S-Class (W221) 2007-2013: S 320 CDI, S 350, S 450, S 500, S 550, S 420 CDI, S 600

Idler tensioner pulley

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Old Jan 2, 2023 | 04:52 AM
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‘16 Mercedes GLE450 amg,’15 Mercedes gla, coupe,’07 Mercedes w221,’12 Audi A
Idler tensioner pulley

Well I just had my idler tensioner pulley bearing fail on my S550 and was looking at replacing the whole assembly and noticed that some aftermarket well known brands show the pulley have grooves on the pulley and then oem being smooth. Does it make a difference?


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Old Jan 2, 2023 | 04:57 AM
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S500
the stock one is made of chocolate with a 20k life.....
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Old Jan 2, 2023 | 05:08 AM
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Lol I have noticed but the design make a difference? Groove or smooth? I didn’t go with oem when I first replaced it and went with gates but they seemed to not last a long time.



QUOTE=BOTUS;8695829]the stock one is made of chocolate with a 20k life.....[/QUOTE]
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Old Jan 2, 2023 | 05:36 AM
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Grooves for inside, smooth for the outer surface of the belt. Gates is OEM for pulleys.
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Old Jan 2, 2023 | 05:37 AM
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1983 Nissan Shltbox
And never trust an ad photo. They mean nothing. Just ensure part number match.
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Old Jan 2, 2023 | 05:57 AM
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Senecat ,

Thank you, you are always aces with answers. Happy new year. I just ordered a brand new gates assembly.


Originally Posted by Senecat
And never trust an ad photo. They mean nothing. Just ensure part number match.
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Old Jan 2, 2023 | 08:10 PM
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Any chance you know the part # for the belt idler tensioner pulley mounting torx?

QUOTE=Senecat;8695839]And never trust an ad photo. They mean nothing. Just ensure part number match.[/QUOTE]
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Old Jan 2, 2023 | 09:15 PM
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They are probably using a generic photo in error. Grooved and smooth pulleys are NOT interchangeable. If the grooved side of the belt contacts the pulley, it has to be grooved. If the smooth side of the belt contacts the pulley, the pulley cannot be grooved.
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Old Jan 3, 2023 | 10:26 PM
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‘16 Mercedes GLE450 amg,’15 Mercedes gla, coupe,’07 Mercedes w221,’12 Audi A
Can I just change the pulley? Apparently my mechanic replaced this pulley with a non oem one. I have ordered a gates pulley assembly and also just a gates pulley.
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Old Jan 4, 2023 | 06:39 AM
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S500
its the bearing you need to replace (usually sold as a pulley with bearing pre-fitted) - of course you can just change this, its the only bit designed to wear out as fast as it does
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Old Jan 4, 2023 | 06:43 AM
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Botus,


Awesome information thank you very much. I actually sourced a brand new gates idler belt tensioner pulley locally for $25. So I am going to swap it out as my car has be out of commission since Jan 1st.

Last edited by clb0099; Jan 4, 2023 at 06:52 AM.
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Old Jan 4, 2023 | 06:54 AM
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Originally Posted by clb0099
Can I just change the pulley? Apparently my mechanic replaced this pulley with a non oem one. I have ordered a gates pulley assembly and also just a gates pulley.
Just change everything involved with Gates stuff...parts are pocket change compared to what most parts cost on our cars.
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Old Jan 4, 2023 | 06:56 AM
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Just sucks that it happened as I really finally got this car kinda of sorted and was finally enjoying it trouble free.
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Old Jan 5, 2023 | 12:33 AM
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Sorry, was away for a bit. Glad you got it sorted.
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Old Jan 7, 2023 | 11:58 AM
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All fixed!!! She is up and running once again.
Thank you all!
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