[Healeys] Top Trunnion Needle Bearings

[Bob Spidell]

Tom,

I am totally unqualified to answer this question, but that's never 
stopped me ;)

Generally, I have heard--and this makes mucho sense--that needle 
bearings aren't a
particularly good idea on (for lack of a better word) "reciprocating" 
pivots.  Usually, this
is in reference to using needle bearings on valve rockers, but the 
principle is the same:
since the bearing doesn't rotate completely about the shaft, the needle 
bearings are
essentially rocking back and forth on the same limited surfaces (also 
you are
"concentrating" the friction and pressure on less surface area than for 
a bushing).  
Obviously, this can cause excessive localized wear, even to the point of 
wearing
grooves in the shaft or flat-spotting the bearings themselves.

Given that the bushes are (should be) regularly lubed with quality 
grease (I don't think
they're oillite, BTW), I'd expect them to last 100K miles or more.  The 
needle bearings
might make steering a teensy bit easier, but who doesn't need a little 
biceps workout?


bs


Tom Rech wrote:
> I'm thinking about rebuilding my front suspension and using the AH Spares
> needle bearings (I'm assuming they're needle bearings) in place of the
> original oillite washers.  Before I buy, I would like to hear the list's
> opinion.  Are they worth the expense?
>  
> Tom Rech
> 59 BT7
> _______________________________________________
> bspidell at comcast.net 
>
> Healeys at autox.team.net
> http://autox.team.net/mailman/listinfo/healeys
>
>   

-- 
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Bob Spidell         San Jose, CA        bspidell at comcast.net
'67 Austin-Healey 3000             '56 Austin-Healey 100M
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