This is intended for C4 AAN UrS4/S6 :
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One of our local multiple UrS6 owners (Goran D.) recently purchased a Volvo 272136 serpentine belt pulley based on info I gave him which I got from various posts here on the forum (references at the bottom of this post). He wanted me to compare OE pulleys to his new Volvo pulley and invited me to his shop to document the differences and the similarities. I went over with my disassembled 054903133A serpentine belt tensioner and new SKF 6203-2RSJ bearing ($6 at a local FLAPS (Lordco for the locals)).
The reason he got the Volvo pulley was last year he bought one of the last 054903133A OE serpentine belt tensioners for big bucks from Audi. Unfortunately, he didn't realize it until some time had passed that the new pulley on the new 054903133A belt tensioner pulley was distorted (probably during the factory assembly) and had significant run out. It caused the serpentine belt to chatter and make significant noise. Audi wouldn't replace the assembly (none in stock, NLA now) or give him his money back. Nice
Okay this is what we laid out on the bench to start the comparison

The new OE tensioner pulley and the Volvo 272136 pulley are very similar. Probably made by the same company. The diameters are the same (76 mm) and the bearings are the same, i.e. NTN 6203 LHA. The only differences is the OE pulley is 24 mm wide and the Volvo pulley is 26 mm. Since the 054903137B AAN serpentine belt is 21.36 mm wide, both pulleys are more than wide enough. The extra 1 mm from the centerline of the wider Volvo pulley doesn't actually touch the serpentine belt tensioner body but it does come very close. Too close for Goran. He is going to machine off the extra 1 mm on both edges (he has access to a metal lathe).
This photo shows the two pulleys and their dust caps. The Volvo dust cap is metal and is held on by the Torx-head bolt (new - suppled with the 272136 bearing).



Maintenance:
Goran wanted to show me how the action of the new OE tensioner worked compared to his old one. He put the tensioners in a large vise horizontally, one by one, and then moved the tensioner with a large crescent wrench on the tensioner lug. He had me try too. The new one was very smooth and his old one was almost the same, just a tiny bit of drag. He told me that initially his old one had a very notchy (not smooth) action and that he had improved it by using his compressed air lance to blow crud out of the spring casing and then lubricating the assembly with non-graphite lock lubricant. He demo'd the cleaning on the spare assembly that I brought and just blowing the crud out definitely improved things a bit. He didn't have the lubricant he used in the shop so we couldn't finish the maintenance today. Something to remember to do though, to keep the tensioner moving freely, keeping the proper tension on the serpentine belt.
Thanks to Goran for getting me involved and documenting the Volvo pulley a bit more.
Extras:
Here is the SKF 6203-2RSJ bearing that I bought ($6) to repair the spare tensioner using Fred Munro's DIY (HERE)

Photo courtesy of Sean D. (quattro20v)
quattron8-JC's post about the narrower (21.3 mm wide) 1.8T tensioner pulleys (HERE)
Link to the MEYLE Germany Belt Tensioner Pulley 1009030001 flagged by quattron8-JC:
(HERE)

The Volvo tensioner pulley post by rew (HERE)

Photo courtesy of rew
Pelican Parts search on 272136 (HERE)


Photo courtesy of Pelican Parts
Here is a cross-over listing that I just found:

And finally the Serpentine belt tensioner info post from the Engine Bay Device Map in the FAQ (which I will have to update with a link to this post):
Serpentine Belt Info, importance, PNs and R&R procedure:
***************************
One of our local multiple UrS6 owners (Goran D.) recently purchased a Volvo 272136 serpentine belt pulley based on info I gave him which I got from various posts here on the forum (references at the bottom of this post). He wanted me to compare OE pulleys to his new Volvo pulley and invited me to his shop to document the differences and the similarities. I went over with my disassembled 054903133A serpentine belt tensioner and new SKF 6203-2RSJ bearing ($6 at a local FLAPS (Lordco for the locals)).
The reason he got the Volvo pulley was last year he bought one of the last 054903133A OE serpentine belt tensioners for big bucks from Audi. Unfortunately, he didn't realize it until some time had passed that the new pulley on the new 054903133A belt tensioner pulley was distorted (probably during the factory assembly) and had significant run out. It caused the serpentine belt to chatter and make significant noise. Audi wouldn't replace the assembly (none in stock, NLA now) or give him his money back. Nice

Okay this is what we laid out on the bench to start the comparison

The new OE tensioner pulley and the Volvo 272136 pulley are very similar. Probably made by the same company. The diameters are the same (76 mm) and the bearings are the same, i.e. NTN 6203 LHA. The only differences is the OE pulley is 24 mm wide and the Volvo pulley is 26 mm. Since the 054903137B AAN serpentine belt is 21.36 mm wide, both pulleys are more than wide enough. The extra 1 mm from the centerline of the wider Volvo pulley doesn't actually touch the serpentine belt tensioner body but it does come very close. Too close for Goran. He is going to machine off the extra 1 mm on both edges (he has access to a metal lathe).
This photo shows the two pulleys and their dust caps. The Volvo dust cap is metal and is held on by the Torx-head bolt (new - suppled with the 272136 bearing).



Maintenance:
Goran wanted to show me how the action of the new OE tensioner worked compared to his old one. He put the tensioners in a large vise horizontally, one by one, and then moved the tensioner with a large crescent wrench on the tensioner lug. He had me try too. The new one was very smooth and his old one was almost the same, just a tiny bit of drag. He told me that initially his old one had a very notchy (not smooth) action and that he had improved it by using his compressed air lance to blow crud out of the spring casing and then lubricating the assembly with non-graphite lock lubricant. He demo'd the cleaning on the spare assembly that I brought and just blowing the crud out definitely improved things a bit. He didn't have the lubricant he used in the shop so we couldn't finish the maintenance today. Something to remember to do though, to keep the tensioner moving freely, keeping the proper tension on the serpentine belt.
Thanks to Goran for getting me involved and documenting the Volvo pulley a bit more.
Extras:
Here is the SKF 6203-2RSJ bearing that I bought ($6) to repair the spare tensioner using Fred Munro's DIY (HERE)

Photo courtesy of Sean D. (quattro20v)
quattron8-JC's post about the narrower (21.3 mm wide) 1.8T tensioner pulleys (HERE)
Link to the MEYLE Germany Belt Tensioner Pulley 1009030001 flagged by quattron8-JC:
(HERE)

The Volvo tensioner pulley post by rew (HERE)

Photo courtesy of rew
Pelican Parts search on 272136 (HERE)


Photo courtesy of Pelican Parts
Here is a cross-over listing that I just found:

And finally the Serpentine belt tensioner info post from the Engine Bay Device Map in the FAQ (which I will have to update with a link to this post):
Serpentine Belt Info, importance, PNs and R&R procedure:
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