Date:         Wed, 16 Jun 2010 16:49:31 -0500
Reply-To:     mcneely4@COX.NET
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Dave Mcneely <mcneely4@COX.NET>
Subject:      seat belt replacement, tough anchor bolts
Content-Type: text/plain; charset=utf-8

For those who might be interested, I finally got my seat belt receiver (female buckle side) anchor bolts (rear seat, '91 VW Vanagon GL Campmobile) properly installed.   Some may remember that these bolts required inordinate force to back out, and then I reinstalled them using force well over the recommended 40-45 lbs ft.  After advice from David Bierl, our esteemed moderator and exceedingly nice and helpful guy, and Lucas of GoWesty, I chased the bore threads with a tap, and fitted new bolts.  One bolt fitted properly after all this, and torqued properly to 40 lbs ft.  The other seemed to tighten down, but would not torque to 40 ft lbs, instead, spinning as if threads might be stripped in the bore.

I considered two possible solutions:  (1) Retapping the bore to the next larger size and installing an oversize bolt, (2) installing a longer bolt, and fitting a washer and nut from the back side.  In both cases, I would torque to the 40 ft. lbs recommended by GoWesty.

I discussed both possibilities with David, with a GoWesty technician, and with my local mechanic.  All three seemed very comfortable with either solution, but the consensus was that the nut and washer might be marginally better, as no material would be removed from a holding nut.

So, by this time being very tired of the job, I turned it over to my local mechanic, who took care of it, installing a longer bolt, and a nut and washer from the back side.  We are comfortable with this solution as being comparable to the original installation in strength.

BTW, following GoWesty's description of the bolts as being 7/16 x 20 (fine thread) rather than a metric bolt, I used that size, readily available locally while 11 mm was very hard to find.  Turns out that, as I suspected and David knew, the original bolts were in fact metric, but so close to the 7/16 x20 as to not matter practically (they fitted perfectly into that sized gauge at the hardware store).  7/16 is trivially larger than the 11 mm original bolt.  I haven't yet, but I will mark the installation so any unsuspecting future owner or mechanic will not be surprised to find the non-standard bolt size and non-standard installation.

thanks to those list members who corrected me earlier concerning my "muscling" of the original bolts.

And, to clarify completely, David certainly did not advise me to overtorque the bolts, if anyone got the impression that he did.  He advised me to clean the bore and bolts before installing them.  When he learned that I had overtorqued the bolts, he advised me to chase the bore threads and to use brand new bolts.  That's what I did.

David was extremely helpful to me in this whole trying (for me, probably for David, too) experience.  Thank you David.
--
David McNeely