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  1. #1

    Pump Bearing 101

    With the introduction of a few new kits that we have out, I thought i would put up a post on some of the info on pump bearings that led up to these new products. I posted some info on someones post about the 05 pump but I thought I'd start a seperate thread.
    First, keep in mind that "all bearings are not created equal" (a quote from one of the bearing mfgs. )
    Second, Remember the FACT that ---a chain is as strong as its weakest link.
    Some of the info here is not new and has been compiled of reasearch over the years and also my desire to always looking to "build a better mousetrap" so to speak.
    Many have never had a pump bearing failure---great! ( many never had a crank bearing failure either ) but owning a shop that probably rebuilds literally in the hundreds every year, I can tell you that they do fail.

    Most of this info will pertain the the new style pumps 2000+ but the basic dynamics pertains to all pumps.
    There are two "loads" at work in your pump RADIAL and AXIAL. Radial being the rotational load on the spinning bearing ( self explanatory ) and Axial being the linear load or the load on the axis ( hence the name ).( this is produced by the thrust from the impeller )
    Ever notice the #'s on the bearing--- theyre more than just a part #.
    Here are the pics of the 2 OEM stock bearings in the GPR style pump.

    front bearing and rear bearing

    The OEM front bearing is a standard duty 6205 bearing. The rear a 6304R "SH" bearing. The "SH" designation is our focus here.
    In the GPR pump, 100% of the AXIAL load ( we talked about this earlier ) is placed on this 6305 rear bearing.
    The OEM Yamaha rear bearing is an EXCELLENT bearing. the "SH" designation means its a heavy duty / long life "hardened" bearing. This was necessary to handle the axial load--- a standard bearing would hardly last in this application.
    While the 6304RSH rear bearing is an excellent bearing, many times it cannot handle it alone even in stock applications let alone the mega power machines and conversions many of you are putting together.
    What I will be focusing here is on the reasearch and solutions on my findings. There are a few ways to improve the durability well above and beyond the stock OEM parts can offer.
    First and the most simple is to upgrade the front 6205 bearing. Remember before that the front bearing is a standard "6205" bearing. We have been including a custom 6205 with the "SH" designation in our pump conversion kits and have decided to offer them in seperate smaller kits.

    Upgrading the front bearing alone, still doesnt address the AXIAL LOAD issue.
    Before I go further I have to give credit where its due. Group K a while ago came up with a bushing that places or "transfers" some of this load to the front bearing. EXCELLENT idea! but this is where a "matter of differences" come into play and im not stating anyone here is right or wrong here. These are MY conclusions from MY research and development.
    Remember my second statement "a chain is as strong as its weakest link"
    Now remember the fact that the 2 oem bearings ARE different. the heavy duty/long life 6304R "SH" rear bearing and the standard duty 6205 front.
    STOP!..... THINK!..... before anyone gets on my case about this one... you come up with the conclusion if these were "connected"...
    Here are the facts on a "SH" bearing vs standard--10X Longer life in contaminated oil, 6X Longer life in clean oil, 8X more dent resistant, and 1.5X the wear resistance.
    Our first upgrade to address the AXIAL LOAD issue was to combine one of our new HEAVY DUTY / LONG LIFE "SH" bearing ( closeup shown above ) with our AXIAL LOAD SUPPORT BUSHING.

    The next step was to come up with an ULTIMATE setup!!!
    We replaced the single row front bearing altogether and went with a DOUBLE ROW MAXIMUM CAPACITY bearing ( doubles the radial and axial support over a single row ) along with our custom spacer and our AXIAL LOAD SUPPORT BUSHING.

    OVERKILL??? Darn right it is!!!
    Last edited by ISLANDRACING; 01-03-2008 at 12:59 PM.

  2. #2
    One day at a time..... N8R's Avatar
    Join Date
    Dec 2005
    how much to upgrade? thanks

  3. #3
    Sorry, forgot to add.
    Will be glad to answer technical related questions reguarding this info here on the forum but any business related questions or questions about our product please keep off the forum and call or email us directly privately---( not Private message )

  4. #4
    dhoad's Avatar
    Join Date
    Aug 2005
    North Aurora, Illinois, United States
    great info Carl!

  5. #5
    cheatin' piston popper addicted's Avatar
    Join Date
    Jul 2006
    north jersey
    That's pretty cool Carl. 1 question though, did you concider an angular contact bearing? I would think that the SH bearing in the front, especially a dbl row, would handle all the radial load, while an angular contact bearing in the rear would do a much better job with the axial load.

    Just thinking out loud here.

  6. #6
    addicted-- done all that homeworkand did look into the angular contact-- the rear yam bearing ( deep groove ) has an excellent radial and axial load rating with the "SH" designation.
    also the way the driveshaft is designed, you cannot place the axial load on only the front bearing.
    The old raider ( similar large front bearing ) had the driveshaft that placed the axial load on solely that front double row bearing notice there was never a nut on the rear

  7. #7
    Dirty Sanchez's Avatar
    Join Date
    Dec 2005
    Northern Virginia
    Nice explanation- Island- lots of good info

  8. #8
    cheatin' piston popper addicted's Avatar
    Join Date
    Jul 2006
    north jersey
    ahh, ok. I figured you looked into it. I was just interested in the rationale.

  9. #9
    ....back from the dead.... J-ME's Avatar
    Join Date
    Aug 2005
    Nice post!

    I like building better mousetraps

  10. #10
    RUNWME's Avatar
    Join Date
    Aug 2007
    Little River, SC

    Great information.... thanks for bringing this product to market


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