Let us discuss 603 timing covers.
 

Okay gang, this is for my 603.961 Head gasket failed on it, so I have acquired a reman No 17 head, injectors, prechambers, etc. I have some serious confusion about what timing cover I need to find or purchase new for my setup.

Now, the bottom end has the original timing cover and it seems they have been updated many times by MB as they can crack at the tensioner bolt. Since I am going to install the new head, I may as well do this (yes new timing chain is here along with guides) upgrade while the thing is in pieces.



First PN in EPC for the 126.125 is -

603 010 01 17

603 010 02 17 replaces the previous

601 015 06 01 replaces the previous

BUT if one views the W140 stuff, starting with the 140.135, the timing case is now 602 015 01 01. That is the only one listed.

THEN the 140.134 reads...

603 010 02 17

601 015 06 01 replaces the previous up to engine .971-007421

604 015 01 01 replaces the previous from engine .971-007422



So what the hell cover should I purchase? 601 015 06 01 or the 604 015 01 01 :confused:

603 010 02 17 is 1/5th list price of 601 015 06 01 so go with that :)

Maybe you can make the jump to a rotary vacuum pump!

Sixto
83 300SD

Any idea if one or more has the same internal strengthening?

Which vacuum pump is that? I have the one with rivets on the front.

From mid-97 (I think) the vacuum pump is driven directly off the IP sprocket rather than off a cam on the sprocket. The rotary pump setup has different lube jets in the cover.

Index of /images should have info on some of those part numbers. Check the 602 and 603 folders.

Sixto
83 300D

A '97 OM603?

606. Apparently 601/2/3 and 606 use the same front covers... or generally the same front covers.

Sixto
83 300SD

Dave's site shows the 601 015 06 01 as reinforced for sure.

Either of you guys know if the 604 015 01 01 is reinforced and will fit the 603.961? I believe I know of a used one around, but seeing how the PN does not show under the EPC for my 300SDL (126.125) it makes me very apprehensive to purchase it on a risk.

Get a photo, you will be able to tell from that.

EPC shows the 601 015 06 01 is used on "early" engines and would be correct for any 1980's vintage OM60x engine. If you want a straight bolt-on with no hassles, get this one. (If you haven't checked the price, make sure you are sitting down.)

The 604 015 01 01 was phased in on all OM60x engines later in production, including the 603.960 as of #0049509. Probably around mid-1990's. There is no .961 or .970 engine break as the W126 was out of production by the time the new cover was phased in.

As to what the difference is... if you poke around the EPC enough, on European engines where both the 601 and 604 cover are listed on the same engine, the change appears to correspond with the new rotary vacuum pump. I suspect if you get the 604 cover, you must also get the full late vacuum pump setup, including the drive sprocket/gear/whatever on the IP. Wild guess: the 604 cover may lack provisions to properly lubricate the early vacuum pump? Really don't know, sorry...

:balloon2:

My '91 SD came with the later cover (when I bought it, was not a factory reman but did have a later head). It had the raised area around the tensioner boss (aka: reinforced), and was running the standard / original vacuum pump.

I no longer have the car and have not looked to see if I have a photo of the front cover.

Looks like I will bend over and buy the $400 '601' cover. Thanks all. :)

I have both a 603 015 02 01 and a 603 015 00 01 if anyone wants any comparison pics. There is a difference in the ribs behind the tensioner threaded hole. The first number listed was off a 3.5 factory rebuild.

Sixto's photos are linked in post #4.

Where did you find 601 015 06 01 for $400?? Current MSRP is $1070!!

:eek:

Just for reference I do not see any difference in the 601 015 06 01 vs the 603 015 02 01 at least in ribbing around the tensioner hole.