1986 300E head rebuild/cam replacement

My car has 210,000 miles on it.
I'm getting ready to have the head reworked on the deutchee-wagon, and I need to know if it will make a difference as to whether or not I replace the camshaft before or after I have the head reworked? I'm also wondering what would be standard operating procedure when replacing the cam- what other valve train components should be replaced (besides the rocker arms, lifters, valve stem seals, and valve guides). Should the valve springs be re- placed? Also, after having replaced the aforestated components, would it be O.K. to drive the car to the local shop (35 miles)to have spacers installed if needed?
Thanks,

Joe Slemp

[mbdoc]

What's wrong with the camshaft? Replace the valve springs any time they are removed. Just what "shims" is the other shop going to install? If the timing chain & tensioner are original then replace them too.

[Benzmac]

Have it all done at once. If the head needs work the cam will have to come out anyway! You could also need some new rockers. As DOC said always replace the springs.

------------------
Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

MBDOC,

I had already pulled the valve pan cover to change the valve stem seals; and upon inspection, noticed that two of the cam lobes had been shaven. Another lobe was scored rather badly. The "shims" I spoke of are the spacers that would take up any clearance between the valve stem and the lifter (if needed).

After speaking with the machine shop that will do the repair, I understand that since the valve seats are going to be recut, that shims may not be necessary at all since they'll probably have to shave the tops of the valve stems anyway after recutting the valve seats.

So I'll be rebuilding the head with: new valve stem seals, lifters, (valve springs), camshaft, rocker arms, valve guides, and what else.... With 210,000 miles, it's probably advisable to mic the cam bearings as well to see if they are still within tolerance. Or is it possible just to bore them and go with an oversize camshaft? I suppose I could go with new cam bearings if need be; but my wallet cringes at the thought of that. What do you think?

Thanks,

Joe Slemp
1986 300E

[Benzmac]

There are two different pieces that could be called shims in the valve area. Both are very important and are needed. Only one has a repair size. One piece of advice, ONLY HAVE THIS DONE BY A MERCEDES TECH OR MERCEDES KNOWLEDGEABLE MACHINIST.

------------------
Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

[Benzmac]

Thanks for the informative e-mail. I was not aware of the valve ajustment shim having adjustment sizes. I have only seen the lifter sockets in different sizes.(Sorry I'm not a machinist.)
The only thing that must be done in my experience is the replacement of the cam and rockers together. The rocker stands will be fine.

------------------
Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM