about this setting of the t-bars...
do they drop in height by just sitting there in your driveway, or does it take some bumpy wheeling to drop them?
and this should be expected for the first few months or so?

I think more a mixture of both, making the front flex a bit will help them to settle a bit faster.

Mine have been settling by simply driving on pavement. I adjusted them 2 nights ago for the 3rd time. Once again I adjusted them so the bump stop was 1/2" from the UCA, but this time I drove it a couple miles after each adjustment. Every time I pulled back in the garage it had settled more. Finally they stopped dropping and I assumed/hoped the settling was done. I was wrong, the passenger side is about 1" from the UCA today and the driver side barely dropped. I'm going to readjust again tonight and hope that they are finally done.

Are you guys preloading the bars during installation ?

When you install them, don't do it with the control arms hanging, they need to be fully compressed.

No, I guess I didn't do that. Mine seem to have settled now anyways after being crenked back up 3 times. I guess if I had done it right the first time that wouldn't have happened.

Mine were done with the control harms hanging too When I put tension on the bars with full vehicle weight I was afraid the tension bolt would fail (strip/break). The pressure required to lift the truck seemed too high. I guess that may have been the problem, thanks Ian.

If you can't turn the adjuster bolt by hand with an 18" wrench, it may be time to replace them (about $5 each). They should be rather easy to turn.

You're not going to have the full weight of the vehicle on it when installing, simply place the front of the Xterra on jack stands, then jack each arm up as you install the torsion bar.

I didn't use my breaker bar, I used a regular length 3/8 ratchet. It makes sense to do the adjustment with jack stands supporting the truck and a jack applying pressure to the A-Arm. Thanks for the info.

Ron

Yes Ian, my truck was fully on the ground.

Mine was fully on the ground as well which might explain why mine have not settled as much as you guys. But doesn't explain off2cjb's experience though

From what I've seen all torsion bars will settle over time. I've had SLR bars for just over a year and I still have to crank them up every couple of months. I don't see how installing them with the truck jacked up or on the ground will affect this. I've cranked them both ways and it hasn't mattered. I normally set the ride height then back out of the driveway and run over the curb several times and recheck the UCA gap.

Stupid newbie question...

How do you adjust the torsion bars? I am considering the lift, but I have basically no tools here other than a set of wrenches and screwdrivers--certainly no major automative tools. Do I jack it up and turn some bolts? From reading the thread, I should expect to have to readjust the T bars every few months, sound right? Or is that only if I don't "pre-load" them?

Argh.

This is on a Frontier, but it should be the same for your truck: http://www.nissanoffroad.net/frontier/how_to/torsion_bars/default.asp

I talked to Steve from Calmini last night and he gave me some good information. He said since my alignment is completely off there is a good chance that my font end is actually toed out rather than in a couple degrees like it should be. If the front end is toed out the tires pull the front end down while driving forward. He said if I reverse a few feet before checking the bump stop/UCA measurement I may notice that the front end is higher. I took Steve's advice and sure enough the front end measured higher. I scheduled an alignment for Monday.

He also recommended that I find a place that would really compress the suspension and drive it a few times. There is a road near my house that has a nice dip that isn't harsh, but really compresses the suspension. I hit this about 10 times, and when I checked the front end afterwards it had settled noticeably again. I readjusted the T-bars to Steve's recommended 3/8 -7/16" from the bump stop. Hopefully these bars are close to settling in. I would like to thank Steve for his great customer service.

Ron

Let me add some fuel to the fire. For you guys running 3/8 to 7/16 gap, do you get a vibration while on the gas? I set mine up that way and in 2wd no problem, when I shifted into 4hi the faster I tried to go the worse the vibration got. I had to lower the front to 5/8 gap and still get a little vibration. It never did this before the lift and at my current setting it is ass high and driving me crazy. Any help on this would be great.

As you raise the front of the truck, the angle of the axle shafts will increase. The ends of the axle shafts have CV joints. On the wheel side, it's an Rzeppa Joint, which is essentially 6 large balls in a cage. On the diff side is a tripod joint, which is a telescoping design of 3 bearings that allow the axle shaft to move in and out as it travels through an arc.

As the angle increases, the Rzeppa Joint can cause vibration due to how the balls travel inside the joint.

If you look at a stock height Xterra, you will notice the axle shafts are almost parallel to the ground, which is how they are designed to work. They spend very little time at extreme angles, so vibration is rarely felt.

They only solution to decreasing some of the vibration is to lower the front diff, which will decrease the angles, but not enough to get the axle shafts back to their stock angle.

When in 4WD, the road surface is usually something other than pavement, and speeds are usually low, so I find it not to be much of an issue.

This past winter I noticed a vibration when I accelerated. The more gas I gave it the worse the vibration. It wasn't there at all when I was cruising at a steady speed. It turned out the tripod joints had worn a notch in the tracks they move in.