Dampened pulley vs. Non
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Junior Member
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From: Minneapolis MN
'03 C32 LET Stage I
Dampened pulley vs. Non
I have LET Stage I, with 181mm crank pulley. Since LET pulleys are non-dampened as soon I replaced the OEM I could feel the slight engine vibration. Also with LET pulley I feel if I push it hard, it feels like the belt slips a little.
Does anyone have any idea if non-dampened pulleys have any negative effect on our engines? Since AMG designed it with dampened. Thoughts?
Does anyone have any idea if non-dampened pulleys have any negative effect on our engines? Since AMG designed it with dampened. Thoughts?
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From: Philadelphia, PA
2008 A8L, 2002 996TT X50, 2009 X5
I have LET Stage I, with 181mm crank pulley. Since LET pulleys are non-dampened as soon I replaced the OEM I could feel the slight engine vibration. Also with LET pulley I feel if I push it hard, it feels like the belt slips a little.
Does anyone have any idea if non-dampened pulleys have any negative effect on our engines? Since AMG designed it with dampened. Thoughts?
Does anyone have any idea if non-dampened pulleys have any negative effect on our engines? Since AMG designed it with dampened. Thoughts?
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From: STL
W203 C230SS
i'm not sure about LET or Evo- but this topic is one of those in which you are going to have two sides that will never come to an agreement. google it- you'll find loads of opinions, test, etc, etc, etc- all trying to backup their opinions.
the only bit of knowledge i can shed is that i have an Esslinger pulley on my 2000 Focus. that pulley was put on somewhere around the 5,000 mile mark. the car, which is now my daily driver, has over 150k miles and is running like a champ. around the 7k mile mark i did a boatload of mods- including Crane stage 2 cams, stiffer springs, and nitrous. to say i've abused that engine is an understatment. aside from a tune up at 100k, i did the timing belt/water pump at 125k- the cams still looked perfect- no wear to speak of on the lobes. i have never had a single problem with the car. the Esslinger pulley is not a dampened unit. so- judging by my particular car- i would say it's not needed. granted- it might be the difference between the engine lasting 300k miles or 400k miles- but who keeps it that long? there would be other failures before that. my opinion is that the mercedes engine would be balanced far better than that of a Ford Focus, therefore the dampened pulley would be even less of an issue.
again, like i said, there are opinions on both sides of the fence- take mine for what you will.
Last edited by bumpnzx3; Sep 30, 2008 at 04:30 PM.
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From: STL
W203 C230SS
i understand the concept of mechanically balanced. but what does mechanically dampened mean? "mechanically" to me means moveable parts. i thought the dampening in a pulley would be rubber, or some sort of viscoelastic material to absorb the vibrations.
Thread Starter
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From: Minneapolis MN
'03 C32 LET Stage I
I myself don't understand the meaning of "mechanically dampened". With no rubber in between, I assumed it was not dampened. Also I can clearly feel the difference between OEM and LET "mechanically dampened" pulleys, may be its just me.
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LET C32 2002
Here is a members' quote "According to LET, the pulley is fluid dampened (A dampening technology used in aircraft applications). Unlike the original MB pulley which is dampened by a Polyurethane Dampener which requires replacements from time to time. this pulley is more durable."
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From: Maine
Not an AMG :(
Those LET pulleys look to be extremely well made so if you are noticing a vibration then you may have a bad install. That's bad news no matter what pulley you are using (OE or otherwise).
Turn your engine on and pop the hood. Check the crank pulley for excess wobble / play. If you are unsure, take some video and post it here and we can give you some idea of whether it is normal or not.
Last edited by boohooramblers; Sep 30, 2008 at 05:36 PM.
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From: STL
W203 C230SS
http://www.fluidampr.com/
how could i have forgotten about that brand/style. that's the same thing i used (possibly from the same build house) on my stroked small block i built for the drag truck. not what i call "mechanical"- but still dampened none the less.
how could i have forgotten about that brand/style. that's the same thing i used (possibly from the same build house) on my stroked small block i built for the drag truck. not what i call "mechanical"- but still dampened none the less.
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From: Philadelphia, PA
2008 A8L, 2002 996TT X50, 2009 X5
Here is a members' quote "According to LET, the pulley is fluid dampened (A dampening technology used in aircraft applications). Unlike the original MB pulley which is dampened by a Polyurethane Dampener which requires replacements from time to time. this pulley is more durable."
As for "what is mechanically-dampened" - ever heard of a spring?
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From: Orange County, CA
GMC - Miata - Trek - P-Car
It’ll likely behoove you to have yours inspected by a competent technician post-haste, if for no other reason than to forestall potentially costly repairs. A correctly installed and properly functioning pulley does not result in untoward vibrations.
Two schools of thought regarding dampened crank pulleys on AMG engines,
both from the same respected member: #1 & #2
From another aftermarket tuner, Dinan.
MB’s service information for your technician, if he doesn’t already have it –
Installation torque:
Permissible runout:
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From: San Diego
ML430, Mini Cooper S and Porsche 911 Twin Turbo
Apologies but I have to correct this mis-conception....
Thus the mass and dampener material are critical to crank life and are tuned for a specific purpose.
Of course the pulley itself has to be mechanically balanced - but it's balancing has nothing to do with balancing out other rotating parts within the engine.
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LET C32 2002
I believe this to be incorrect. The first iteration of LET pullies (aka prototypes and maybe a couple others) were fluid-dampened. The design was then changed to a superior mechanically-dampened design - which I believe is what 99% of LET customers have on their cars. Also, IIRC, it is similar in execution to the evosport dampened pulley - however they probably each have some of their own proprietary design modifications/parameters engineered in, IDK.
As for "what is mechanically-dampened" - ever heard of a spring?
As for "what is mechanically-dampened" - ever heard of a spring?
