OM617 camshaft advice req'd

[Stretch]

G'day Folks,

I'm in the middle of pulling the engine of my W123 1981 300D OM617 motor apart and I noticed a possible problem with the camshaft.

Can any one advise whether remedial work is required for the following faults.

(My Haynes manual says this sort of thing could be a problem - but it doesn't give a remedy)

The problem I have is that the car has probably sat for ages doing nothing so...

1) Some of the camshaft lobes are discoloured - grey muck on the surface
2) There are specs of rust in the polished lobe surfaces
3) Uneven wearing of the cam lobe followers - when you adjust the valves the gap can be "good" on one side of the contact between follower and lobe, but "bad" on the other side.

I've taken some pictures of the camshaft - I'm hoping the eagle eyed here can see what I mean.

I've got a polishing wheel and compound etc so I could in principle make the camshaft look a lot better - but I don't know whether that would actually help (with any possible problem that I may have).

As usual any help will be greatly appreciated - thanks in advance.

[Diesel911]

As long as the Lobes do not have any large areas flacked off or large areas worn through the hardening that they are wearing adversly they can be reused.

They Followers are going to rinde on the highest spots so some rust pitting on the lobes is not a big issue; with the exception if the pitting is real deep right on the main wear area on the tip.

Where I used to work we would get some 180 Grit Emery (sometimes called wet-dry Sand Paper) and we would work with it on the Camshaft Lobes in a patteren that is about 45 degrees if the direction of the wear pattern that is already there.
If you do that from each side of the Lobe it leaves you with hundreds of Xed patterns acrossed the Lobe.
After that you can follow up with 300-400 grit emery paper.
I forgot to mention that whey you do the above you use light Oil or water.

The above process helps to break up the wear pattern and gets rid of small pitting and rust without altering the demenions.

Since we were rebuilding the Engine and the Camshaft was out we did not have to worry about getting any grit into the Engine.

The same should be done with the Cam Follower wear areas.

From what I have read at some point in time they replaced the Camshafts with ones that had harder Lobes and Followers that were also harder.

I would not worry about the discoloration.

As far as using the Camshaft with Lobes that are worn a little rounded but not pitted or flacked. They can be reused but you will lose a little bit of your Valve lift/opening. This does not seem to be much of an issue on Diesel Engines; unless of course the wear is severe.

[Diesel911]

Concerning the uneven wear on the Cam followers. If the end they pivot on (Bushings or shafts?) are worn out you may find that they will not ever hold their adjustment clearance.

If you intend to reuse them you might have to make a compromise on your adjustment clearances.

[layback40]

Army.
They dont look bad. I have much worse & its not causing trouble.I would do as 911 suggests. You need to get the feeler gauge in the middle when you do the adjustment.

[t walgamuth]

The surface on a cam is hardened so if you have a lobe worn down it is time for a new camshaft. YOu can adjust it and run it for a while but it wont hold up.

[Stretch]

Thanks for the responses I'll clean it all up and see how it goes!

[Stretch]

Edit:-

I took the camshaft to a machine shop to see what they thought - they said I was better off getting a new one with new followers (I had made it clear previously that I wasn't going to buy it from them!)... so that's what I'm doing now. Thanks for your help everyone - seeing things in real life is always different from photographs...

[Stretch]

UPDATE:-

I've got a new camshaft - and hopefully, after a long wait, the followers / rocker arms should arrive tomorrow morning.

Question:-

I read somewhere (possibly in Haynes manual) that the number stamped on the end of the camshaft should match with the replacement.

My old camshaft has a 6

My new camshaft has an 11

Is gonna be a problem?

What do these mystery numbers mean?

(Because now is the time for cow - I can get an exchange as I haven't fitted the replacement yet)

[jt20]

the manual only refers to numbers 08, 00 and 05.

05 being the latest and most desireable.

where did this cam come from?

- if it is new, perhaps it is an even later casting??

[Stretch]

I've proved yet again that I'm sometimes numerically challenged. The old camshaft is actually a 5 (not a 6)

I did remember the other number on the new camshaft correctly though. I splashed out and bought the new camshaft from the dealer.

It is an 11

See picture

[Stretch]

Bump!

Any comments on the 11 stamped into the end of my new camshaft (out of interest only it is going in the car come hell or high water)

[jt20]

found this after some searching elsewhere:

"Did some more EPC research and I believe the following:-
there are only two main basic versions the Early and Late . There are also sub type's which I believe are the same basic profile and are interchangeable with others of the same basic type. Here is my understanding
Type 00 Initial "soft " cam Main Type "early"
Type 08 Replacement cam for Type 00 , hardened Main type "early" , only fitted to a few vehicles
Type 05 New "high Lift" profile introduction, main type "Late"
Type 11 Replacement cam for type 05, main type "Late"
The above goes for both turbo and non turbo as well a G applications"

so, it appears the #11 is a later casting and not mentioned in the outdated fsm.

[Stretch]

Brilliant - thanks a lot for that. What is EPC? I see it mentioned fairly frequently...

[jt20]

electronic parts catalog... I think

you can sign up for free use for a year through MB, but you must give them a credit card.

then you pay for annual subscription

[Diesel911]

I Know that in the US you can have the Camshaft Lobes reground on gas engined Cars.

But, I do not know if they do the same with Mercedes Diesels?

Or is the cost of a new Camshaft close to the reground Camshaft Cost?