 350 - Lexi
14 38HP John Deere 3038E Tractor -Mean Green
84 300SD, Benjamin -SOLD
71 220 - W115-Libby ( my first love) -SOLD
73 280 - W114 "Organspende" Rest in Peace
81 380 SL - Rest in Peace
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  #13  
Old 08-07-2013, 09:17 PM
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Location: NE Oklahoma
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Section 05 here has information worth a read. Section 07.4 is a good reference for your D-Jet injection. The Encyclopaedia Germanica Volume 107 (aka EGv107) - Benzworld.org - Mercedes-Benz Discussion Forum

Many members here are also members there.
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  #14  
Old 11-08-2013, 03:11 PM
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Join Date: Aug 2012
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seems I'm in the manure

looking for anything I might have missed or got wrong - so I don't have to replace the chain. 1973 450SL with 136k miles.

I have followed the instructions for checking for the stretch in the chain and I seem to have about 15deg stretch - and before I start ordering parts a couple of questions to set me straight. - There is a split pin on the chain so can I assume it was changed before - all seems good and tensioned. ?
(photos attached)

1. 15 deg's is too much - most of the posts I see say 5 to 8 is max

2. how do I judge if I need to change the sprockets

3. the local merc specialist says it 20 years since he has done one and not keen to do mine. (poss also expensive)

3. is it a job for a reasonably handy mechanical minded hero - with no experience of this job.

any advice greatly appreciated
Attached Thumbnails
Timing Chain on 450SL-2013-11-08-15.48.43.jpg   Timing Chain on 450SL-2013-11-08-15.49.02.jpg  
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  #15  
Old 11-09-2013, 05:35 PM
meltedpanda's Avatar
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yes 15 degrees is too much
but at 136K it would seem to me that needing another replacement makes me think that perhaps the last one was done incorrectly
Sprokets rarely wear , but the tensioners should be done
You could do it , it is tedious and exacting. many good threads about it here on this forum and other
An indy would probably charge 1500, an MB dealer -3 K
At 15 degrees of stretch are you having trouble setting timing?
Do you hear chain slap at start up?

there is an outside chance it is a broken or severly worn tensioner , chain may be OK
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Ron
2011 Porsche Cayman - Bond,James Bond
99 E320 THE Queen Mary
62 220b - Dolly - Finally my Finny!
72 450SL, Pearl-SOLD
16 F350 6.7 Diesel -THOR
07 Lexus RX 350 - Lexi
14 38HP John Deere 3038E Tractor -Mean Green
84 300SD, Benjamin -SOLD
71 220 - W115-Libby ( my first love) -SOLD
73 280 - W114 "Organspende" Rest in Peace
81 380 SL - Rest in Peace
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