Thanks much for those links. I am going to do the chain. I have a new gasket set and seals. I also have flat bottom thread chasers. One tip I read is to plumb in a drinking straw to a shop vac to clean out the threads. I also got new head bolts.

I'm getting a ceiling mounted hoist from HF this weekend. Kind of amped about the project.

I just used some of my wife's Q-Tips to soak up oil/coolant in each of the head bolt holes, and then chased each hole's threads with a lightly oiled tap. MAKE SURE you chase the threads with the right size/pitch of tap. For the M104 it was M12x1.75 pitch, but I do not know what it is for the M103.

Check your chain rails carefully.

I'm putting my head on the block in the morning. Going to have two men (myself and a friend) do it, along with my son helping final guidance. I will sit on the windshield straddling the motor, while my friend will be in front of the car reaching in.

With my M117 V-8 nearly 4 years ago, I was able to do each head myself as they were much lighter.

Careful on the windshield; they break easier than one thinks.

I rented an engine hoist for a day when I did mine by myself. It was $25, I think.

__________________
Prost!

Good warning, thanks. I actually sit on the windshield mono-wiper. The up-raised hood doesn't really allow one to sit on the windshield itself

gerryvz:

I've read your extensive posts about your top end overhaul and found them very informative! Thanks for your effort.

Several things:

Why no URO parts?

When pulling the head from your engine - how did you attach the hoist? MB recommends at the cam bearing bolts.

Regarding the timing of your cams, I am still unclear about how to make sure I get it right the first time. Can you share more details about how to do this? The past about retarding the cam 30 degrees is very confusing since the 4mm guide pins are to be seated at the block?? Help?

Did you apply gasket sealer to the head gasket?

Thanks for your reply in advance.

Don J.

gerryvz: Any chance of you helping me with the tech info for the M104 cam timing data? Thanks in advance!

You are quite welcome.

Unfortunately, URO doesn't make most of the parts that I needed for the top-end rebuild, so I had to use factory parts. But, URO says they are now an MB OEM, so perhaps in the future they will be offering their great parts through MB channels.

I did not need a hoist. I removed the cylinder head (with both cams still attached) myself by lifting it. A moving blanket placed on the fender and over the air filter area serves as a good resting spot once the head is removed, to rest it on, before lifting it again and carefully placing it on the shop floor or workbench.

The factory procedure and several threads here on PeachParts are helpful and quite clear in nailing the cam timing. Don't worry too much about retarding the cams 30 degrees -- that is just a point in the engine rotation where the cams can be rotated and none of the valves can physically contact any of the pistons.

What you need to focus on is having the engine set at TDC, and the cams both zero'd out with the photos in my post and other posts where the drill bits are inserted into the ends of the cam sprockets. The drill bits MUST be even with the top of the cylinder head. If not, rotate each cam so that it is. Once you have the engine at TDC, and both cams lined up with the drill bits laying across the top of the head, you are in time.

Then, when the cams are set and the engine is still at TDC, but BEFORE you install the timing chain on the sprockets, you need to rotate the sprocket on the driver's side with your hand, in a clockwise motion until it stops. This will probably be about 10-20 degrees of rotation. DON'T rotate the cam itself -- only grab the teeth of the sprocket with your fingers and rotate the sprocket only. This is done with your right hand when you are standing in front of the car, looking over the engine.


That's when you install the timing chain and top guide. I installed a new chain, but you can certainly use your old chain. If your chain has more than 150K miles on it, I'd replace it. Good idea to replace the top guide too - it's cheap.

Does this help clear it up?

No, No, No NEVER use gasket sealer or RTV or anything else. Head gasket alone per factory spec.

For the front timing cover, you need two types of sealing goop for the space in between the cover, head and block (a clear MB sealant) and for the timing cover to the end of the cylinder head (an orange colored MB anaerobic sealant). Don't substitute anything for these -- just get the MB sealants and do it right the first time.

Cheers,
Gerry

Please see attached.

Attached Files

	05-2200.pdf (390.0 KB, 422 views)
	05-2230.pdf (96.6 KB, 357 views)
	05-2240.pdf (137.9 KB, 327 views)

Thank you very much for the tips. I should start this project next week armed with the latest info.

Happy Easter!

OK - got it! No sealer and only use the MB stuff!

Regarding URO, the only issue I had in the past using their stuff was with the motor mounts. They are too stiff and do not isolate the engine sufficiently. After a while my wife was complaining so much that I ordered the OEM items and replaced them again. Should have been more careful.

Again Gerry - thanks for your inputs!

Don

For my real position on URO Parts, check here: http://www.peachparts.com/shopforum/diesel-discussion/347300-dang-you-%FCro-other-tales-woe.html

Understand, thanks!!

Gerry:

Where do you get your tech data on your M104? I use AlldataDIY.com but it is lacking in some areas and I would like to be more through. Also, at the site you use - can you download the entire manual? What's the costs?

Thanks again for your help!