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Simon,<br>
<br>
I repaired my BJ8's seat runners a few years ago. Working from
memory (so a few things might not be exactly correct):<br>
<br>
1) there are pins on each end of the bottom to keep them from going
too far/coming apart; I got these out, I think by knocking them out
with a drift (be prepared to catch the ball bearings)<br>
<br>
2) once the tops/bottoms of the slides are separated, the old
studs/bolts can be removed by grinding their heads down (I used a 3"
compressed-air cut-off tool)<br>
<br>
3) put new bolts of proper diameter and length(IIRC, 5/16 x 1" or
so) into the holes you created in #2 (recommend grade 5; grade 8 may
not weld too well)<br>
<br>
4) tack weld the new bolt heads (small bead on two sides in
lengthwise direction; I think the runners may be galvanized, so do
not breathe the fumes--respirator would be a good idea)<br>
<br>
5) use the cut-off tool to grind the new bolts' heads and welds down
enough so the runners can slide<br>
<br>
6) I used suitably-sized roll pins to replace the end pins removed
in #1--will make it easier to re-do if necessary*--don't forget the
ball bearings; they have to be installed 'just so'<br>
<br>
There were a couple small gotchas--that I don't recall exactly--but
they had to do with 'order of replacement;' so pay attention/take
photos when you disassemble. Overall, a satisfying project; esp.
since new ones aren't cheap. The ball bearings are 5/16" and, of
course I lost a couple; I bought a boatload of these from a bearing
house, they're used elsewhere (including in gearboxes).<br>
<br>
Bob<br>
<br>
* Of course, I immediately stripped one of my new bolts before I
realized the power of my new battery impact wrench.<br>
<br>
<br>
<div class="moz-cite-prefix">On 12/31/2020 10:30 AM,
<a class="moz-txt-link-abbreviated" href="mailto:simon.lachlan@alexarevel.plus.com">simon.lachlan@alexarevel.plus.com</a> wrote:<br>
</div>
<blockquote type="cite"
cite="mid:000001d6dfa2$f81378d0$e83a6a70$@alexarevel.plus.com">
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<p class="MsoNormal">Happy New Year to one and all, <o:p></o:p></p>
<p class="MsoNormal">(I always think of Eddie Murphy in “Trading
Places” when I hear that!)<o:p></o:p></p>
<p class="MsoNormal">So, we’re talking MkII BT7 here….<o:p></o:p></p>
<p class="MsoNormal">The bolts that fasten the seat bases to the
runners in my car are pretty ratty. One or two are missing and
several have had their diameters reduced and rethreaded.
Presumably after wearing out. But the slides work and they’re
fully functional.</p>
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</blockquote>
The OEM studs have all the strength of wet noodles.<br>
<blockquote type="cite"
cite="mid:000001d6dfa2$f81378d0$e83a6a70$@alexarevel.plus.com">
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<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal">What is the precise anatomy of these
things?<o:p></o:p></p>
<p class="MsoNormal">The bolts that come up from the part of the
runner that moves fore & aft, are they spotwelded in
place?</p>
</div>
</blockquote>
Yep. They are a 'special' type, with flat heads and round (no
sides).<br>
<blockquote type="cite"
cite="mid:000001d6dfa2$f81378d0$e83a6a70$@alexarevel.plus.com">
<div class="WordSection1">
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal">Can one split the moving half of the
runners from the fixed half?</p>
</div>
</blockquote>
Yep again (see above).<br>
<blockquote type="cite"
cite="mid:000001d6dfa2$f81378d0$e83a6a70$@alexarevel.plus.com">
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<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal">In which case, I presume one can fix in new
bolts? Remove hidden nuts or grind off welds and MIG on new
bolts?</p>
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</blockquote>
Grind old, weld new, grind new flat.<br>
<blockquote type="cite"
cite="mid:000001d6dfa2$f81378d0$e83a6a70$@alexarevel.plus.com">
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<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal">What size are these bolts?</p>
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</blockquote>
5/16"-24TPI (I think). IIRC, about an inch long (but not sure). Too
long and they'll dig into your seat bottoms (ouch!)<br>
<blockquote type="cite"
cite="mid:000001d6dfa2$f81378d0$e83a6a70$@alexarevel.plus.com">
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<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal">Simon<o:p></o:p></p>
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