Question on Bearing change out

[Mike Hester]

Yep. Last year I had a stainless bearing let go in an OS 140RX. It took out the piston, ring, sleeve, and beat the crap out of the pump and the area around the rear bearing. It looked like a hand grenade went off in there.

So, I leave the covers on lately. Might have just been a bad bearing, not sure....but it made a mess and I don't want to go through that again.

-Mike
  ----- Original Message ----- 
  From: Bob Richards 
  To: discussion at nsrca.org 
  Sent: Monday, February 21, 2005 1:28 PM
  Subject: Re: Question on Bearing change out


  I had heard that the "shields" were really dust covers, and would not impede the lubrication from getting to the bearings during normal use. IMHO, in the event of a bearing failure, having the shields in place might prevent parts of the bearing from damaging the rest of the engine. 

  Having said that, I have never installed shielded bearings, so I don't have any experience with my theory. Any comments?

  Bob R.


  Tom Simes <nsrca at shinymetalass.com> wrote:
    On Sun, 20 Feb 2005 11:42:17 -0900
    "Michael Laggis" wrote:

    > Thanks Dave, Bob. After I asked the question I went to
    > bocabearing.com and they said basically do them like the factory. 
    > Thanks for your input. 
    > 
    > Michael Laggis
    > AKA Moose Boy
    > NSRCA 3618 
    > http://www.alaskarc.org

    When I did my first set of bearings, I took a close look at edges of the
    shield material and thought it looked too thick to be pierced with an
    awl and removed per Boca's instructions. I was pretty worried about
    damaging the bearings or races but in the end I sharpened the awl to a
    fine point, took a deep breath and it worked like a charm. I didn't try
    to measure it afterwards, but I believe the shields may be thicker on
    the retaining edge than in the area actually covering the bearings. By
    the way, I'm running Boca's stainless rears with both shields removed
    and leak stop stainless fronts with both seals intact.

    Which reminds me - I need to get an order off for the combat plane and
    my ST .75...

    At the time I suggested to Boca that a few pictures of the procedure
    would definately ease the pucker factor the first time folks do this.


    -- 
    Tom

    _____________________________________________________________________

    | , | Tom Simes
    ---------(@)--------- AMA 230068
    --|-- NSRCA 3830
    ' nsrca at shinymetalass.com
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