"Z" Height Measurement

[55 Nomad]

Does anyone know or have access to the "Z" height measurement for a 2006 Chevy 3500 RT Versatile 190 4x4. I have contacted Quigley who gave me the alignment specs, Chevy has nothing because they didn't install it, the alignment shop doesn't have this information and I have found nothing on the internet. I am thinking maybe use the Silverado specs because it is Silverado parts installed. This is used to set the ride height which also the alignment is set to. Thanks

[booster]

Originally Posted by 55 Nomad

Does anyone know or have access to the "Z" height measurement for a 2006 Chevy 3500 RT Versatile 190 4x4. I have contacted Quigley who gave me the alignment specs, Chevy has nothing because they didn't install it, the alignment shop doesn't have this information and I have found nothing on the internet. I am thinking maybe use the Silverado specs because it is Silverado parts installed. This is used to set the ride height which also the alignment is set to. Thanks

I can't say that I have ever seen that for a Quigley, either. IIRC, it was stated that the Roadtrk 4X4 was about and inch higher than a stock Roadtrek, but it wasn't stated if that was before or after the conversion. Stock Roadtrek two wheel drives sit nearly 2" below the factory Z trim height. I would have to look up th factory Z height in factory service manual for two wheel drive, but it would give about 35.5" high at the front wheel wells with the stock 245-75-16 tires.



I think the Quigly is torsion bars in front? If so you can easily change the height so you may want to start at maybe an inch above factory 2WD spec and see how the upper and lower control arms are sitting when on the wheels. The 2WD ones have positive resting camber and progress to more positive under compression (bumps or outside wheel in turns), so the upper arm would be pointing down a ways from horizontal. If you find the upper arm is horizontal to slightly up, it is likely it will go more negative on compression. If it progresses negative camber you would want to align it with slight negative camber. Positive camber will give easier turn in and maybe a bit more stable straightline. Negative will increase turn in effort and improve cornering traction, plus may give a bit more center "feel" to the steering.

[55 Nomad]

Yes it has torsion bars that I know can be adjusted. I am presently sitting at LF 36 1/2 and RF 36 5/8 with 265/75R16 tires. If you subtract 0.6 that would put the fender wells at about 36 for 245/75R16 tires. Camber is about +0.50*, caster +3.75* and toe in +0.06". This is what Quigley gives for specs and my alignment shop got it right on. Quigley says they replace the lower control arms and reuse the upper control arms. knuckle, shocks, sway bar and all the steering. I measured the Z height and it has L 3.0" and R 3 1/8" but I don't have anything to compare it to. The none Express parts are new GM 2005 Silverado 3500 parts. Quigley has been very helpful.

[booster]

That is pretty high on the caster, but may be typical on the 4 WD to get better holding on slippery surfaces. On pavement it may make for uneven tire wear, though,


You are actually sitting at just about factory ride height plus one inch, I think, so if you the unconfirmed information I heard in the past was correct you would right on if that information was based on an unconverted van, You would be nearly 3" higher than a stock height 190 Roadtrek. All this is based on the fenderwells. We have and 07 190 with a spring lift of about 1.75" in the front and with our 265-75-16 tires we are at a bit over 35.5" at the front fenders.


We have heard of some spring lifts in height you have being done lately, as the springs have changed lately from the vendor, and that height seems to be OK for them but getting close to being too high to prevent upper A arm to frame contact on extension. With stock uppers on the 4WD setup, you may want to take a look if the upper is staying away from the frame at full droop. The 2WD does not have a down travel stop as such, they stop on the shock, so long shocks can allow them to hit sometimes. I don't know how they do the 4WD stops.

[markopolo]

Z trim height looks to be 4.0" - 4.5" allowed and 4.3" preferred.

Source-> https://workshop-manuals.com/chevrol...pecifications/

Comes up the same for other years -> https://workshop-manuals.com/chevrol...pecifications/

[55 Nomad]

Booster I did a drop check on the passenger side and the upper A frame doesn't make contact as I can slide a piece of card stock between. Markopolo If I crank the torsion bars up 1.3" from 3 to 4.3 as the book says wouldn't that put me on the stops?

[markopolo]

Hopefully Booster can help answer that as I don't know much about it.

[booster]

Originally Posted by 55 Nomad

Booster I did a drop check on the passenger side and the upper A frame doesn't make contact as I can slide a piece of card stock between. Markopolo If I crank the torsion bars up 1.3" from 3 to 4.3 as the book says wouldn't that put me on the stops?

If the 4WD setup is like the 2WD, the downtravel is set by the shock length so changing the non drop setting of height shouldn't really have an affect on it. What you will lose by going higher is downtravel amount before the shock stops the travel. If you get to little downtravel, you stand a chance of topping out the shocks too much as they will be doing all the stopping of downtravel. It will get noisy and probably beat the shocks to death. Most people seem to like to have close to at least two inches of downtravel.

People get in trouble because they try to increase their downtravel after a lift by getting longer shocks and don't realize that they risk the frame contact.

Depending on how thick your cardboard was, you may be getting pretty close to hitting, so probably can't move the shock down any more. The wheel will drop a bit further when hitting a deep hole as the shock mounts will deflect a little when it drops with the weight on it.

[55 Nomad]

I used a business card for clearance. I believe that it also uses the shock as a stop. I disconnected the lower shock mount and the lower A frame dropped to the upper A frame hit the stop. I have factory shocks in it now and installing Bilstein on all 4 corners next week.

[booster]

Originally Posted by 55 Nomad

I used a business card for clearance. I believe that it also uses the shock as a stop. I disconnected the lower shock mount and the lower A frame dropped to the upper A frame hit the stop. I have factory shocks in it now and installing Bilstein on all 4 corners next week.

A business card is probably not enough for when it comes down with momentum as it is probably 1/32"? When you do the Bilsteins you should be able to get a bit of downtravel adjustment by adding washers to either above or below the top of the mount. Once you look at it that will probably get obvious where to put them to go each way. I think about 1/4" at full drop would be good, IIRC what is commonly said on the pickup forums.


Be sure the Bilsteins came with big style factory top mounts, as in the beginning they didn't and pounded out right away. Those mounts have an internal sleeve stop inside them so pull them up tight until tight. You will fell it hit solid.