M103 timing cover reseal + chain guides

[ps2cho]

Hey guys,

For my 300TE:

Recently switched to Synthetic and my front (lower) timing leak that I had a little leak on has gotten worse. Its not bad, but its leaking more now so its time to do it. Doing my standard research and everything, order parts, then get it done with lots of pictures as always Planning to do it in about a months time once school is over.
Did a search and can't find much on the lower case...tons on the upper, but that was a piece of cake. Lower looks much more involved.

1) MB sealant or Hylomar?

2) I am considering doing the chain guides too...anything particular I need to know about this? Should I replace the chain tensioner or leave it alone? I've read the chains are basically bulletproof, so I plan to leave the original chain in...just replacing the guides.

3) http://www.w124-zone.com/downloads/MB%20CD/W124/w124CD1/Program/Engine/103/01-2100.pdf
Manual states I need to remove radiator and swivel power steering pump out the way. Is this really necessary??

4) Anything else I should consider replacing while doing the job? I have a new fan clutch bearing bracket ready to go too.

Thanks guys

[timmyr]

1) mb sealant is made by loctite . see post#2: Confused about MB sealants (engine mating surfaces) Loctite 5900 Permatex right stuff


2) you’ll need a special tool to lock the crankshaft pulley/flywheel, cause the bolt is torqued pretty high. Although in the link, a forum member mentions that bolt torque = 250-300lbs I double checked my Haynes manual which claims that it should be at 300Nm or 221lbf ft.
see post#8: Crank Shaft bolt Removal M103?????

3) CHAIN: ive also read that the chains are pretty durable, but I would definitely check it to see if there is any stretch(supposedly 5degrees =max.).

Good luck cant wait to see the write up

[hs_300e]

If you plan on removing the lower timing chain cover, it's the perfect chance to replace the front main crankshaft seal.

[Hit Man X]

Reinz has the same sealant as does Loctite, just purchase whatever you can find for the best price.

The tool to lock the flexplate is pretty inexpensive for the M10x and OM60x.

Cannot comment on the radiator removal for the W124, I had mine out on the 300SEL when I did the top end this past winter. I just replaced my front main, super easy and now no oil leaks! I was not in the mood to pull the front cover. Check the stretch of the chain while in there, no easier time to drop in a new chain.

[ps2cho]

Reinz is $10....OE MB is $20, which should I go with?

I have ordered both the regular crank seal and repair size seal just in case.

----

Do I NEED to remove the belt tensioner assembly? I cannot tell if it actually gets in the way or not?

Also where can I find one those locks inexpensively?

[Ferdman]

ps2cho, on a 104 engine you need to remove the belt tensioner assembly to replace the fan bearing bracket. Suspect that it's the same process with a 103 engine.

Removing the radiator will certainly provide significantly better access, even when replacing the fan bearing bracket. I left the radiator in place when replacing the fan bearing bracket on a 104 engine, and it increased the degree of difficulty significantly.

[timmyr]

go with the genuine mb gasket, since this is a pretty big job and it would not be fun to have to do it again.

victor reinz: from personal experience, bought a valve cover gasket 2yrs ago, and it now leaks oil to spark plug holes.

a couple of other people that had problems with VR gaskets: M116 Lower Oil Pan Torque with VictorReinz Gasket??


EDIT: forgot to mention that i replaced the front crank seal about7yrs ago / 30,000 miles ago with genuine MBseal , and it is still holding up well.

[ps2cho]

Actually when I did my 260E's fan bearing bracket, I did not remove the belt tensioner...

That's why I am curious as to why I need to? I guess I will figure it out when I get in there, but I always like to know what I am gonna need to do ahead of time. Its easier for planning and parts purchase.

Will go with OE MB. Thanks. I guess when in doubt, go OE is a good rule.

[ps2cho]

Half way mark!

Found pieces of the guide rail bracket missing, so I decided I needed to do it, but the rail connected to the tensioner was not bad at all...Replaced it anyway since by now I will need to recheck timing.

Oil pan gasket broke off. I do NOT want to drop the pan, so plan is to carefully cut off the section and use the MB timing gasket sealant carefully. I cannot see a reason why this will not work. Worst case, if it leaks, I'll change it next time I change the oil.

Here are customary pics!

I cracked the main crankshaft pulley bolt using the starter and a breaker bar against the frame. Worked like a charm. One click and it popped right off!

[nulu]

Make sure to tighten crank bolt to specs , if it comes loose IT WILL DAMAGE CRANK AND PULLY

[engatwork]

Change the oil pump chain tensioner slide while you are there too.

[ps2cho]

Unfortunately I do not have that slide...
At 115k miles on the clock, I am not worried...I had no plans to even replace those guide rails, but since I had to replace the straight one, the chain had to come off slightly so I went ahead and did whatever I had in my parts box.

I will make sure its tightened to spec, thanks! I hope my torque wrench goes up to 300nm!! LOL.

[ps2cho]

Ugh looks like my torque wrench only goes up to 250nm...

Is there a calculation so I can figure out how much more it would need to reach about 300nm?

[ps2cho]

All done! Found my TW went up to 250ft/lbs so I was good.

Locked crank at flywheel with prybar which worked a charm.

Pics:






I locked the crank using the flywheel and a pry bar carefully. Worked a charm!

[long-gone]

Hey Ps2cho, I know this is a fairly old thread, but I hope you're still around.
I have to do the same job on my daughter's 190E 2.6. I came across this thread and had a few questions if you still remember!
First, How did you make out with the sealing of the oil pan? did the sealant hold up? If it happens to me, I'm going to splice in the front piece of a new gasket with some sealant and only have to worry about it leaking at the splice cracks.
Second, In your pics it only shows the balance and hub attached together. Did you remove them that way or did you take off the pulley and balance first? Was it hard to pull off?
Third, was it hard to torque the bolt down? weren't you worried about breaking teeth on the flywheel or some other damage.

If Ps2cho isn't around or misses this, I'd welcome any other input from someone who's done this before!
Thanks