Hi all,

Some may remember that I checked the timing of my 5.0 M117 engine and the right cam was off by 4° (ie the crankshaft pulley was 4° atdc when the right cam was on the mark).

I took advantage of having the engine out of the car to take out the timing cover to inspect the guiding and sliding rails as well as the gears, see pictures below.

There is some evidence that the timing cover has been taken out sometime before in the life of the car and that the rails have already been replaced. I would like to have some opinion on the following:

how worn are these rails? What does their color tell?

How worn are the gears? How do I measure their wear? Does it make sense to replace them together with the chain, knowing that I am on a tight budget?

What about the gear bushings? Are they replacement items? How do I measure their wear?

What about the oil pump chain rail?

I would like to do what is necessary for the engine to run smooth and be reliable for the next 100,000 miles, but as said above, I’m on a tight budget. So I need some help to strike the best compromise.

Thanks to all in advance!

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Some more pictures:

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Those rails were white when they were put in and have become discolored. They are cheap, so replace them. In addition to them, while you have the engine out, I'd replace the timing chain and tensioner. The camshaft sprockets don't appear to be that bad. Mine were worn to the point the tips were bent over at an angle--very close to a catastrophic failure.

There are plenty of directions on how to roll a chain in available here. If you don't have the right tool to take the retaining pins for the rails out, you can manufacture something by finding a bolt that will screw in to the pin or find a small puller to do that job. Only thing to worry about with the sprockets is which side goes toward the chain. Can't remember right off the top of my head.

Paying retail prices, I'd guess the parts would run about $500.00. Not cheap, but not too expensive either. Of course my frame of reference is the complete engine rebuild that I just completed awhile back.

__________________
Don
'85 500SL (Euro) - 186,000 w/a complete restoration and engine rebuild at 154,000
'95 C280 - 174,000

With the exception of the first picture, they are all too out of focus to tell much.

Other than out of focus..looks GOOD!

The goldish color is from the type of oil that has been used.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

If you've gone this far already i'd go aherad and just replace it all, rails, chain, tensioner etc.

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1980 500SE/AMG Euro
1981 500SEL Euro
1982 380SEL
1983 300TD
1983 500SEC/AMG Euro
1984 500SEC
1984 300TD Euro
1986 190E 2.3-16
1986 190E 2.3
1987 300D
1997 C36 AMG
2003 C320T 4matic

past: 1969 280SE 4.5 | 1978 240D | 1978 300D | 1981 300SD | 1981 300SD | 1982 300CD | 1983 300CD | 1983 300SD | 1983 380SEC | 1984 300D | 1984 300D | 1984 300TD | 1984 500SEL | 1984 300SD | 1985 300D | 1986 300E | 1986 560SEL | 1986 560SEL/Carat | 1987 560SEC | 1991 300D 2.5 | 2006 R350

Yup! Same labor putting in new as just replacing the old ones.

You ain't saving any money if 5K miles from now the old rails take a crap.

When you're doing a rebuild remember the old saying, "Penny-wise and dollar foolish" It's YOUR arse you'll be kicking if something goes bad down the road.

I will replace chain and rails for sure. Regarding sprockets I took some more pictures with different camera settings but still the result is not that good. And what about the intermediary sprocket bushings?

Do the whole shebang--rails, chain, tensioner, sprockets. You won't regret it.

__________________
Don
'85 500SL (Euro) - 186,000 w/a complete restoration and engine rebuild at 154,000
'95 C280 - 174,000