Date:         Wed, 3 Jun 2015 14:45:39 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: Rear axle torque specs?
Comments: To: Phil Zimmerman <philzimm1@SHAW.CA>
In-Reply-To:  <E0B6D439-B29B-4B18-9750-90C0DEBF82F2@shaw.ca>
Content-Type: text/plain; charset="iso-8859-1"; format=flowed

At 12:21 PM 6/2/2015, Phil Zimmerman wrote:
>When the rear axle nut is torqued to spec and 
>all parts from the hub and stub-axle through the wheel-bearing-housing
>and internal bearing parts are put under this 
>considerable load… if this aint a pre-load; I dunno Ed, 360 ft lbs is sure
>more than sung and significantly greater than 
>finger-tight? (excuse my sarcasm and hyperbole) I would prefer to use
>a few choice swear-words here but, the Vanagon 
>nannies forbid such language.  Forgive my digression here.
>
>Back to deducing or ferreting out a meaning from Ed's confusion..
>What was the question again Ed?

Hi Phil,

I have to stand with Ed on "pre-load" here -- 
it's a thrust load placed on a bearing in advance 
of operating loads.  The way that you're looking 
at it, every single fastener in the van would be 
equally appropriately said to be pre-loaded, 
which makes the term meaningless.  It is 
specifically a thrust load exerted through the 
bearing surfaces, not the tensile/compressile 
force mutually exerted on a fastener and the 
things it fastens.  Blurring this distinction is 
no service to anyone, especially in that bearing 
pre-load is often (usually?) imposed in a manner 
similar to how this axle is assembled, by 
tightening a nut that clamps the assembly.  The 
difference is only in the path through which the 
forces propagate, both halves of the bearing(s)  vs one half.

Yours,
David