I see now... thanks for the information! part highlighted #70. I'll order this part on Monday. 😀

 

Last week the belt snapped , I had replaced the aluminum weistec pulley bearing around 800 mile ago .
upon inspection the pulley had side to side movement , I think that broke the belt .
Anyone know the right bearing number ?
thanks

 

remove the pulley and look at the bearing. the part number will show as well as brand of bearing.

 

well...tomorrow is going to be a busy one...

so glad my full sized tap and die set has thread pitch measurements as well. the time serts should fit fine.

 

Post up pics of that billet pulley piece

 

we're back in business! I always wondered why the right most pulley's bolt went in so easily...it is because that bolt hole was already upgraded to a time sert. 😂

tomorrow I'll have the new bearings pressed into the aluminum pulley's and swapped back on.

after my engine warmed up enough I gave it a few revs to confirm the belt was on solidly...I totally forgot I had loaded my E85 burble map and startled myself with the pops out of the rear. 😂😂😂

 

Excellent repair job!

 

You have the nicest Tap handle i have ever seen!

 

These are how mine were 3 years ago after about 140k km (87k miles).


Should probably check them again.

 

throughout the years...i've had to buy onzies and twozies of tools...really got fed up so now i just buy complete kits. this handle is part of a complete kit from gear wrench...not too pricey but has paid itself back over and over again. i literally have enough speciality tools to open up a smaller shop of my own.

 

Ya I hear you I have drawers of specialty stuff from 20 years of fixing special cars, thought i had about all I needed and then tried to remove my rear bumper on the C63 - you need a 6 inch deep 10mm socket for that btw!

 

 

Ok, since you guys all scared me, I did all my idlers and the tensioner today, after new CA's cams and lifters, tensioners were the noisiest thing on the car! Belt was new already, but wow some of those bearings once off were so dry and noisy with only 39k miles on the car (it is a 2014), Glad I did them, seen stuff with 100k miles on it that was in better shape than these things!

 

I did all mine except the tensioner as I could not get it past the fan shroud.
The bearing felt ok so I left it till next service time.
How did you guys get the tensioner out?

 

Lift out the fan. It takes about 10 extra minutes.

I don’t know how you guys do those with the fan in, nevermind getting a proper torque wrench on the bolts.

 

I tried getting my fan out but kept fouling the radiator hose.
I actually deformed the hose to radiator attachment slightly but was able to round it back to shape and so far no leak.

 

If removing the fan is as easy as doing it on the M113 that should not be a problem. Using the correct MB wrenches to do the job is a time saver IMO

P.S. The extensions attached to the lower tool are NOT MB originals...

 

Had no issues going out the bottom with it, I have the luxury of a lift, but ramps would be fine, did the bottom idler and the tensioner from the bottom much easier to get to than from the top and it slipped out the bottom pretty easily (and I had the lower idler off when I did it which may have helped a little). Thing that took me the longest was getting that plastic cap off the smallest pulley above the crank pulley that took me longer than rest of the pulleys I think!)

 

I took my tensioner out through the bottom as well.

 

Thanks I'll try going out the bottom next time.
Getting those plastic caps off is a pain also.

 

Looking through my service history, these have never been done.

I’m at 130K, there’s no play in any of the pulleys should I replace anyway?

 

I would as a precaution.
I did all mine (except tensioner) in 2018 with OEM plastics but I will replace them all at next service when hopefully I fit the new tensioner.
That will be in August or earlier depending on klms travelled.

 

Are those that are experiencing failures installing with a torque wrench? Excessive tightening can cause distortion on the bearing's inner race causing excessive heat which could lead to premature bearing failure and/or embrittlement of the plastic. I'm about to replace all the pulleys and belt as a precaution. Just looking for any missing data that may give some insight into avoiding a future failure.

 

Hey Barry, how are your NTN bearings working out? I’ve got the car in pieces chasing down a few things, and noticed that the billet tensioner pulley has a pretty good side-to-side wobble to it. Have a new tensioner here anyway, but I’d like to put the billet pulley back on. If I’m going to replace one bearing, might as well do all of em (they all feel ok, maybe just a little tight).

Also, to press the bearings in. I have a hand bearing press here I’ve used for my bikes hub and head tube bearings. Pretty standard equipment, plates on either side with a big bolt down the middle. Same kinda thing works for these, or am I gonna have to take them to a machine shop for a real press?

Thx

 

if they feel tight I would change them...my suspicions are the grease begins to go bad over time causing stiffness which then causes galling. the NTN bearings I have replaced mine with have a higher rpm operating range so they should indeed last longer than the previously installed bearings, but only time will tell from here on forward. I spent a lot of time trying to identify a bearing with an even higher operating range but was unable to find such a bearing. I'm not exactly sure if it's the grease or the tolerances which raise their operating range as they're both C3 toleranced. the NTN's are about 3x the cost but worth it if it saves me from a headache going forward if they do last longer.

at some point I'll have to plop those aluminum pulley's back on as they now have new NTN bearings pressed into them. right now only my tensioner is an aluminum pulley.