OM606 NA Belt tensioner?? - PeachParts Mercedes-Benz Forum

freesoul · #1 11-02-2014, 07:35 PM

I noticed the tensioner pulley is way out of alignment, I had the tensioner replaced about 2-3 yrs ago by local shop, they replaced the whole arm because I had the old part at one time- not sure about the shock or spring.

Do I need the whole assembly or just the pulley and bearing? Any tips on replacing it? TIA

TMAllison · #2 11-02-2014, 08:58 PM

Looks like the roller pulley isn't aligned? Is available separately. Drop tension on the spring and see if its bearings are fried. Guessing they are bad.

freesoul · #3 11-03-2014, 10:07 AM

Quote:

Originally Posted by TMAllison

Looks like the roller pulley isn't aligned? Is available separately. Drop tension on the spring and see if its bearings are fried. Guessing they are bad.

Last Friday I ordered a new pulley should have it today. Hoping that is all that is needed. Do I have to remove the whole arm assembly to get it out?

TMAllison · #4 11-03-2014, 11:41 AM

after you drop tension on the spring and remove it, you ought to be able to push/pull the pulley such that you can get a socket on it.

The tensioner arm requires a 17mm hex (might be 19mm, its been a while), access is limited. I was able to remove it by removing the radiator cross member, unclipping the rad and pulling it forward an inch or two. The fan has large and small fan blade spacing's, rotate it to a large opening which gives enough room to get the hex into the tensioner then use a wrench on it cause you prob won't have room for a ratchet. Put some cardboard against the rad fins to protect it and your knuckles too.....

courtney · #5 11-03-2014, 12:29 PM

question about the tensioner set up

i did the spring and the shock 30,000-40,000 miles ago but my mechanic did not think the "arm" at the bottom needs replacing

that it is just a metal piece and does not need to be replaced unless cracked, worn out and not tight on the pivot part at the bottom, etc

is this correct?
the shock and spring are the wear items?
and the bottom metal part does not need to be replaced as often?

Zulfiqar · #6 11-03-2014, 01:11 PM

Quote:

Originally Posted by courtney

question about the tensioner set up

i did the spring and the shock 30,000-40,000 miles ago but my mechanic did not think the "arm" at the bottom needs replacing

that it is just a metal piece and does not need to be replaced unless cracked, worn out and not tight on the pivot part at the bottom, etc

is this correct?
the shock and spring are the wear items?
and the bottom metal part does not need to be replaced as often?

The arm itself has a bushing in it that rides on the pin that is tightened in the timing case, The arm bushing does wear out over time and it only wears out in a little area only - a worn bushing causes noise as the arm rattles on the pin.

btw freesoul - you might want to check out the walmart cleaning aisle for "mean green" to clean up the oily mess you have there. It works really great to clean old baked on dirt loaded grease..

winmutt · #7 11-03-2014, 01:14 PM

Are you possibly missing the spacer behind the arm?

freesoul · #8 11-03-2014, 03:50 PM

Quote:

Originally Posted by TMAllison

after you drop tension on the spring and remove it, you ought to be able to push/pull the pulley such that you can get a socket on it.

The tensioner arm requires a 17mm hex (might be 19mm, its been a while), access is limited. I was able to remove it by removing the radiator cross member, unclipping the rad and pulling it forward an inch or two. The fan has large and small fan blade spacing's, rotate it to a large opening which gives enough room to get the hex into the tensioner then use a wrench on it cause you prob won't have room for a ratchet. Put some cardboard against the rad fins to protect it and your knuckles too.....

thanks, I got the replacement pulley and am hoping to just be able to unbolt that rather than take the whole arm off. Not sure what bolt size, pulley didn't come with it..... out to the garage later tonight and hope its just a standard bolt and not a hex so I don't have to buy more tools

Maxbumpo · #9 11-03-2014, 04:20 PM

Looks to me like you need the entire assembly (i.e. pivot arm). The pulley wheel and its bearing rarely go bad, it is much more common for the pivot bearing on the arm to wear out.

freesoul · #10 11-05-2014, 10:47 AM

both bearings were bad, I got a new arm and shock absorber yesterday and need to install today. Paid $20 for a 17mm hex socket from snapon truck, no where else locally had one that big

Zulfiqar · #11 11-05-2014, 12:15 PM

Quote:

Originally Posted by freesoul

both bearings were bad, I got a new arm and shock absorber yesterday and need to install today. Paid $20 for a 17mm hex socket from snapon truck, no where else locally had one that big

autozone sell a 3 piece hex set with the 17mm in it. takes a 1/2 inch drive ratchet.

When I replaced my cars item I took out the radiator completely (good reason to clean its fins and also the condenser fins)

did you buy a genuine mercedes part or a replacement? - when you take it off make sure the pin is not ground out. if it is then you need the pin too. Meyle etc. make a replacement part but its not worth spending the 40 dollars because it starts to rattle again in a few months.

Jeremy5848 · #12 11-05-2014, 12:24 PM

Also note that both front and rear seals are important if you want the new "bearing" to last. The front "seal" is just a plastic cap that looks decorative; the rear seal is often missing. EPC shows both. The seals keep water out of the bearing.

freesoul · #13 11-06-2014, 10:18 AM

the replacement bolt on the website of my local parts place says its made by Laso..... same indy MB shop that replaced the tensioner last time.... starting to think I should get genuine MB part.....

freesoul · #14 11-06-2014, 10:48 AM

I decided to stay with the one I ordered and pick it up today at 3pm. My next question is should I put any WD40 or grease on the bolt or leave it dry?

engatwork · #15 11-06-2014, 11:03 AM

Iirc the threaded part of the bolt calls for sealant where it threads into the timing cover.