87 420 SEL timing - PeachParts Mercedes-Benz Forum

lifeisabeach · #1 08-30-2006, 10:43 PM

I thought I found it here but I can't seem to locate it now.

I'm looking for a guide [w/ photos would be great] on the step by step procedure on replacing the timing chain, tensioner and guide rails on my 420SEL.

Thanks in advance

Eltee · #2 08-30-2006, 11:26 PM

I would just roll in a new chain and replace the top three guides. Probably a good idea to replace the tensioner too. To replace the guides you have to take the alternator bracket off and the power steering pump. Then you will see the pins that hold the guides in place. You can buy a tool to pull out the pins or you could try to make something.
If it runs good you could probably just get away with the one guide that broke and see how much the chain has streched.

lifeisabeach · #3 08-31-2006, 10:41 AM

I'm definately going to so the chain, tensioner and guide rails, as well as the oil tubes if necessary. There's no sense in not doing it right since it's opened up already.

I remember the process I read mentioned everything you have but I'd like to find that link again. It was a very detailed step by step guide and had photos showing the different steps but I still can't seem to find it.

Eltee · #4 08-31-2006, 10:52 AM

http://www.peachparts.com/Wikka/M117TimingChain

Could this be what you are looking for. Check out the DIY forum

lifeisabeach · #5 08-31-2006, 12:00 PM

YES! That's it.

There was another one that got into the guide rails too but I can't find this stuff now.

I'm searching for the best source for parts too so I can get them ordered. Some confusion on exactly what upper guide rails I need.

lifeisabeach · #6 08-31-2006, 04:51 PM

I ordered the parts today right here on MercedesShop.com

E5004ME · #7 09-01-2006, 02:17 PM

Quote:

Originally Posted by lifeisabeach

I thought I found it here but I can't seem to locate it now.

I'm looking for a guide [w/ photos would be great] on the step by step procedure on replacing the timing chain, tensioner and guide rails on my 420SEL.

Thanks in advance

Check out this thread where Roncallo gave me thorough step by step instructions: 420SEL Timing Chain Guide Replacement

lifeisabeach · #8 09-02-2006, 08:06 AM

THANKS E5004ME for that link & Roncallo for his procedure.

It'll be about mid week before I start this repair but I can't wait

autozen · #9 09-04-2006, 04:14 PM

My advice before you get too heavy into the chain is to pull both covers, rotate the crank with a 27mm, and check the timing marks on the two cams. If they aren't right on, you've jumped timing. Also check for loose rockers on the left bank. If one is loose, just stop there.

lifeisabeach · #10 09-05-2006, 09:31 PM

Parts came today

I did get the air cleaner & cam covers off. The timing is right on but there is excessive slack in the chain due to what appears to be a bad tensioner and the inner left guide rail end broke off. The records indicate a new chain over 100k miles ago but no mention of chain rail guides or tensioner but for $727.30, in 1997 dollars I've got to assume they were all done even though they appear questionable, but.........??

I'm a bit worried that I didn't get new pins nor do I have the specific removal tool but I've successfully improvised in the past where specialty tools are
"required".

I dropped off the left cam cover today to be welded where it cracked so that it's done when I'm ready to reassemble.

It'll be a few days until I get back to it due to my schedule but maybe by the weekend.

lifeisabeach · #11 09-07-2006, 12:39 PM

I checked today when I had a few minutes and there are 2 loose rockers. The movement is very minimal but you can hear/feel movement. All the others are tight.

Remember, it started and seemed to run fine before disassembly, just a rattle w/ 200+k miles.

What do you think?

david s poole · #12 09-07-2006, 01:48 PM

minimal movement on two rockers shouldn't be a problem.when you have bent valves you can almost lift the rocker out of there.