Originally Posted by Hendrika
why does everybody say get the rear leaf spring instead of the add a leaf?
I am going to take the other side of this discussion.
Many Web Wheelers
simply repeat what they read someplace on some 4x4 forum and have no actual experience
with the AAL.
A severely sagged stock leaf spring
will in fact,
be harder on any
AAL than a stock leaf spring pack in decent condition. That is simple physics and plain common sense. Success with an AAL
lift can, and will, depend on the condition of your original leaf pack and
with the AAL type used (short overload leaf type or a long full length leaf), and brand name of the AAL. A short AAL
has to very stiff
to lift the rest of the saggy stock leaves. I think the first Cherokee AAL kits were the short overload leaf types, and this may be where the bad ride, quickly sagging, Internet stories started. A Short Leaf/overload leaf AAL also concentrates its lift effect near the spring eyes of the original stock main leaf which are already under stress and prone to sagging even on stock XJ's with little to no off-road usage . A Full Length AAL
on the other hand, spans between both spring eyes and reduces the weight load each leaf below it has to carry. Spring sag usually begins at the ends of the main leaf near the spring eyes, and progresses to the smaller leaves flattening them out. XJ Cherokee factory original leaf springs are well known to be prone to sagging even with 100% street use. The spring rate or stiffness of a full length AAL will be less than a short AAL. It will ride a little more firmly than stock, but shouldn't be objectionable with good quality shocks.
I have owned or helped my Jeep Club buddies repair or install all types of lift. Our local Cherokee club has 14 lifted rigs and I have owned and built 3 lifted Cherokees and a lifted CJ-7. My XJ started with extended shackles
on factory stock leaf packs and so did one of the local XJ's. A week long 4x4 trip proved that the extended shackles will sag and ruin the stock leaf springs very quickly. With a replacement lift kit spring that is designed to handle the extra flexing and load carrying of an off road 4x4 trip, extended shackles are just fine, and actually help smooth the ride and increase the flex. One of the local XJ's had 2" lift blocks and not only did the leaf spring sag, it went S shaped from axle wrap and then it cracked the main leaf in two. We just built a bastard pack
for another Cherokee using an S-10 spring pack and the original Cherokee Main leaf. This set up works well on the road and trails and gives a little over 4 inches of lift. It gives a smooth ride and reasonable flex on the 4x4 trails. You can vary the lift height achieved by using fewer S-10 leaves or by mixing and matching S-10 and XJ leaves. Another XJ with a 3" AAL and and extra stock Cherokee leaf flexes and rides very well and has not sagged at all.
I ran a Bastard Pack
built from a Full Length 2.5" AAL from Rubicon Express on some un-sagged stock XJ leaf packs along with an extra stock XJ leaf on my 2000 Cherokee. This netted me a little over 3 inches of lift. I ran this lift on two different week long trips to Moab, and a week in the central Colorado Mountains, and regularly hauled 300+ lbs of cargo. It did well on the trails and never sagged in the least in the 3 + years this set up was on my Cherokee. It was maybe 10-15% firmer than stock, but it was smooth on the roads. My current RE 3.5" lift kit Replacement Leaf Spring packs are smoother and flex better than the AAL, but they also cost more than the $100 total cost I spent buying and installing the RE 2.5" AAL.
dependent on your choice of shock absorbers and the brand name of lift parts you install, than on the actual type
of lift parts, AAL vs brand new lift spring pack. The cheaper brands of lift parts have a tendency to be more stiff riding. All lifted vehicles will ride differently than stock and you should expect some compromises and/or changes in ride quality when driving a lifted Cherokee.
contribute to axle wrap and are the least desirable lift option. Lift blocks are also the most likely lift option to cause excessive leaf spring sagging due to the addition of axle wrap to the lift equation. An AAL does not contribute to axle wrap and will actually help prevent spring wrap.
The brand name
of the lift kit parts you choose for your lift will
have an effect on its lifespan of the parts, and on the quality/stiffness of the ride, both on or off road. The only
way to make lift parts cheaper is to reduce the quality of the materials used to make those parts.
Over flexing any leaf spring will cut its lifespan dramatically, no matter what type of lift you install. Leaf springs simply cannot deal with the stress of over-flexing due to inadequate bump stops. So take note, no matter what type of lift you use, you are still required to extend your bump stops
and you may need to buy additional parts not provided in the kit you purchase.
Your lift decision should be based more on your budget, and performance goals, than on any Internet mythology. If your leaf springs are in good condition, an AAL is a reasonable choice to add lift and will meet the needs of most 4x4 users.