boostit

I recently replaced on my 1993 S4 the accessory belt tensioner bearing and accessory belt commonly known as the serpentine belt. The bearing had become worn and noisy. I suspect the belt was also contributing to the racket emanating from the engine bay too.

Fred Munro has a DYI write up on replacing just the accessory belt tensioner bearing by a fairly involved surgical procedure and saving $300+ from a dealer only part by not replacing the entire tensioner assembly. I looked at that but being stubborn and not feeling comfortable with that procedure decided to try another route.

I had found a few websites that listed my car and a new German made Dayco accessory belt tensioner for $80.58. I had looked at the cost of the 6203 bearings Fred was using and the cost difference wasn’t that much plus I thought I’d just return the part if it didn’t work so I ordered one.

I got the part and sure enough it didn’t look anywhere near like the part installed but the pulley / bearing assembly looked really close. I popped the dust cap off the new idler pulley assembly and there staring back at me was a NTN 6203 LHA bearing. This is the exact same bearing that is used on the brand new dealer only part that is Europe sourced only.

I decided to try out my theory and removed the installed accessory belt tensioner and serpentine belt. Compared the old and new pulleys which were identical and so were the bearings. I used a torx# 40 to unscrew the old idler pulley/bearing. After cleaning up the assembly popped on the new idler pulley/bearing assembly and screwed it back on. Just like brand new! Installed a new serpentine belt and rebuilt accessory belt tensioner and fired that baby up. No more squeaks and noise! It worked like a charm and was so easy to do I thought others might like this handy little tidbit.

As an aside I had to cut a 6mm allen wrench to fit the tight space to unloosen the tensioner assembly allen head bolts. You’ll need a 17mm open ended wrench to swing the tensioner assembly off the belt and finally a bolt to shove through the hole to keep the assembly sprung open. Once you do this you’ll never mind doing it again if you have to. It was really pretty painless and worked like a charm.



Audi accessory belt tensioner - Dealer only part, P/N 054 903 133A $300+

Dayco accessory belt tensioner, German made, P/N DY89336 $80.58
(the only part used is the idler pulley/bearing assembly, the rest is a paper weight)

Pulley number markings, PA 66 GF 30 & 462280

Bearing inside idler pulley, P/N NTN 6203 LHA

CRP-Contitech Accessory belt (serpentine belt) PN 054 903 133A $17.95

UrS4boy

Sorry to rain on your parade but that "Euro only" NLA bearing (or better) can be found almost anywhere in North America at a good bearing shop for under $10. For example, a NAPA SKF bearing 6203-2RSJ which is an alternator bearing (should be up to the same heat characteristics as the NLA bearing)is around $10. I bought one for about $7.50 and sourced actual NLA bearings for under $7.

Info about the serpentine belt tensioner and its roller bearing options is available HERE

scarman

In this case, Boostit received a new pulley with the bearing already installed, so he did not have to find any rivets or bolts to reassemble the pulley. He also got a new center bolt and dust cover that I doubt you can source anywhere else. I wouldn't pay $80 for them, but it is nice to have some for replacement if needed.

UrS4boy

All true but, to me, he paid $80 for a bearing worth under $10, notwithstanding the extra work to remove the OE bearing and bolt in a new one. But hey...

scarman

Or, maybe UrS4Boy has one available with new bearing for a lot less than $80. I don't know how much less, but hey..... : > )

UrS4boy

I just didn't want everyone to think that the $80 solution was the only solution.

scarman

Good point. Many owners aren't capable of doing that minor job so some help might be appreciated. They should also know that Miramar Audi sells online as genuinevwaudiparts.com and discounts the tensioner to $223.20.

boostit

I did find Fred Munro's post on the idler pulley surgical procedure and thought about it. But, for $80 I got a whole new idler pulley with bearing from the manufacturer and according to Fred's writeup is the Euro only original bearing. I'm sure there is a direct sub in the US but compared to the thousands I've spent on this car it was dirt cheap. I did like your post though and the link you posted was excellent. Thanks for that.