Cup car 3 piece BBS wheel repair ...
#1
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Everything about this Cup car is new to me and that includes servicing the 3 piece BBS wheel. My Cup car came with 3 sets of BBS wheels and one rear wheel had a bend outer rim and one front wheel has a slow leak. It was easy to take them apart but ... how do I seal them back up to prevent future leak? Replace the O-ring with rubber seal vs just applying some sort of silicon sealant?
I did bunch of research and looks like alot of folks don't bother to replace the sealing rubber O-ring from BBS since they fail with time and just apply silicon sealant along the exposed seam. Some suggested Dow Corning 832 silicon sealant:
http://www.bdi-usa.com/DidYouKnow/Do...spx?Print=true
![](http://www.bdi-usa.com/FileUploads/CMSFiles/Dow%20Corning%5B0%5D.jpg)
I could not find the replacement BBS sealing O-ring any where. I think it is an exclusive Porsche motorsports parts as shown by #4 on the following diagram
![](http://img718.imageshack.us/img718/623/bbswheeldiagram.jpg)
Here is what the wheels look like. Bend outer rim on the rear wheel and slow leak from the one of the front wheel
![](http://img10.imageshack.us/img10/9238/pict8869.jpg)
The rubber seal on the rear wheel is exposed vs concealed set up for the front wheel
![](http://img64.imageshack.us/img64/9914/pict8870.jpg)
![](http://img841.imageshack.us/img841/8950/pict8871.jpg)
The replacement outer rim for the rear wheel
![](http://img16.imageshack.us/img16/5025/pict8873.jpg)
The 20+ bolts required a 12 points 8 mm socket which was hard to find![Mad](https://rennlist.com/forums/images/smilies/mad.gif)
![](http://img12.imageshack.us/img12/9202/pict8874.jpg)
Here is what the sealing O-ring look like
![](http://img577.imageshack.us/img577/5591/pict8875.jpg)
Everything apart
![](http://img856.imageshack.us/img856/4839/pict8876.jpg)
Anyone has a good suggestion on how to get rid of caked on tire rubber??![EEK!](https://rennlist.com/forums/images/smilies/eek.gif)
I did bunch of research and looks like alot of folks don't bother to replace the sealing rubber O-ring from BBS since they fail with time and just apply silicon sealant along the exposed seam. Some suggested Dow Corning 832 silicon sealant:
http://www.bdi-usa.com/DidYouKnow/Do...spx?Print=true
![](http://www.bdi-usa.com/FileUploads/CMSFiles/Dow%20Corning%5B0%5D.jpg)
I could not find the replacement BBS sealing O-ring any where. I think it is an exclusive Porsche motorsports parts as shown by #4 on the following diagram
![](http://img718.imageshack.us/img718/623/bbswheeldiagram.jpg)
Here is what the wheels look like. Bend outer rim on the rear wheel and slow leak from the one of the front wheel
![](http://img10.imageshack.us/img10/9238/pict8869.jpg)
The rubber seal on the rear wheel is exposed vs concealed set up for the front wheel
![](http://img64.imageshack.us/img64/9914/pict8870.jpg)
![](http://img841.imageshack.us/img841/8950/pict8871.jpg)
The replacement outer rim for the rear wheel
![](http://img16.imageshack.us/img16/5025/pict8873.jpg)
The 20+ bolts required a 12 points 8 mm socket which was hard to find
![Mad](https://rennlist.com/forums/images/smilies/mad.gif)
![](http://img12.imageshack.us/img12/9202/pict8874.jpg)
Here is what the sealing O-ring look like
![](http://img577.imageshack.us/img577/5591/pict8875.jpg)
Everything apart
![](http://img856.imageshack.us/img856/4839/pict8876.jpg)
Anyone has a good suggestion on how to get rid of caked on tire rubber??
![EEK!](https://rennlist.com/forums/images/smilies/eek.gif)
![](http://img830.imageshack.us/img830/2551/pict8878.jpg)
#2
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Don't know about sealant but a new gasket can be bought directly from BBS Motorsports. Would replace the hardware as well, it's cheap insurance. Call Eric N. at BBS 770 967-9574 ext 3028. He can also hook you up on a new outer rim half as well.
#3
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To help prevent leaks in the future torque all bolts to 155 in/lbs. Mount the tire then let the air out and re-torque the bolts as seating the bead will shift the rim halves and you may find a few bolts that are now loose.
#4
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#5
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Just talked to Eric at BBS. Really friendly, helpful guy. The phone number for him is right (770 967 9547) and he says hit 0 and ask for him from the operator rather than call his extension--he is not always at his desk. Great info on Rennlist!
#7
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another o-sh*t I had was one of the bolts breaking off in a magnes wheel. bbs sells the threaded inserts also. they're pressed in there quite tight.
...it's had to tell from pic, does your center have threaded inserts?
...it's had to tell from pic, does your center have threaded inserts?
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#8
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If the wheels are new to you, it would be worth sending them to BBS to have them go through them. I had one come apart during mounting, and it hurt the Michelin tech. It likely would have failed on track. Bolts had been reused before buying the car, and I didn't know it. Eric was great. He replaced all the hardware and seals, and a rim half that was too far out of spec.