Date: Tue, 5 Mar 2002 08:24:01 -0500
Reply-To: The Bus Depot <vanagon@BUSDEPOT.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: The Bus Depot <vanagon@BUSDEPOT.COM>
Subject: Re: Rear hatch struts revisted. Why do they fail?
In-Reply-To: <022101c1c403$c7602f00$6401a8c0@vista1.sdca.home.com>
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Okay, more than you ever wanted to know about hatch struts ...
Here's what I have learned about hatch struts, after selling a few thousand
of them. Yes, this is empirical evidence, not scientifically proven, but
based on a very large sample size.
I'm not sure why VW went to a dedicated left and right strut (left side
weaker) on later Vanagons.
Early Vans used two standard duty struts (251 829 331A). Shortly into 1982,
they replaced this setup with a weak left / strong right configuration, a
251 829 331B on the left and a 251 829 332 on the right. What is the
difference between the "both-sides" 331A and the "left side only" 331B?
Originally, the difference was the position that it mounted (which side had
the hole and which had the tab). The later one matched the mounting
orientation of the right-side 332. Also, there is a big price difference
(from the dealer), as the 331A retails for $78, versus $33 for the B. This
is probably attributable to the fact that VW changed suppliers when they
went from the A to the B, and not to any real difference in manufacturing
cost. Other than manufacturer and mounting orientation, there is no
difference that I have ever seen between the two versions. And in the
aftermarket the 331A and B interchange, so any differences that may have
existed 20 years ago, no longer do anyway. For what it's worth, the one we
ship is sold as a 331A (but also crosses to a 331B).
Why did VW switch to a weak strut / strong strut combination? I've never
spoken to anyone who knew for sure. Some have said that it was to support
the optional rear wiper, but the data on the fiche does not bear this out.
More likely VW simply did it to increase service life, I would guess. I
will say that I have never heard that "one side raises the hatch and one
lowers it." My initial reaction is that this is highly implausible and
probably the wild guess of somebody who has no more clue as to why VW made
the change than I do.
When replacing the struts, you can use any of three configurations. As VW
did, you can use two standard struts (251 829 331A), or a weak left / strong
right configuration (251 829 331A on the left, 251 829 332 on the right). I
have not found that using the latter configuration makes the hatch
significantly harder to open/close than using the former. I have found that
it does seem to increase service life somewhat.
The third choise is to put the heavier duty right-side strut (211 829 332)
on both sides. This is what most of my customers do. This will make the
hatch a bit harder to open and close. The difference may be more dramatic
at first than after a little while when they wear in slightly. Using two
heavy duty struts will make it stay open better, even able to support a bike
rack (without bikes). It also tends to allow the hatch to stay open in any
position, which can be useful when camping, etc. In my experience, two
right struts will last notably longer than a left/right pair. I have had a
_very_ small number of people complain that this arrangement made the hatch
too difficult to close. Not surprisingly, most of them were petite women.
So if you are a petite woman, or your significant other is, you may want to
consider the left/right arrangement.
I have seen (and sales have confirmed) that it is more common for a strut to
fail prematurely when only one is replaced at a time. Why? My theory is that
the side that isn't replaced is either already weaker than it should be, or
at some point becomes weaker due to age, forcing the new strut to handle
more of the weight than it is intended to, which in turn causes the new one
to fail more quickly. Therefore I recommend replacing them in pairs, which
seems to result in the longest lifespan. Otherwise you end up replacing one
at a time on a much more frequent basis.
Is there a difference in brands of struts? Well, there have been mixed
reports on the aftermarket brands on this list; some have reported that they
lasted fine, others reported early failure. There is not enough brand data
to identify which non-OEM brands last and which don't. And I cannot provide
any input there since I have never sold anything but the OEM ones. But
assuming comparable build quality, the performance of a strut is determined
by its pressure capacity. The lower its rating, the less weight it can hold,
which will mean the hatch will close more easily and it will probably wear
out sooner. Probably some aftermarket companies are just selling
off-the-shelf struts that don't quite match VW spec, but are "close enough"
in their estimation, hence the early failure. Rather than chance it, I just
sell the OEM ones, since the price is about the same anyway.
- Ron Salmon
The Bus Depot, Inc.
(215) 234-VWVW
www.busdepot.com
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