Simple Timing Chain Questions - PeachParts Mercedes-Benz Forum

#1 01-11-2003, 04:19 PM

Hello everyone!

Reading the posts re timing chains, I still am quite unsure as to what REALLY causes that seemingly sturdy part to go bad/stretch... So what does?

Secondly, what are the symptoms of having abnormal/out-of-spec chain? Is it possible to immediately recognize this problem?

Lastly, is changing the timing chain a DIYer? Or does it require some special tools which are hard to come by?

Thanks again!

-DON

waybomb · #2 01-11-2003, 05:05 PM

The links of a chain don't really strectch, but the chain does get longer, thus, the term stretch.
What happens is at each hinge point, that is, at each chain link, there is a pin. That pin is metal, just like the link. As the chain travels across the sprocket, the links hinge, and there is mechanical action beteen the pin and the link. Over time, the pin wears just a tad, and the link wears just a tad. Considering how many links there are in a chain, you can see that even a half-thousandth wear at each pin can add up to quite a bit of length, thus, the term that indicates this becomes stretch.

P.E.Haiges · #3 01-11-2003, 09:53 PM

But a better term than stretch would be elongation caused by wear.

I consider it DIY job because I have done it my self. But it takes at least 2 people and preferably 3. The only hard part is peening the pins on the master link. The last one I did, I had a master link
with the spring clip so peening was not necessary.

P E H

Stevo · #4 01-11-2003, 10:24 PM

Don

I did it with my wife helping and the hardest thing for me was putting the side plate on the new chain (connecting the old and the new) then getting it back off when the new chain was 'cranked" through and then putting it on to connect both ends of the new chain. Thats twice on and once off. I found the peening easy using a body & fender tool as a backer upper and of course a ball peen hammer. The side plate is a tight fit. Now that I have done it once, next time its gona be allot easyer

leathermang · #5 01-11-2003, 10:27 PM

PEH, ok when the three people are there... what is each doing ? I can figure out two... I assume you do not mean the third is for bringing finger sandwiches and lemonade to the other two....

leathermang · #6 01-11-2003, 10:34 PM

Don, here are some of the threads which have explored this topic lately....

http://www.peachparts.com/shopforum/search.php?action=showresults&searchid=320214&sortby=lastpost&sortorder=descending

lots of good stuff in them.....

P.E.Haiges · #7 01-12-2003, 12:48 AM

Leather,

Nope, no food or lemonade.

One to turn the crankshaft from below. Since I have a pit in my garage, that's easy. Daughter turned crankshaft with ratchet.

Two to guide the new chain over the camshaft making sure it doesn't jump a tooth. That's my job.

Three to pull old chain out of engine so it doesn't slip back in. Wife did that.

It can be done with two people but if three are available, its easier and safer (prevents possibility of old chain slipping back into engine). Thus was done on a 220D but other engines should be similar.

P E H

leathermang · #8 01-12-2003, 12:56 AM

PEH, That sounds like a good arrangement.... and having a pit to work with is really great...
As a one person garage..... I plan on making a motor driven crank turner... worm and gear arrangement .... not just for that.. but also for valve setting and chain elongation measurements...I can find one helper at a time to get greasy... but two out in the country is not easy....

240 Ed · #9 01-12-2003, 08:52 AM

Quote:

and the hardest thing for me was putting the side plate on the new chain (connecting the old and the new) then getting it back off when the new chain was 'cranked" through and then putting it on to connect both ends of the new chain. Thats twice on and once off.

Stevo

I thought I was the one who originated the peening idea!

To save you grief next time, go and get yourself a master link for a gas engine, like a M108 or M130. It uses the familiar clip and is a smaller gauge than the diesel, so it is easy to use. (the pins are a smaller diameter, so they slip through the diesel chain easily) The "pitch" is the same though, so it lines up with the sprockets okay.

Then after you have fed the chain, use the "real" master link for the final peening chore.

leathermang · #10 01-12-2003, 09:52 AM

That is an excellant idea... Who knew the gas pin was smaller ?

240 Ed · #11 01-12-2003, 09:57 AM

Greg,

It is because I know all !

In reality I found out by accident. I was looking for the clip type of link, and the parts guy at my local BAP store sold me one, swore that it was for a diesel, knew what I meant, etc.

Well, if it was for a diesel chain, it wasn't for MY chain, so I figured it must be for the smaller gauge gas engine. (I am ASSUMING it is a smaller gauge...)

Anyway, take the link that comes with a new chain to the store with you, and compare.

P.E.Haiges · #12 01-12-2003, 12:01 PM

Leather,

Yes, the pit is worth more than its weight in concrete but that's about all it cost, 4 or 5 yards of concrete. I built it myself about 15 years ago. I would recommend one for anybody who is a DIYer.

Its been used for engine and transmission R&R, brake jobs, drive shaft and flex disk work, front end work, fuek tank filter cleaning, multi oil changes, exhaust work, ETC. Sure beats laying on your back with dirt falling in your face.

P E H

Stevo · #13 01-12-2003, 01:36 PM

Lots of good info in this thread.

Ed thats a good idea you came up with. the clip type are easy to endo but secure enough so you wouldn't worry about loosing it

down the 'hole" then? I like that.

PEH

I wish I had done a pit when I built my shop years ago. Could you tell us a little about it and what you would do differant if you were to do it again, if anything. I might build another shop dedicated to car stuff as woodwork and greese dont mix to good.
3 to 4 yards, wow, a bomb shelter too

leathermang · #14 01-12-2003, 03:07 PM

PEH, I would like to Ditto Stevo's question about specifics... what LWH is yours... and if you had it to do over what would you change , If anything ?

Stevo · #15 01-12-2003, 04:46 PM

leathermang

Ya, I would be more into using a backhoe if I do one these days. One thing for sure is in this country it would need to be sealed or it would be my extra short lap pool in the winter.