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Cam drive Pulley bearings

Discussion in '308/328' started by Saabguy, Aug 6, 2018.

  1. Saabguy

    Saabguy Formula 3
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    Mar 28, 2012
    1,176
    Shreveport, LA
    Hello all, I have been trying to determine the number for the cam drive pulley outer bearing. Research through several older threads indicates that one can go with the bearings from the official suppliers or that the same bearing can be purchased at one fifth the price if you know the bearing number. And that number varies depending on who has most recently done the work.

    My question is simple; What is the bearing number and spec (C3 or C4) to purchase at my local bearing shop?

    Thanks all!
     
  2. 4right

    4right Formula 3
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    I am all for saving money, however, this wouldn't be an area that I would try to save money at. The cost of the correct bearing is insignificant in comparison to the value of your engine. But that's just me.
     
  3. lm2504me

    lm2504me Formula Junior
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    Aug 26, 2004
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    Richard
  4. thorn

    thorn Formula 3
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    Aug 7, 2012
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    It appears to me that SKF 630647 is the correct part, but I haven't quickly found a ton of suppliers for it. SKF gets counterfeited quite a bit too, so be wary of that.
     
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  5. Ferraripilot

    Ferraripilot F1 World Champ
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    May 10, 2006
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    It's man
    Some years used sealed bearings too, so be mindful to use what is correct for your year. Be sure to use the best quality bearing there and seal with a double lip nitrile or Viton seal. . The design in general makes for a very difficult removal process with the engine in, but it can be done!
     
  6. kcabpilot

    kcabpilot Formula Junior

    Apr 17, 2014
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    Paul
    I've been researching this as well and talked to MSC who contacted SKF and the end result is that 630647 is not an SKF number. Prior to calling SKF MSC did come up with a bearing using that number and it was 17x44x14 but not SKF so I don't know what it is. On Ricambi America the Ferrari part number is 121274 and if you zoom on the picture they have you can see the SKF etching on the outer race rim but can't make out the number. Ricambi's price is $143 ea. Same or similar prices with the other usual vendors so I just ordered from Ferrari Parts Exchange since they are just up the road from me. When I get them tomorrow or Wednesday, if they are SKF, I'll post the numbers.
     
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  7. Saabguy

    Saabguy Formula 3
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    Mar 28, 2012
    1,176
    Shreveport, LA
    And that thread is why I started mine. It lists two bearings saying that they aren't available followed by alternate specs for the bearing. Top that with the info being over 6 years old and I figure that it's time for new info.

     
  8. kcabpilot

    kcabpilot Formula Junior

    Apr 17, 2014
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    I got my bearings today however, rather than solving the puzzle they seem to just add to it. They are SKF 6303 2RS1 as etched on the outer race edge and they measure 17x44x14. If you Google that part number you come up with a lot of conflicting info. Prices range from $6.99 on eBay to $98.00 on a vendor site and the size listed is 17x47x14.

    So your guess is still as good as mine
     
  9. johnk...

    johnk... F1 Veteran
    Silver Subscribed Owner

    Jun 11, 2004
    6,360
    If
    You check the ebay ones, they are shipped from China. Assume that's where they are made. There are some NOS made in France for about $20 if you trust old seals and old grease.
     
  10. kcabpilot

    kcabpilot Formula Junior

    Apr 17, 2014
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    Paul
    I think I got good ones but I paid for them - $130/ea, money's no good if it's not getting passed around
     
  11. Saabguy

    Saabguy Formula 3
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    Mar 28, 2012
    1,176
    Shreveport, LA
    Did you actually measure these or install them? I would think that a 3mm difference in OD would prevent them from being installed at all.

     
  12. kcabpilot

    kcabpilot Formula Junior

    Apr 17, 2014
    576
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    Paul
    I've measured the new ones but have not pulled my originals out yet to compare. I'm not a bearing expert but if you go to the SKF site specs page for the W 6303-2RS1 bearing it shows an outer diameter of 47 mm on the "Dimensions" figure but below that is another figure showing "Abutment dimensions" and if you add up Da + (ra x 2) you get 44 mm. Where the 47 comes from I don't know, the bearings I have are marked SKF 6303-2RS1 and measure 44 mm with a caliper.

    SKF W 6303-2RS1 spec sheet
     
  13. Saabguy

    Saabguy Formula 3
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    Mar 28, 2012
    1,176
    Shreveport, LA
    I too had checked the spec sheet but I wanted to see what they actually measured, the 'ol Mk I Eyeball. That sounds better, time to search or call. Thanks,

    Lester

     
  14. Saabguy

    Saabguy Formula 3
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    Mar 28, 2012
    1,176
    Shreveport, LA
    So, some things to know. Those use Stainless Steel bearings. There are many of them in Tennessee. They cast the same as if ordered through Superformance et.al.

    YMMV

    Lester
     
  15. kcabpilot

    kcabpilot Formula Junior

    Apr 17, 2014
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    Paul
    Before I can pull and measure the original bearings I need to remove the drive pulleys and before I can do that I need to get a 28 mm ring nut socket. So it will be next week sometime.
     
  16. Saabguy

    Saabguy Formula 3
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    Mar 28, 2012
    1,176
    Shreveport, LA
    I will be waiting with baited breath... and for the temperatures to cool. I already ordered the ring nut socket so I am set to go. Except I don't have the special tool to pull out the bearing. What are your plans?

     
  17. derekw

    derekw Formula Junior
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  18. Saabguy

    Saabguy Formula 3
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    Mar 28, 2012
    1,176
    Shreveport, LA
    I'm not co minced about that. The bearing specified has stainless steel balls (So did I once, sigh) and significantly higher static and dynamic load numbers.Not that I am an engineer but one of them at some time decided that the bearing to have had those numbers so I see no reason to hope that my choice would work over the engineers choice. And besides, I already ordered from Superformance.

     
  19. Saabguy

    Saabguy Formula 3
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    Mar 28, 2012
    1,176
    Shreveport, LA
    Ahem, it should read that I am not convinced... I need much more time to allow for corrections!
     
  20. derekw

    derekw Formula Junior
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    Could you please share the load figures you have? Thanks!
     
  21. derekw

    derekw Formula Junior
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    Sep 7, 2010
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    Thanks, It has been two years since I went through this but from what I recall I went with NTN because of the viton seals and high temp grease. The consensus from the many previous Fchat discussions was that the NBR seals fail due to high temps and the SKF bearings are no longer available with the original HT51 grease and the current ones have HT22 and NBR seals. I'm sure they will work fine-- I tend to be a bit pedantic :)
     
  22. Saabguy

    Saabguy Formula 3
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    Mar 28, 2012
    1,176
    Shreveport, LA
    As I said, I'm no engineer and the local bearing shop wanted $180 per bearing special order. Superformance was less and reputable.

    That's when I stopped looking very hard.

    ;-)

     
  23. Saabguy

    Saabguy Formula 3
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    Mar 28, 2012
    1,176
    Shreveport, LA
    HOLY CRAP BATMAN!

    Ordered bearings from Superformance website over the weekend, on Monday I received confirmation that CC had processed and the bearings arrived today! That's service!
     
  24. kcabpilot

    kcabpilot Formula Junior

    Apr 17, 2014
    576
    California SF area
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    Paul
    What are they? I got my ring nut socket today and pulled my drive sprockets. I haven't pulled my bearings out yet but they are not SKF 6303's The outer diameter is 40 mm. The SKF's are 44 mm.

    So, for me at least, the puzzle just keeps getting deeper.
     

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