NEVER tighten your axle nut with an impact driver!
1.) You can never be sure of the exact torque.
2.) You can strip the threads.

ONLY use a proper torque wrench and manually apply the force to tighten
it.  If none is available, use a 3/4" drive 46mm socket and breaker bar
with a cheater pipe that fits over the bar.  Foot/ pounds is calculated
by so many pounds applied at so many feet from the fastener; so my 225
lb. body standing (NOT jumping!) on the spot on a bar  that's 2 feet
from the center of the axle nut will be applying 450 ft/lbs of torque to
the nut.  (or your 150 lb body standing 3 feet out will apply 450
ft/lbs.; so weight X distance = torque applied) , this simple method has
worked for me for over 30 years with no fancy torque wrenches or impact
guns. I've broken many 1/2" drive ratchets and breaker bars doing Beetle
36mm axle nuts to 235 ft/lbs and bought 3/4" drive stuff a couple of
years ago.  Craftsman and Snap-On have always replaced them under
warrantee, even though I kept breaking them for years. Also, NEVER back
off this torque to align the cotter-pin holes, ALWAYS tighten them
further to line it up with the next hole.

You will likely find that it takes a LOT more torque to break them
loose, and you can use an impact driver to loosen them or an axle-nut
beater tool, but some folks think that this damages your axle bearings.
I never had this happen to me, but YMMV.

Mike B.

On 11/15/2012 12:45 PM, Stuart MacMillan wrote:
> Yes, replace all of the parts!   This is what can happen if a rear wheel
> falls off at 65 mph (FF to 1:34): http://www.youtube.com/watch?v=YGKlWqSadlQ
>
>
> Last time I did this job I rented a 3/4 drive electric impact driver and
> bought a socket.
>
> Stuart
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> Jeff Lincoln
> Sent: Thursday, November 15, 2012 6:25 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: loose rear axle nut
>
> John,
>
> Listen to these guys!!!! I recently had to replace my rear wheel bearings -
> when I put everything back together I must not have gotten that nut to the
> proper torque. Everything seemed fine for a while and then I started to hear
> rumbling while on a trip. We were 3 hours from home when I stopped to check
> it and saw that one side of the cotter pin had been sheared off!!!!
> That nut was loose as hell. We got some help and did the best we could and
> litterally limped home.
>
> The bearings I had just put in looked good still but I replaced tyhem anyway
> - along with the hub and stub.
>
> When you go to put that all back together you might think 360 ft lbs is over
> kill but it is not. I wasn't smart enough to figure out the math of my
> weight and how long of a breaker I needed. So I just borrowd a super heavy
> duty torque wrench from a friend. It went up to 450 or 600 ft lbs or
> something like that. I tell you when I got the wrench to 360 it was still a
> way before I hit the next cotter pin slot - I don't remember exactly but I
> was over 380 ft lbs by the time I got to that next slot.
>
> Good luck!
>
>
> --
> Thanks,
>
> Jeff
> '85 GL (Gertie)
> '78 Bus (Melissa) Patty's Bus