[QUOTE=sixto]We might be mixing who "MB" is. I haven't seen anything in the service or maintenance manuals that says to change the chain at 200K miles. I haven't seen anything that says to align cam marks and read off the crank pulley as a means to determine chain stretch. Lots of sage advise from experienced techs and DIYers have been taken to be gospel... and with good reason.

The proper way to measure chain stretch is in the manual. It calls for instruments most people don't have. Eyeballing by an experienced eye is probably a reasonable shortcut. Taking 5 readings is an excellent way to eliminate variables. How about getting another pair of eyes to agree that the timing marks are aligned? Just to eliminate an area of subjectivity.

Sixto, I'm sorry I wasn't clear, most people on this forum seem to indicate that 200K miles would be a good change interval for the chain. Not all agree, nor do I on this point, it's just repeated by many others.

MB I bellieve calls for changing the chain on the 603 when it is more than 4 deg stretched. This is the advise I'm most likely to follow.

As you mentioned, I do not have all the MB tools needed to measure this with precision, and most indy's as well as dealers in the area are driven by cha..ching. so I took the advise of many other list members on the eyeball check to see whether further investigation is needed.

What I did was turn the engine via the harmonic ballancer with the cylinder head cover off, until the notch on the cam hub (closest to the sproket) lined up with a protruding line cast into the #1 cam bearing cap, 12 O'clock position. When I did this, the timing marks on the harmonic ballancer lined up at 0 deg or the hask mark between the 0 and T.

I agree that a second set of eye's will help, but since arrrg I've gots me only eye...I repeated again another three times with the same results.

Am I doing this wrong? Please let me know how I can recheck the results or test differntly with commonly available tools.

Thanks,
Bill

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1987 300TD 310K mi (Hans)
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