Lengthen a Rubicon Express RE1660 trackbar

What I am confused about is that with the original trackbar joint end, I measured about 1/2" off centre for the axle (w.r.t. fenders), with the axle being more 1/2" more on the driver's side of the vehicle, so with the 1" longer end, I adjusted it so that the axle is 1/4" more towards the passenger's side. This theoretically should have centred the axle, but it didn't. Based off the fender flares, the axle is still 1/2" off centre, though the JKS Quick disconnect angles looked a little a bit better. So what is going on here?

Is the centring force of the upper/lower control arms and springs much greater than that of the trackbar; to the extend that adjusting the trackbar moves the chassis upward instead of outward? If that is the case, I can see why the ACOS on the passenger's side had to be adjusted 1" longer than on the driver's side to get the vehicle level. I still do not understand what is going on here and why.

This is how I take my measurements. I recommend you to do the same. (Not trying to be rude)

Support front axle with Jack stands.
Remove wheels and tires.
Bolt rotors on tight to unit bearing
Take a straight edge (I use a cheap framing square) on the rotor hat.
Use a tape measure from the square to the frame in a straight line. (Don't forget to account for the trackbar bracket if you measure to it)

I actually cheat mine.25" driver to help clearance things. It has no affect on the drivability.

The control arms have much less authority than the track bar on centering the axle, but after making an adjustment I jump up and down on the front bumper to settle everything.

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Yes, measure to the frame not the fenders. You should be able to find some factory feature that is identical on each side like a stamped hole, edge, or sheet metal seam. I would also level out the ACOS on each side before measuring. My axle is purposely off center to prevent the driver side coil from rubbing against the TB bracket...not a big deal to have it off center.
When all said and done, make sure you have enough thread engagement on the TB.

Next time I'm under there, I'll try to get some contraption setup to measure to the chassis. Probably in a week or two. Unless there is some asymmetry with the body around the fenders, the results should be similar.

It may be that my lift height is closer to 6". My front springs are Rubicon Express 4.5" springs. One the DS, the JKS ACOS is on the shortest setting now - which provides what, 1.5" of lift? That spec is hard to find. That would make the front 6" of lift. I just levelled the car out again (it has been 15 yrs afterall) and the PS ACOS is adjusted 1-5/8" taller than DS for a level ride. In the rear, I forgot that the 4-deg axle shims I have have some slight lift in them as well, so the back lift would sit at 5.75", not 5.5".

Another poster, RCP Phx, mentioned he has a similar setup to mine, which I assume that means 5.5"-6.0" of lift. He also said he needed the 1" longer trackbar joint end. RCP Phx, do you recall how much engagement you had before your front axle centred?

I've left mine at 15/16" engagement. Levelling out the ACOS (shortened the DS ACOS all the way), I now only measure 1/4" off centre for the axle as based off the fenders - not the 1/2" I measured before. This is probably good enough for me, but I am curious how much engagement RCP Phx has on his [similar] setup. It just seems odd that the standard RE trackbar says it can accommodate 5.5" of lift, when in fact I needed a 1" longer bar.

lordoeuf said:

It just seems odd that the standard RE trackbar says it can accommodate 5.5" of lift, when in fact I needed a 1" longer bar.

Click to expand...

Marketing.

Scott Adams nailed it when he called it another word for fraud.

Never trust what the marketing folks say.

Lordoeuf, I don't remember how much thread is in mine, I bought those extended couplers about 15yrs ago and never did install them. My RE lift sits at exactly at 5.5".

I see, so you are using the standard RE joint end.

I guess I will disconnect the trackbar, jump on the front bumper, and check the level to ensure that the lengthened trackbar isn't effectively lifting the driver's side. This could explain why the ACOS on DS is adjusted to 0" while the PS is at 1-5/8" to achieve a level chassis.

This thread kind of gives me hope that my RE1660 track bar will be short enough to run with 3-4.5" of lift instead of the 5.5" as advertised