Replaced C32 Tensioner Pulley
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Super Member
Joined: Aug 2006
Posts: 510
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From: san jose, ca
2002 C32 1987 190E 2.3 334K miles and going
Replaced C32 Tensioner Pulley
The guide pulley and the tensioner pulley are exactly the same but Stealership will not sell you just the tensioner pulley without the spring housing and the same goes if you searched for the whole assembly online.
Pulley alone cost about $70...the whole assembly about $380. Just simply remove the tensioner pulley (clockwise) using a 15mm hex and replace. DONE. You just saved $300 in parts. 30-45 min. job removing and installing
assuming you have replacement part in hand.
Pulley alone cost about $70...the whole assembly about $380. Just simply remove the tensioner pulley (clockwise) using a 15mm hex and replace. DONE. You just saved $300 in parts. 30-45 min. job removing and installing
assuming you have replacement part in hand.
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From: Chicago
E63 SL55 996TT C5Z06
60n5pt1 - was your tensioner pulley wobbling similar to mine as you see in the youtube video i made here? i dont know how to determine if the fix is to replace the pulley or the spring, or just buy the entire tensioner assembly (which is about $300 and i hate to do if only need the pulley or spring to fix the wobble).
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From: Chicago
E63 SL55 996TT C5Z06
I installed a new MB OEM replacement which is the recommended part for a C32 from FCP Euro (new belt tensioner part # A1122001070, old part #A1122000770) and it is identical which you can see from the attached pics.
I got the new belt tensioner bolted on after removing the old one and have the belt lined up properly to then release the tension off the belt tensioner, BUT that is where I am having an problem!!!!!
***For some reason the new belt tensioner will NOT release as i pull on it with a 10 torx socket and socket wrench...anyone ever deal with this???
So cannot remove the pre-existing pin that was already in the new belt tensioner when it shipped and cannot put the belt back on the new tensioner since I cannot release the tension on the new belt tensioner.
attached pics if its helpful to you
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E63 SL55 996TT C5Z06
Could a new tensioner be that strong? to release the tension on my old one it was super easy, but of course that old one was shot and 10 years old.
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Mercedes
Sorry i wasnt clear... but YES the new tensioner I got bolted on fine but when i put the socket wrench back on and try to swing or release tension to slip the belt back on it will NOT budge????
Could a new tensioner be that strong? to release the tension on my old one it was super easy, but of course that old one was shot and 10 years old.
Could a new tensioner be that strong? to release the tension on my old one it was super easy, but of course that old one was shot and 10 years old.
--Kyle
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C32 amg
There is a pin holding it in place u have to take that out to release tension, I can see the pin in the pics pull pin out after its installed then use socket to pull it so u can put in belt, I would put new belt on too
Last edited by Morphh; Jan 28, 2016 at 05:05 PM.
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From: Austin, TX
2006 E55, 2012 GLK350 & 1992 190e sportline
So cannot remove the pre-existing pin that was already in the new belt tensioner when it shipped and cannot put the belt back on the new tensioner since I cannot release the tension on the new belt tensioner.
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From: Chicago
E63 SL55 996TT C5Z06
i bought one of these "serpentine belt tool" wrench which is like 2 feet long plus has an additional extension so gives you plenty of leverage vs my 8" socket wrench, so could could easily release the tensioner with one hand and then reach down to pull that retaining pin out of the tensioner pulley. the tensioner doesnt move or vibrate at all any more and there seems to be better response on the throttle perhaps because the tensioner is new and tight and the belt grips better (??) thanks all for the help on this.
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Joined: Aug 2014
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C32 amg
Insame1 - so i figured it out. newbie as i've never replaced a belt tensioner before.
i bought one of these "serpentine belt tool" wrench which is like 2 feet long plus has an additional extension so gives you plenty of leverage vs my 8" socket wrench, so could could easily release the tensioner with one hand and then reach down to pull that retaining pin out of the tensioner pulley. the tensioner doesnt move or vibrate at all any more and there seems to be better response on the throttle perhaps because the tensioner is new and tight and the belt grips better (??) thanks all for the help on this.
Mercedes C32 AMG tensioner pulley wobble - YouTube
Amazon.com: Powerbuilt 648451 Serpentine Belt Tool Kit: Automotive
i bought one of these "serpentine belt tool" wrench which is like 2 feet long plus has an additional extension so gives you plenty of leverage vs my 8" socket wrench, so could could easily release the tensioner with one hand and then reach down to pull that retaining pin out of the tensioner pulley. the tensioner doesnt move or vibrate at all any more and there seems to be better response on the throttle perhaps because the tensioner is new and tight and the belt grips better (??) thanks all for the help on this.
