[s-cars] belt tensioner

[Tom Green]

Ben,

The  pulley has a plastic protective cover over the center section  
that pops off, revealing the torqx head machine screw that attaches  
the pulley.  It is a two piece pulley secured by 3 rivets encasing the  
bearing.  Drill the heads off the rivets (carefully, the rivets are  
5mm diameter, so a drill bit smaller than 3/16) to remove, then split  
the pulley to remove the bearing (again, carefully so you do not  
distort the stamped metal pulley).

Mine was marked NTN 6203LH on the protective cover and NTN GERMANY  
6203V190 on the outer race.  Previous discussions on this list convinced
me that I could not source this bearing here or from Germany.  The  
bearing size is simple;  6203 is a standard bearing size, easy to  
obtain locally, but the
190  designation is reported to be a temperature rating.  The other  
specification to look for is grade which may not be obvious but  
contained in the class the bearing is listed in.  This affects the rpm  
capability of the bearing, which must approach 10K rpm.

Dave Forgie has kindly provided the FAQ link for Fred's account of his  
repair, and his bearing search.  His choice can be sourced from <www.bdi-usa.com 
 > which has a location just a couple of miles from me.  I sourced  
mine from another local bearing supplier for an RBI bearing 6203RS  
which is specified for 250F, made in China by supposedly US owned and  
supervised plant certified to ISO 9001, yadda, yadda.  You may want  
different sources.  The 5mm rivets aren't readily available, so I  
bought a pound of 5/16 X 3/8 steel rivets from McMaster-Carr (that's  
about 200) which is the closest fit.  They expand when bucked to fill  
the hole, and if you can buck it properly, it will produce a nice  
mushroom head on that end.  I put  the manufactured head on the side  
with the cap retainer, all without clearance issues.  I liked this  
solution better than worrying about bolts and nuts and clearances.

One note, prices have changed since Fred did his repair, and the SNR  
spec bearing lists for over $30.  That's the range supercharger  
bearings sell for, and
prompted me to look around.  His choice was a good one since his  
repair is 4 years old now;  mine was $6 and has been in service for <  
2 years.

I also thoroughly cleaned the spring area, treated the rust, and  
lubricated it through the small openings.  I put a little high  
temperature grease in the openings every spring in the hopes of  
preventing any rust.  That, and keeping the bolts tight so the  
tensioner stays aligned with the belt and operates smoothly are key to  
tensioner longevity.

Tom

On Dec 1, 2008, at 9:57 AM, Ben Swann wrote:

>
> Tom,
>
> I'm sure I'm not the only one who would like a how to on replacing  
> that tenbsioner bearing.  Where you got the bearing and a brief on  
> what was done to replace the bearing would be appreciated.
>
> Ben
>
> [Date: Sun, 30 Nov 2008 17:06:52 -0500
> From: Tom Green <trgreen at comcast.net>
> Subject: Re: [s-cars] belt tensioner
> To: Scar <s-car-list at audifans.com>, Jerry Scott
>         <jerryscott at wispertel.net>
> Message-ID: <D21DE51D-8FF6-406B-B559-A557EAED532D at comcast.net>
> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
>
> http://www.genuinevwaudiparts.com/partlocator/index.cfm?action=searchCatalogOEM&siteid=214407
>
> Getting right to the point, Jerry, that is about the best I think you
> can do, although $185 isn't very good, especially when the part for  
> other models is about  $50 to $75.
>
> If the tension spring is still good in yours, I replaced the pulley  
> bearing in mine.
>
> Tom
>
> On Nov 30, 2008, at 3:00 PM, s-car-list-request at audifans.com wrote:
> > Date: Sun, 30 Nov 2008 09:57:18 -0700
> > From: "Jerry Scott" <jerryscott at wispertel.net>
> > Subject: [s-cars] belt tensioner
> > To: "s-car list" <s-car-list at audifans.com>
> > Message-ID: <1D159CBCCB054DAFA18D38DC1316AEB2 at Jerry5976>
> > Content-Type: text/plain;     charset="iso-8859-1"
> >
> > I need a source for a OE serp. belt tensioner for my 93.  Who has
> > the best prices?
> > Jerry]
>