custom truck mods

Spencer Low Racing 1" rear shackles w/poly
bushings and triple-spring Add-A-Leafs (AALs)

Friction pad and "C" clamp	Full length view of spring pack
Side view of spring pack	Top view of spring pack
Washing the leaves with dishwash soap	Priming the clean leaves for painting
The finished, painted leaves	Finished install on driver side
Differences as compared to 2" shackles alone w/load leaf	Finished view, driver side
Finished view, passenger side	Finished view, driver side, tall

looks involved (read: caution)

Installing new leaves into your existing springpack and adding shackles is a good couple of hours worth of work and not for the novice. You will be working underneath a 4,790 pound vehicle and you'd better have a decent set of jackstands and a hydraulic jack. If you cannot complete the job, your truck isn't going anywhere, short of on the back of a flatbed. Just make sure you can handle this task before getting into it. That having been said...

the components and installation

The SLR triple-spring "Add-A-Leaf" (AAL) solution is currently the best available, IMO. Those from other manufacturers have two, or even only one additional spring leaf and do not have the added features of the ones from SLR like friction pads and loops to contain the springs when they twist. Granted, they are more expensive and come unpainted (an extra step, but it's a small downside) - the results more than make up for this.

Shackles are another method of raising the rear of the truck and can be used with or without AALs. In my case I used the 1" shackles, although 2" ones are also available (more suited for standalone use). IMO, if you're not going with a full 3" lift, which this combination provides, don't be tempted to just add shackles - you're better off using AALs instead, as your ride will be much nicer. However, shackles are easier to install for novices and provide a very quick means of adding lift.

ditch the load leaf

As with most AAL upgrades, you generally remove the "load leaf" from the stock springpack, though you can just as well leave it in. I strongly advise you to remove it! On a stock X, you might notice the truck "hop" over speedbumps and potholes or "bottom out" on dips in the road. This leads to dangerous handling if you're on the highway, for example - and at speed. It's also very uncomfortable and jarring. These symptoms are all caused by the factory load leaf. It is overkill for the Xterra for general use and especially off-roading - but is great if you carry occasional heavy loads. If you use just shackles to to raise the rear of the truck instead of in conjunction with AALs, this problem is even more obvious.

quite settling

After installation of AALs, the rear of the truck will generally sag 1/2" or so at a rate proportional to your use (load carrying, off-roading) of the truck. This is normal as the leaves settle into their new positions. Therefore, don't be alarmed after installing this combination and seeing the rear of the truck way up in the air. To speed this process a little, I bought two 50 pound sealed plastic bags of playground sand and put one in each rear corner of the truck, as far out into the corners as possible. Given a month or three, the rear should be fully sagged. This also depends upon the condition of your stock springs. Folks off-roading a lot report that no matter what, the springpack will sag over time more and more - again, at a rate proportional to your off-roading use and weight carried in the rear. Even the very expensive National spring packs reportedly do this, and they cost $750 alone.

the end result

The end result of these modifications is startling. The rear end of the truck is obviously 3" higher than before now, but the handling is very much improved as well. There is absolutely no more harsh bottoming out and bumps/potholes are virtually soaked up. At first install, the truck seemed kind of tippy, as if removing the load leaf killed needed stiffness in turns. After the AALs sagged into place, and the truck's center of gravity lowered - this feeling went away.