Date:         Fri, 13 Aug 2010 18:29:27 -0700
Reply-To:     neil n <musomuso@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         neil n <musomuso@GMAIL.COM>
Subject:      Likely Pop Top Spring Cable Solution (Long, with pic)
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Hi all.

Sorry for the long post. The gist of it is, if you measure all
applicable things, use the right parts, tools and methods, the image
I've linked to should work as a replacement. The ball is swaged on,
but this is considered a mock up of sorts and is untested.

Pic: http://tinyurl.com/24sm6ws

If you choose to make and/or use this part, you do so at your own risk.

Here's what I see as being one possible solution. I don't feel like
taking my pop top struts apart AGAIN.  So some of this is
guesstimating.

The thimble (part inside loop) might be a bit too long causing cable
where it exits the ferrule (the crimp on part) to be bent at a small
angle. This is because it may go around curve instead of flat bit of
arm (see previous pic) AFAIK, the cable shouldn't bend where it enters
or exits a fitting. (termination) But..... guy at yacht place that did
the swage ball, suggested this may not be an issue in this case as the
angle would likely be small. Bottom line: the original part failed,
and 29 years from now, the part shown may well fail. Still, I'd prefer
to use a cable bushing (picture a small pulley) at this end. The
distance from arm face to stop pin (pin that stops the motion of
struts once top is up) is ~ 11mm. The height of thimble, washer and
bolt head will hopefully be less and will clear the pin when top
pushed up. BTW, as seen in another members post, these parts wear. I
repaired mine so it's dang close to original. The 11 mm I roughly
measured MAY NOT APPLY to your struts. They may be quite worn.

Other end is a bolt I ground down (no lathe!) and drilled a hole
through. The shank of swage ball end fits into this hole. I will
counter sink bolt head where ball seats. And even though the cable
should be a straight pull through the spring, I will counter sink or
chamfer hole where cable exits. I may push some silicone through too.
The stock piece might be useable in the same fashion, but I'd be
curious to know just how much the strength of the end would be
compromised by countersink. I cut a coil off the spring and ground end
"level" to allow for the longer bolt head/ball combo. The head on the
factory part is ~ 4.3 mm. There is ~ 4 mm between head on factory part
(no coil cut) and pin that secures strut to lower hinge bracket.
Cutting a coil off gave me an added ~ 10 mm clearance IIRC.

To secure upper end, I'd likely run a bolt through hole where Z was.
There appears to be room on the other side of this hole for a nylon
locking nut.

It is crucial that this nut/bolt stay put!

If total length of cable/terminations is right, even when top up,
there is slight tension on the spring. I assume it was originally
designed that way so Z wouldn't come out of hole. With that said, I
would try to get the new assembly length as close to OEM as I could.

I did a dry run of supporting pop top with post. Top was lowered
slightly onto post. This took weight off the struts. Once done, it's
possible to take apart the arm WITHOUT the cable.

DO NOT TAKE APART ARM WITH CABLE. Even though when top up, the spring
is barely compressed, it just wouldn't be wise to do so.

Parts are all SS - 3/32". The cable (wire rope actually) is slightly
larger than what I removed. The shop used 7x19 wire. Ball on end is a
shingle shank swage ball. Google will show you the way on that one.
This part ABSOLUTELY has to be swaged on and the ferrule ABSOLUTELY
has to be installed with the right tool. A cable wire (wire rope) shop
or marine rigging shop will help you with this.

I asked dealership recently about this part. It's NLA, but was listed
at ~ $45 Cnd. Parts cost for mine was around $20. The swage charge
being $10 per.

The swage was done by someone who knows what he's doing. I may go back
and get him to crimp the ferrule. We'll see.

My apologies for all the upper case. Just want to be clear. Hope all
this helps. If someone else needs this part, they would be well served
to measure everything. At the very least, this post should save the
next person some time Googling and such.

I have yet to get my Jack Bombay kit. Once it's in, I may remove the
good cable and see how well things work w/o the stock assist.

Neil.

--
Neil Nicholson '81 VanaJetta 2.0 "Jaco"

http://tubaneil.googlepages.com/

http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines