ProComp ZJ lift kit

[TiggersBounce]

Mostly bad and ugly here. Its a nice street kit, for those who seldom (if ever) take their ZJ off-road, and handles well. But if you are into moderate wheelin' then you are going to run into problems.

LCA: Dogleg style, supposed to give more droop. The design bypasses the OE suspension stops, which are there to protect the drivetrain from damage. Exploding front CV joints are one result that is expensive to fix.
While on the LCA, the hollow tubular design does not flex well. Not even as well as the OE LCAs. But we'll get back to that.
Oh, and the frame end width is too narrow, probably OK for a XJ but fails to take into account the different design of the ZJ. You wind up using shims or bending the crap out of your frame end brackets to get them tight.

LCA bushings: Hard, small diameter, urethane. Very little 'give'. Combine with more rigidity in the LCA itself, and you have a design which has less ability to flex than OE, and transmits more stress to the frame end brackets. All in all a bad combination, one that not only performs bad off-road, but increases the risk of damage if you wheel hard.

Front track-bar relocation bracket: This thing is just plain trouble in disguise. When you lift, the track bar anchor at the axle end needs to be relocated if you use the OE track bar. Easy enough. But ProComp wanted a bolt-on bracket. So, they needed to move the anchor inboard, and because of things in the way, they also moved it 2" downwards. So now the other end (ball stud) of the trackbar has the angulation of a 5" lift!! This is just on the street. Now start wheeling, and droop the passenger side ... ballstud runs out of angular travel very quickly. More stress, strain on the trackbar and the bracket. There is a significant risk of damage here.

Rear trackbar relocation: None provided. Huh? Whats up with that?

Springs: Same unsprung length as OE. Larger diameter wire. This equates to a higher spring rate to gain the advertised 3" lift. Unfortunately this does nothing as far as adding the flex that would make the dogleg LCAs useful.

Enough for now. Be warned. There are other ways to get a 3" lift. ProComp is not alone in utilizing some/all of these poor design practices. So, while this is focussed on the ProComp in particular, let it serve as a checklist when evaluating kits by other manufacturers.