85500sel

Hi, I aquired an 85 500 SEL w/117xxx miles yesterday. I have lurked here and in some other forums and it looks like the timing chains on these cars are replaced often. Is there a standard to measure the wear of the guides? I read a post on measurement of the chain but how do you tell if the guides are worn? Is this something I should just automatically change on a 20 year old car w/ 117K miles? Are there any other items that I should look into?

The 14" wheels and tires look a little too 'weak'. Are the 16" wheels (I'll figure the tire sizes to adjust gearing) from newer MBs the same offset and bolt pattern?

Thanks,
Don

Hattaresguy

The chains on the V8's are very long, the plastic guides tend to crack and brake on start up. Some very good MB mechanics have told me that the chains should be done every 10 years or 100k miles. However the M116 is more prone to chain failure then the M117. I still wouldn't take an M117 much past 130k.

Personaly if it were my car I would do the chain soon.

16in, 8 hole wheels are a nice upgrade. If they are off an SL (R129) they will not fit, but I think W140 wheels with different tires will.

dtkw

I didn't want to take a chance so I changed mine before it reached 100K. Just to make me sleep easier without the thought of the chain breaking on me and cause more damage.

golfboy

I didn't know that this was a problem with our cars... and my mechanic didn't tell me. Mine broke at 120k - $3000 repair bill to put on new heads.
My advice - replace the chain and guides.

85500sel

How do you relieve the pressure in the chain tensioner? I was told that the removal of the guides would be self explanatory once I saw them...I guess I am short a few points on the IQ meter...how do the tensioner holding pins come out?


The MB CD manual SUCKS. It doesn't even cover the timing chain and guides! Any other source?

Don

MBHustla858

you'll know when the chain is slappin around. ur gonna hear it. somewhat of a claking noise. and its really not that difficult to do, normally i just connect the new chain to the old one and roll it in.

m117968

Well, there is a bit more to it then 'just rolling the chain in'. I use 3 sets of vice grips on the timing gear to ensure the chain does not skip teeth as the whole assembly likes to jump forward at least a few times during instalation. To gain accress to the guide rails you will need to remove the alt. and it's housing as well asn the power steering pump/bracket.

It's a job you should go about gingerly the first time through as mistakes can be costly in both time and money.

Jonathan
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85500sel

Thanks for the responses.

Update...I have managed to change the guides and timing chain. This would be an easy job on a new car but on one whose bolts have not been removed in 21 years was a pain. I wonder why MB used allen heads on the alt. side and hex heads on the PS side. One of the alt. bracket allens rounded off. I ground down a larger allen wrench and stuck it into the rounded off bolt w/ some jb weld and left it there for a day....did the trick. Removing the guide pins was a nightmare. The bolt and washer method worked for all but one. The bolt broke off in the pin. The easy out broke off in the pin. Luckily it was the uppermost pin on the driver's side so I cut the guide off, cut the pin and tapped it out from the inside.

The only thing I have gained w/ the chain and guide replacement is peace of mind as the chain only had 2* of stretch and the guides were not brittle. I bent the old ones and they darn near folded in half before they broke.

Why isn't there a guide made like the tensioner guide...w/ metal backing?