Cherokee-Ltd wrote:
> "Steve" <xjlifter@bogus.com> wrote in message
> news:383mvrF5kl3slU1@individual.net...
>
>>I almost went with Rusty's for the taller leaf springs, but I found that
>>the RE kit can be ordered with 4.5" springs at no extra charge (actually
>>less if you pass on the shackles). The 4.5" springs cost the same as the
>>3.5" springs.
>
> That's news to me. I called a couple places (admittedly not RE themselves)
> for quotes and asked why they didn't come with 4.5" springs. Never got a
> straight answer.

When I called around, at least one place (maybe mesa4x4 or dpg?) said
that sub was no problem. I ended up getting the kit from national4wd in
Burlington after they agreed to match the US dealers prices + duty and
then chucked in the JKS discos on top.

>>Then after thinking on it, I decided that performance now was more
>>important than hedging on some future upgrade I might never make, so I
>>opted for the 3.5" springs and all the extra flex that the new longer
>>shackles give me. The point is, RE isn't 'cheaping out' by fitting the
>>4.5" kit with 3.5" springs and extended shackles. Quite the opposite, it
>>is done for performance and is actually more expensive than 4.5" springs
>>and no shackles.
>
> Depending on the construction of the new leaf pack, a longer shackle may
> limit flex. The good folks at RE have obviously considered this and designed
> that package accordingly. I don't fully understand the geometry so I won't
> try to -------- you with an explanation - I was able to relocate this info
> on the web. It was very helpful for researching my lift.
>
> http://www.4crawler.com/4x4/ForSale/...es.shtml#FAQ2;
> <copy & paste>
> Three strategies for designing lift springs.
> 1. Keep the stock spring geometry and just use thicker and stiffer leaves to
> gain lift.
> This does give the desired lift but the ride quality is reduced and
> suspension compliance is reduced.
> 2. Retain the stock arc-length (see above) but use more free arch to gain
> lift (an arched leaf will be stiffer than a similar flat leaf).
> The advantage of this design is that it will work fine with stock spring
> shackles.
> 3. Keep the stock chord length and instead use a longer free-arch which
> results in a longer arc-length.
> For this type of spring, you must use a longer spring shackle or else you
> may find the stock length shackle will bottom out on the frame and cause
> excessive stress.

Great link. Thanks. Kind of makes me wonder if RE is having their cake
and eating it too. As far as I know, the 3.5" leafs are the exact same
ones that ship with both the 3.5" kit (stock shackle) and the 4.5" kit
(extended shackle):

From http://www.rubiconexpress.com :

RE1462 4.5" Extreme-Duty XJ Rear Spring (1) : $149.95 + S&H
RE1463 3.5" Extreme Duty XJ Rear Spring (1) : $149.95 + S&H

I wonder which of the two configurations it's optimized for. Might also
mean that using the 4.5" spring in the 4.5" kit might be suboptimal if
it is tuned for the 5.5" kit with shackle. When the snow melts (probably
June, another nor'easter blowing in tomorrow), I'll dig up my stock
springs and compare arc cord/length, freearch, etc.

Steve
http://xjeep.dyndns.org