timing chain ID question - PeachParts Mercedes-Benz Forum

gatorblue92 · #1 10-20-2011, 12:20 PM

I'm in the process of adjusting the valves on my 84 300D with a 617 engine and the timing chain has marks on each link. Is there any way to tell by the marks if its an original or a replacement? The marks all read JWR.

leathermang · #2 10-20-2011, 12:38 PM

The original will have no master link.

47dodge · #3 10-20-2011, 06:17 PM

I was wondering this also. Although I thought you could get a replacement chain that does not have a link, and is riveted together? I know linked chains are available.

My timing is right on, so either I have an offset link, or new chain. There is no master link, so I am wondering which I have. guess I should take the cam bolt loose and see what key is in there,

leathermang · #4 10-20-2011, 06:27 PM

You can get and install a chain with no master link.... but you will then be certifiably crazy...
LOL
You would have to take apart the entire front of the engine stuff... that is how it gets on at the factory.... EEEEEEKKKKKKK!!!!
So you are just sitting around with all things hunkydory... timing right on..... thinking.... what can I take apart ?
Take apart your glove compartment or your evaporator and clean the fins on that.....
This ' I am afraid of using the crimped pins to hold the master link together ' is silly and unnecessary handwringing... it is very simple and legit machine design.... just be sure to replace everything which is in contact with the chain in its operation mode... most chain problems come from those things not getting replaced regularly...

47dodge · #5 10-20-2011, 07:16 PM

No I am not sitting around thinking of things to do, have a bit much to do as it is.

I did some looking on this forum and did find a replacement chain can have no master link. So just looking at the chain for a master link does not guarantee it is or is not a replacement. Just that if a master link is found then it has been replaced, and if a master link is not found then you have to wonder.

gatorblue92 · #6 10-20-2011, 08:09 PM

Well no master link but only 3 degrees of stretch... This car is so odd. It reads 346k on the odometer but some wear items can't have that amount of miles and now a seemingly good timing chain.

DeliveryValve · #7 10-20-2011, 08:29 PM

Quote:

Originally Posted by gatorblue92

... The marks all read JWR.

Actually it is JWIS, which is the same as IWIS. They are the OE manufacturer of Mercedes Benz timing chains.

Usually the master link is a blueish color and it can come in as the same color as the chain. It can be carefully crimped in place so it looks like there is no master link. So looking for a master link could be hard to spot.

On the older factory chains, the rivets had a dimple to them. While the later chains have two sides of the rivet flattened by the crimper.

.

vstech · #8 10-20-2011, 10:30 PM

and if frequent oil changes were followed, and long highway drives were the norm for the car, it's quite possible for a chain with 300K+ miles on it to only show 3degrees of stretch... but it's unlikely.

Diesel911 · #9 10-20-2011, 11:56 PM

Quote:

Originally Posted by 47dodge

I was wondering this also. Although I thought you could get a replacement chain that does not have a link, and is riveted together? I know linked chains are available.

My timing is right on, so either I have an offset link, or new chain. There is no master link, so I am wondering which I have. guess I should take the cam bolt loose and see what key is in there,

The IWIS Master Link (that you need to rivit) is a different color from the rest of the Chain.

There is no offset Link but there is offset Keys. So it is possible for an old (worn) Chain to look like it is a new one by the degree marks but the offset Key has corrercted it as far as the degrees go.
The only way to know is to loosen the Camshaft Drive Gear enough to view the Woodruff Key.

Diesel911 · #10 10-21-2011, 12:04 AM

If you look at the 2 items circled in Red you see that the Euro Writing or Logo looks somewhat like JWR but the internet site has IWIS.

The Gears · #11 10-21-2011, 03:40 AM

I have a high mileage 84 300 SD, 384Miles. Chain stretch is almost nothing. I attribute this to full synthetic oil since available. Lots of oil filter changes. Not running the oil too long. 55 miles each way on the freeway almost every day and what I think the most important chain saver. Avoid high RPM. I drive just under 3000 RPM on the freeway. with the 2.88 dif. that gives me around 70 mph.. Fast enough for me.

gatorblue92 · #12 10-21-2011, 05:28 PM

Quote:

Originally Posted by Diesel911

If you look at the 2 items circled in Red you see that the Euro Writing or Logo looks somewhat like JWR but the internet site has IWIS.

That's it. My eyes aren't the best

Quote:

Originally Posted by vstech

and if frequent oil changes were followed, and long highway drives were the norm for the car, it's quite possible for a chain with 300K+ miles on it to only show 3degrees of stretch... but it's unlikely.

This is good to know. After doing some digging on the car it lived in Deltona, FL and made frequent trips to Miami for most of its life till it was traded in and sold at auction to a dealer here in Mississippi who sold it to the person I bought it from.