Date: Wed, 3 Jun 2015 09:08:21 -0700
Reply-To: Alistair Bell <albell@SHAW.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Alistair Bell <albell@SHAW.CA>
Subject: Re: Rear axle torque specs?
In-Reply-To: <vanagon%2015060311535059@GERRY.VANAGON.COM>
Content-Type: text/plain; charset=utf-8
And if you continue to think of the stub axle and castellated nut as a nut and bolt, then look up the torque specs for a M30x1.5 bolt. It's a big bolt, takes a big torque. 360 ft lbs is on the low end of the range.
It's not hard to imagine that the engineers wanted to have the stub axle stretch a little when the castellated nut is tightened to spec. What with the heat cycling, vibration, axle torque I think they wanted the hub to stay on.
Doesn't the Bentley procedure say to tighten nut to spec, then one castellation more to fit cotter pin? Seems to me that 360 ft lbs is what they consider minimum, and you might have to go higher to get the pin in.
Alistair
> On Jun 3, 2015, at 8:53 AM, Ed McLean <email99@BELLSOUTH.NET> wrote:
>
>> On Wed, 3 Jun 2015 08:07:22 -0700, Alistair Bell <albell@SHAW.CA> wrote:
>>
>>
>> The 360 ft lbs of torque is not bearing against the circlip. You could
> assemble the stub axle, hub, and bearings outside the bearing housing.
> The big nut presses the hub against the inner race of the outer bearing,
> which presses against the spacer, which presses against the inner race
> of the inner bearing.
>>
>> In other words, the stub axle is like a big bolt, with the nut on the
> end pressing what ever is between the nut and the head of the bolt.
>>
>
> Thanks, Alistair. That's what I said, but you put it much clearer.
>
>
>
>> The outer bearing has some play in it even when new. I just checked a
> brand new one and I can make the inner race rock slightly.
>>
>
> And that, and to hold the hub solidly on the axle, is why it needs 369
> lbs-ft of torque, or 500 N-m, which is a nice round number that happens
> to be big enough to hold things together but not too big so the nut
> can't be taken off with the proper tool.
>
> This video at 04:53 shows the proper tool to remove and tighten (if you
> gently stand on the pipe at the proper place) the axle nut:
>
> http://campervanculture.com/2011/07/jed-replaces-the-rear-wheel-bearing-
> on-his-t25-vanagon-syncro/
>
>
> Thanks again,
>
> Ed
>
>
>
>> Alistair
>>
>>
>>> On Jun 3, 2015, at 3:09 AM, Frank Condelli <RAlanen@AOL.COM> wrote:
>>>
>>> EXACTLY ! All I can tell you is that from “experience†if
> that spacer is shorter than the spec I mention, the wheel and hub will
> rock back and forth. I “consider†over 1/4†rock excessive and
> therefore recommend replacing the bearings and spacer. HOWEVER, â
> €œsometimes†if the wear has been excessive for a long time the hub end
> will have worn and it too will need to be replaced to make up the
> correct length. NONE of this is indicated in the Bentley, it is from my
> own observations. AND to add more to the confusion, I have NEVER been
> able to understand why the 360 ft. lbs. of torques is needed on that
> axle nut. It’s just compressing the hub, bearing inner races and
> spacer up against the circlip on the axle.
>>>
>>>
>>>> On Jun 2, 2015, at 1:29 PM, Automatic digest processor
> <LISTSERV@GERRY.VANAGON.COM> wrote:
>>>>
>>>> I'm assuming (not always safe to do here) he or others measured new
> OEM =
>>>> Spacers and recorded the measurements.
>>>
>>>
>>>
>>> Cheers,
>>>
>>> Frank Condelli
>>> Almonte, Ontario, Canada
>>> '87 VW Westy, '00 Kawasaki 250 Sherpa, "98 Ducati 750 Monster &
> Lionel Trains (Collection for sale
> <http://frankcondelli.com/trainsal.htm>)
>>> Frank Condelli & Associates <http://www.frankcondelli.com/> -
> Vanagon/Vanagon Westfalia Service in the Ottawa Valley
>>> BusFusion <http://www.busfusion.com/> a VW Camper camping event,
> Almonte, ON, June 04 ~07, 2015
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