OM603 broken cam tower bearing - PeachParts Mercedes-Benz Forum

dieseldiehard · #1 10-01-2013, 11:58 PM

I bought a rodbender for its head to replace the #14 thats on my '87 300D, not because its bad just I want to upgrade to the angled injectors also I see a small amount of oil leaking from one corner of the head so a new headgasket is in order eventually.
I'm unsure of what initiated the failure but the donor 603.971 rodbender failed pretty dramatically: the timing chain broke and a piston struck an intake valve, bending it, the cam snapped into three pieces and one upper cam bearing also broke. The backside of the cam sprocket also has a chunk missing but the teeth are still there. I have a good cam I got from eBay with sprocket.
Note that I want to keep the cam and bearing caps for my good #14 head in order to sell it as a complete set so I don't want to rob a cam bearing off it.

What I am wondering is will a dealer supplied bearing cap fit or will I need to machine it to fit?
Never been down this road before just wanted to hear from someone experienced in this. I've heard of line boring the cam bearings but I thought that was only if the head was warped significantly. This one was not overheated and checked straight, it meets all tolerances but I did have to add shims under the PC chambers to maintain the spec for protrusion into the combustion chamber.
BTW the head was repaired with all new valves (even though only one was damaged, this was an option I took to make it 100% good).
DDH

vstech · #2 10-02-2013, 12:05 AM

I've got a damaged 602, lemme know if one of it's cam caps will work

dieseldiehard · #3 10-02-2013, 12:26 AM

OK, thanks! I probably have something to trade! p/n is 601-051-00-03

scottmcphee · #4 10-02-2013, 09:11 AM

So you're taking the head off a car that snapped its cam shaft and busted the towers? I'd move on, personally... That sounds like you might be facing other issues with fit and bearings, no?

winmutt · #5 10-02-2013, 02:12 PM

I have spares.

dieseldiehard · #6 10-04-2013, 02:06 AM

winmutt, did you see the p/n? got one? what can I trade you? shoot me a PM, thanks!

winmutt · #7 10-04-2013, 07:47 AM

Interestingly enough the dealer cost on this is $41. PM sent.

ngarover · #8 10-06-2013, 07:11 PM

I have a full set of these sitting here also. Just let me know if you need one. I also have an extra cam.. But it's got to be polished. It was in a truck and got wet. Surface rust only.

dieseldiehard · #9 10-13-2013, 01:32 PM

sweeping up after sending my S350D carcass off to the scrapper, I found a cap! I don't believe it came off this car though, it was in one corner of the garage, there it was just waiting for me and my broom!
So thanks to all that responded, I would have been kicking myself if I had bought one from y'all then found the one I found yesterday.

sixto · #10 10-13-2013, 01:55 PM

For kicks, set a strip of Plastigage under the replaced cam tower and an adjacent cam tower to compare clearance. Or would you rather not know?

Sixto
87 300D

dieseldiehard · #11 10-13-2013, 02:51 PM

hi Sixto. Got no plastigage. I was concerned that the odd cam bearing might be a different fit. will mount the cam before I install the lifters and see how it spins.
I showed the cam bearings to Gus, he applied a little polishing compound to one of the bearings that shows some grey coating on some, nothing you can feel with a fingernail.

sixto · #12 10-13-2013, 03:14 PM

C'mon, man, Autozone sells Plastigage for $2.50!

http://www.autozone.com/autozone/accessories/Sealed-Power-025-075-mm-001-003-in-green-plastigage/_/N-25xn?itemIdentifier=202588_0_0_

Sixto
87 300D

dieseldiehard · #13 10-13-2013, 03:26 PM

maybe I'd rather not know!! if I can spin the cam around with no dragging I'll be happy