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2014 RX 350 F Sport, 2007 Scion tC, 2000 ML 430 Money Pit Finally Gone! Oh Happy Day!
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wfontano said:
Great information guys!

My Harmonic Balancer Pulley just gave in on me (outer shell --- one with grooves - - literally came off) and I'm contemplating in also replacing the Tensioner Pulley.
Dealer replaced my Tensioner Pulley when replacing the HB a couple years ago. All seemed fine to me, but I think they might know more than me about those things. My 2 cents.
 

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ML-55 - 2000,
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Same topic goes in 210 section, that shares the engine.
The tensioner has big hex for pulling the tensioner out and smaller center bolt is locking it.
You need a long box wrench to take the tension off and than you can slip the belt off. I think for easier job you can pull the tensioner out and lock it in this position with smaller bolt, what would leave you 2 hands to deal with the belt, but I never actually tried this method. Sizes wary supposable 13-17 mm for tensioner and smaller bolts come with different sizes and shapes.
Is there a chance that by pulling on the center bolt u might loosen the bolt itself?
 

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1998 ML 320
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Push Hard!!!

Recently installed the belt & the job really took longer to figure out how to put the belt back on properly.

Replaced the plastic, top, "carry" pulley because the old one had split in half and sliced my belt off the car. Popped the cap to expose the bolt -5min job

Using a large & long wrench to push the tensioner so that the belt would go in took a while -from the bottom, one has to push really hard to properly get the belt into place -another person was topside to make sure the belt stays in place -while I pushed on the tensioner, a second set of hands were sliding the belt into place -PUSH REALLY HARD -needless to say, my tensioner is in great shape! -5min

Positioning the belt correctly before and during instalation -15-20min -we even had a diagram printed from benzworld.org!

30min job -not bad for a someone who had never changed a belt before -second set of hands was an uncle mechanic who just helped -would have taken longer if we did not have the correct tools
 

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99 ML320, 2000 ML320
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Just replaced my belt yesterday after reading this thread. Seems like there is some confusion regarding the security torx screw at the center of the tensioner wheel. This screw need not be loosened or removed to replace the belt. Unlike some other serpentine belt arrangements, there is no "locking" bolt. Just use the appropriate wrench or socket that fits on the casting of the tensioner to relieve belt tension. 17 mm socket in my case (99 ML320). My wife's 2000 is identical. Replacing this belt was an easy 5 min job. Definitely helps to have a second pair of hands though.
 

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OK I have done this a thousand times. It doe not matter if your tensioner has the torx in the front. They all have the "nut" as dipicted in this post. Just use the correct size wrench or socket from underneath. If tou want to use the torx then it is a size T50, Make sure it does not require a tamper proof torx. You can tell my looking at the center of the pully, if there is a dimple in the middle where the torx socket goes then you will need a tamper proof torx socket. However as I said before, you DO NOT need to use a torx socket, both type of pullies have the "nut" as dipicted in this post.
 

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2003 ML500, 1987 Porsche 944 Turbo, 2008 Chevrolet Suburban
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Is this information the same for a 03' ML500? I have the belt and need to change it, but want to make sure I have the correct info. I also have the belt route diagram, I just need to understand how to loosen and tighten the tensioner to get the belt on & off! Thanks!
 

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92 SL500, 95 E320, 99 ML320, 98 Harley Davidson's Low Rider & Wide Gluide
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O.K., driving home last night battery light came on & lost my power steering. Open hood, & belt is off all the pulleys. Checking the movement of all the pulleys, all turn normally with the exception of the tensioner pulley. I can move it forward & backward (is this also called the harmonic balancer?)

Do you remove the entire tensioner or just the pulley? My 99 320 appears that the tensioner is held on with male torx .

thanks

al
 

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2006 ML500 2002 ML320
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O.K., driving home last night battery light came on & lost my power steering. Open hood, & belt is off all the pulleys. Checking the movement of all the pulleys, all turn normally with the exception of the tensioner pulley. I can move it forward & backward (is this also called the harmonic balancer?)

Do you remove the entire tensioner or just the pulley? My 99 320 appears that the tensioner is held on with male torx .

thanks

al
The tensioner pulley is just that, a tensioner pulley (#1 in illustration). The harmonic balancer (#2 in illustration) is also called the crankshaft pulley, but does not turn unless the eng. is running.

The tensioner pulley must spin freely and if it does not it must be replaced.
 

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92 SL500, 95 E320, 99 ML320, 98 Harley Davidson's Low Rider & Wide Gluide
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43sqd, thank you very for that info. Looks like I'll have to invest in a set of torx wrenches.

It looks like everything I've read in this forum is starting happen to my ML as it approaches 100k (93k).

Does anybody know of a good independent in the St louis area? SL has a blown head gasket.

al
 

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Original tensioner with metal pulley does not have this 17mm boss. You have to loosen tension using E10 stud in center of the pulley.
 

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Question: My serpentine belt came off and my idler pulley split in half. I have read the above- and the answer that the common man who knows about cars can change a belt has been answered, but can non experts also change the idler pulley, and if so, can this all be done from under the car or what have you, without removing the fan cover, etc? Please explain the steps from replacing the pulley.

Also, strangely in the same moment I lost the ability to open my hood from the cable release inside and had to bust through the grill to open. Do you think it is coincidence, or that something greater may have happened that cause all of these things to happen at once. Note, car still drove, but with a whistle and no power steering. The belt was wrapped around the power steering and wedged deep into the lower right pulleys.

My only car and I need to fix asap, but don't want to pay the mb shop $500 to do so!
 

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2003 ML500, 1987 Porsche 944 Turbo, 2008 Chevrolet Suburban
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Yes, you can do it, you will need a breaker bar with star socket to get the idler pulley back from underneath. Also when you remove the old pulley, the bolt is long and you will need to move the fan just right to get it out, at least on my ML500. As far as the hood pull not working, I would say that it got injured from the belt coming off, when mine came off, it ripped up my dipstick. I purchased my pulley and gates belt at carquest, and it was much cheaper. The tools you will need, if you do not have them are invaluable and will not cost you much and you WILL need them again someday!
 

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crankshaft pulley...

after reading with interest these threads i have come to conclusion with the problems of my car today that the crankshaft pulley wheel has come off.
i lost steering and batterly light came on and the distinctive burning rubber smell.....i checked inside and not only is the belt off but the large wheel looks to be off and rattling....
i am going to confirm this is the right wheel via a diagram i found on here but if it is cant the crankshaft flywheel be easily replaced and how.....
cheers all
gary:surrender:
 

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crankshaft wheel...

its just gone 11 in uk.....snow and freezing and i went out and checked which wheel was broken....yes its the crankshaft wheel......the belt is off and its really strange.....its as if there is a whee with brooves on it going around a smaller wheel.....the wheel with grooves on have come away and can be actually taken off the inner wheel.....this does not look good....
how is it meant to be attached and can it be replaced simply....
cheers all
gary
 
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