Home Forums Tech Talk School me on axle bearings

This topic contains 4 replies, has 4 voices, and was last updated by  Chris Beebe 1 year, 3 months ago.

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  • #8458

    Chris Beebe
    Participant

    I will be changing out my rear brake hub in the next couple of weeks and was thinking of changing the axle bearings while I am in there. I have only had this kart for a few months and after the first couple of track days the bearings were making a lot of noise. Like they were dry inside. I lubed them up and have not had any issues but I dont need any problems later so now I need to order some up. Here is where it gets a little foggy! The three bearings I have are UC208K bearings. Its a shifter kart if that matters any. In my searching I can find endless UC208 bearings but none with the K at the end? Anyone know what I need or what the K means. Looks like the UC208 will work as far as the 40mm X 80mm but how about strength? I dont need the big $$$ stuff but I dont want to pay the money and have a bearing go out after a few races! No cheap stuff if you know what I mean. I guess last thing to add is are there any tricks I need to know about changing out the bearings or is it typical straight forward stuff for someone with a legit mechanical background?

    #8481

    Steen Carstensen
    Participant

    What make is your kart??? I would contact the nearest dealer and order what you need. Here is an example of what you need.

    http://italianmotorsusa.com/collections/bearings/products/40mm-bearing.

    #8635

    Walt Gifford
    Participant

    The K might mean the bearing had a tapered bore at one point then was reworked for a straight bore. Anyway, you want a bearing that’s flat on one side. Check the link.

     

    http://www.bocabearings.com/bearing-inventory/Insert-Bearings/10668/40x80x34-SB20840MM

     

    Make sure you check the width. Just put them on and don’t try to clean and lube them with lighter oil. The factory grease will keep the balls from clutching on the straight and provide the best lube when cornering. The seals will keep the dirt out for years. I use axle collars on both sides of the left bearing and only lightly snug the set screws with some loctite to keep the inner race turning with the axle. That’s it.

    Gif

    #8642

    William Martin
    Participant

    Walt, excellent choice of bearing. Have the NTN equivalent I first installed in 1998 on my current kart…still quiet and tight.

     

    #8650

    Chris Beebe
    Participant

    <div class=”d4p-bbp-quote-title”>Walt Gifford wrote:</div>
    The K might mean the bearing had a tapered bore at one point then was reworked for a straight bore. Anyway, you want a bearing that’s flat on one side. Check the link. http://www.bocabearings.com/bearing-inventory/Insert-Bearings/10668/40x80x34-SB20840MM Make sure you check the width. Just put them on and don’t try to clean and lube them with lighter oil. The factory grease will keep the balls from clutching on the straight and provide the best lube when cornering. The seals will keep the dirt out for years. I use axle collars on both sides of the left bearing and only lightly snug the set screws with some by Text-Enhance” href=”#”>loctite to keep the inner race turning with the axle. That’s it. Gif

    <hr />

    <div class=”bbp-reply-signature”>40 years karting experience
    FAA Jet engine mechanic
    Yamaha KT100 service center</div>
    <div class=”bbp-reply-signature”></div>
    <div class=”bbp-reply-signature”>Good info! I found that the K was for taper but looking at the bearing visually I could not find any taper! I do however have bearings on the axle that are not flush on one side. I think I will keep it this way because it helps with the axle collars to frame clearances! If I ran the flush on one side bearing I would not be able to run the collars! I even talked to a bearing supply house about the K and they were not even sure what it was. They are china bearings so maybe it has something to do with that! :)</div>

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