801

Has anyone had their W212 M276 equipped Serpentine Belt replace yet? Better question would be ... has anyone done this themselves? I'd like to do mine.
W211 Serp snapped on my at 76k W212 M276 is right at 73k.
If you've done yours (again, M276 W212, not M272 ....) any tips or tricks would be appreciated AND .... I would REALLY appreciate a Serp belt diagram. Konigstiger circulated one a while back but it had every iteration of new DI engine Serp belt routing and I could never determine which diagram was actually relevant to our US W212 M276 3.5 DI engine.
thanks in advance.
For the record, 2012 E350 4matic M276 73,212 mi and going strong.

konigstiger

Belt part # 0029930996

cetialpha5

Just take some pictures of the routing before you take off the belt. Refer back to the pictures when you put it back on.

801

Thanks for isolating that correct diagram, Konigstiger. Much obliged.
So again though, before I dive in blind, has ANYONE done there M276 Serp belt yet? Or do I have the highest mileage W212 M276 on this forum (77k mi)?
Shirley, there must be a few tips and tricks to make this go well .... like some bits and pieces to remove for better access .... and what is that, a 17 mm socket that is used on the tensioner to 'un-spring' the tension/belt for removal ??
And move my breaker bar (with 17mm) counter-clockwise, correct? to relieve tension?
Any tips at all would be appreciated ...

and thanks again for that diagram.

Quattrodude

Its really easy - I have done it 2 times on the V8's and there is less room - but its just a matter of threading it around correctly. As before just take good pics. I had my SO help with the last part where I needed tension put on the tensioner...but that was it...prob took me 5 mins? (just watch the fingers when releasing the tension)
Switching a wheel out is harder LOL...

Good luck

300SE1993

I just did it on my M272 as part of the motor mount job. I took pictures ahead of time, but it's surprisingly easy. I used a regular 17MM socket on the tensioner. I threaded as much of the belt as I could without the tensioner being loosened, and left the last bit on the bottom right (AC Compressor on mine). At that point, I loosened the tensioner and was able to slip the belt over the AC compressor pulley and then line everything up. It should not take you more than 5-10 minutes if you take your time.

kajtek1

Belt routing is in manual.
In case you don't have it available, the main rule is that the belt comes CW under main pulley and makes about 160 degree loop going to next pulley.
Once you get it started this way the rest is easier to figure out.
On engines with no engine fan (electric on radiator only) belt replacement is child's play, but you still need good wrench with long arm for tensioner.
Also most tensioners have hole for holding pin. Small screwdriver works, but need to be good quality.

801

Okay, done deal. I appreciate all the support in the above replies/responses.
Konigstiger M276 Serp belt diagram was 100% accurate. (thanks)
Couple of tips:
1. 17mm socket is what is needed for Tensioner. Fortunately I had a 28 inch ratchet breaker bar which made de-tensioning a real breeze.
2. I removed the top-front engine cover ... as well as the hard plastic air-intake snorkel "elbow" piece (that connects the front air-intake to the actual air-filter housing.
3. Removing those 2 items really REALLY exposed the belt and engine-front ... making access really REALLY easy. Plenty of elbow/hand room. Plenty.
4. Tension is relieved by moving breaker-bar ratchet + 17mm socket COUNTER-Clockwise (meaning ... to the left when facing front of engine)
5. Old belt just slips right off ... new belt (following above diagram from Konigstiger) slips right on.
6. Nearly all of the pulleys have lips on them, making this a real no brainer.
7. Lastly, approx 75k mi and the original Conti belt looked brand new. These m276 serp belts are a HUGE and VAST improvement over the M272 serp belts. My original belt with 75k mi had zero wear and tear, zero cracking, zero scuffs, etc. But since it was off ... replaced it with brand new OEM Conti.
8. I'll keep the original one in my trunk tool bag.

thanks again, all.

Billyismyname

My 2014 E350 has 124,500 miles on it and has never had it's belt or water pump changed out (knock on wood, it's never had any issues yet). I plan on buying all of the pulley's, the belt, and the waterpump this week. But yes, super easy job to do!