Mercedes C32 AMG tensioner pulley wobble - YouTube
Amazon.com: Powerbuilt 648451 Serpentine Belt Tool Kit: Automotive
Glad it's working now
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Joined: May 2010
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From: Chicago
E63 SL55 996TT C5Z06
Finally got my new tensioner installed and can notice a better response perhaps because the belt is tighter due to stronger tension. Heres video of the OLD and NEW tensioner...the wobble and slack in the belt is gone!
C32 AMG belt tensioner OLD and bad wobble
C32 AMG belt tensioner NEW and no wobble
This repair is pretty easy. I tried doing this with a small socket wrench but could not get enough leverage on the tensioner torx bolt to release the tension and get the retaining pin in and out. I bought a 2ft long extension wrench (or "serpentine belt tool") to get proper leverage and easily could release tensioner pressure with one hand and then slide the belt on or off with the other hand...
C32 AMG belt tensioner OLD and bad wobble
C32 AMG belt tensioner NEW and no wobble
This repair is pretty easy. I tried doing this with a small socket wrench but could not get enough leverage on the tensioner torx bolt to release the tension and get the retaining pin in and out. I bought a 2ft long extension wrench (or "serpentine belt tool") to get proper leverage and easily could release tensioner pressure with one hand and then slide the belt on or off with the other hand...
Junior Member
Joined: Nov 2015
Posts: 42
Likes: 3
From: Los Angeles, CA
2004 C32 AMG
The guide pulley and the tensioner pulley are exactly the same but Stealership will not sell you just the tensioner pulley without the spring housing and the same goes if you searched for the whole assembly online.
Pulley alone cost about $70...the whole assembly about $380. Just simply remove the tensioner pulley (clockwise) using a 15mm hex and replace. DONE. You just saved $300 in parts. 30-45 min. job removing and installing
assuming you have replacement part in hand.
Pulley alone cost about $70...the whole assembly about $380. Just simply remove the tensioner pulley (clockwise) using a 15mm hex and replace. DONE. You just saved $300 in parts. 30-45 min. job removing and installing
assuming you have replacement part in hand.
Super Member
Joined: Aug 2014
Posts: 636
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C32 amg
email rob @ needswing, I forget but he would know or it might be on his website
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From: Chicago
E63 SL55 996TT C5Z06
purplecat001 - 
embarrassed to admit but i didnt find a torque spec for the bolts on the belt tensioner when i installed the new one. i didnt over tighten, but definitely eased it up pretty tight and no issues a year later.
let me ask the guy who's doing my engine swap (i'm down a piston in current original motor) if he knows the belt tensioner torque spec and i'll come back here shortly.... stay tuned
embarrassed to admit but i didnt find a torque spec for the bolts on the belt tensioner when i installed the new one. i didnt over tighten, but definitely eased it up pretty tight and no issues a year later. let me ask the guy who's doing my engine swap (i'm down a piston in current original motor) if he knows the belt tensioner torque spec and i'll come back here shortly.... stay tuned
Junior Member
Joined: Nov 2015
Posts: 42
Likes: 3
From: Los Angeles, CA
2004 C32 AMG
purplecat001 - embarrassed to admit but i didnt find a torque spec for the bolts on the belt tensioner when i installed the new one. i didnt over tighten, but definitely eased it up pretty tight and no issues a year later.
let me ask the guy who's doing my engine swap (i'm down a piston in current original motor) if he knows the belt tensioner torque spec and i'll come back here shortly.... stay tuned
embarrassed to admit but i didnt find a torque spec for the bolts on the belt tensioner when i installed the new one. i didnt over tighten, but definitely eased it up pretty tight and no issues a year later. let me ask the guy who's doing my engine swap (i'm down a piston in current original motor) if he knows the belt tensioner torque spec and i'll come back here shortly.... stay tuned
Junior Member
Joined: Nov 2015
Posts: 42
Likes: 3
From: Los Angeles, CA
2004 C32 AMG
Last night, I was digging through the MB repair software and found the attached PDFs. The OP was absolutely correct - the tensioner pulley part number is the same as the stock lower guide pulley. Based off of the diagram, (I think) it is stating 25nm for the pulley screw. If I am misreading it, please let me know.
I included the PDFs for other C32 owners looking to take on any of this repair with the tensioner.
I included the PDFs for other C32 owners looking to take on any of this repair with the tensioner.
