4wd Suburban UCA question

[Alex33]

Hi guys, I'm going to purchase a 2000-06 Suburban w/ 4wd. I had a 2000 Yukon 2wd for about 5 yrs and did a lot of suspension work to get it as low as possible but I always hated the torsion bar setup. I'm looking at doing the Z71 rear springs, maybe a spacer and coilover conversion up front for a 2.5" lift. The plan is to run a 33-34" tall tire on a 17" wheel. Everything seems pretty easy but I've been reading that for anything over 3" of suspension lift on a key crank (same as cranking installing a taller coil spring) the ball joint and front driveshaft angles will be pretty horrible and the upper control arms will be on the lower stop. Is this really something I should worry about or have most of you had no real problems with the upper control arms and a 2.5" key crank? Thanks in advance.

 

[Martinjmpr]

I've been running 33's (285/75/16s) for over 2 years on Z71 springs and aftermarket torsion keys. I also have Bilstein 5100's all around and extended swaybar links in the front.

As you can see from the picture, the 33's don't really fill up the wheel wells. I'm pretty sure I could run 35's if I wanted to:

 

[Alex33]

That is actually the stance I am looking for, maybe a hair taller. In a perfect world I would do 3.5" up front but it seems like these trucks don't like that. I do think a 6" lift with the drop xmember is a bit much for my goals and would cause more damage than good. I plan on doing a lot of trails with this truck, no major rock crawling but I know the closer to stock you keep things the longer they will last. No problems with the droop stop at your height? Thanks @Martinjmpr

 

[Matt_]

You're not going to have any down travel left of the front suspension, so the front end is going to be diving/bouncing all over the place on those trails. Guys get more droop by installing aftermarket UCAs and/or cutting the stops. For a beater or 3rd vehicle I guess that's fine, but the front end components go bad really quick. At a minimum you'll also want pitman and idler arm supports.

IMO for what you described, and since you're willing to shell out cash for a coilover kit, go with the 4-6" Cognito NTBD lift and set it at 4" then call it a day. You'll have stock (flat) suspension geometry, torsion bars stay tucked in the frame, full range of down travel for use, it comes with the pitman/idler supports which also helps when running larger tires. You can also get more travel if you run the kit with their Fox 2.0s and Boxed UCAs, the Fox's they spec are designed to be the droop stop instead of the UCA, adds about another inch or so.

 

[swathdiver]

I've been running 33's (285/75/16s) for over 2 years on Z71 springs and aftermarket torsion keys. I also have Bilstein 5100's all around and extended swaybar links in the front.

As you can see from the picture, the 33's don't really fill up the wheel wells. I'm pretty sure I could run 35's if I wanted to:

Looks perfect to me!

 

[Martinjmpr]

That is actually the stance I am looking for, maybe a hair taller. In a perfect world I would do 3.5" up front but it seems like these trucks don't like that. I do think a 6" lift with the drop xmember is a bit much for my goals and would cause more damage than good. I plan on doing a lot of trails with this truck, no major rock crawling but I know the closer to stock you keep things the longer they will last. No problems with the droop stop at your height? Thanks @Martinjmpr

FWIW I think the rear end sits a bit low for my taste (especially when fully loaded and pulling a trailer) so I've got some 2" spacers in the garage, just waiting for a free weekend to put them in (and while I have the coils out I'll remove the air bags I put in last year - they really don't work for me and I ended up going with a WDH for the trailer anyway.)

I think I posted my components here when I did the lift in 2016. As I said, brand new Z71 springs to replace the tired LT springs, brand new Bilstein 5100's on all 4 corners, lift keys from eBay and Moog sway bar extenders. I'm pretty sure my total cost was under $500 and most of that was shocks (4 @ $80/ea.) Did it in my garage except that the factory T-bar keys were so badly rusted (thanks to the truck spending 8 years in Wisconsin!) that I had to take it to a shop and have them bust the old keys loose with a power hammer and then install the new ones. Cost me $150 but well worth it.

I actually do take my Suburban off road in Colorado, Utah and other nearby states. That's also one reason I went from the factory 17" wheels to 16" because I wanted a bigger sidewall since I air down (and it doesn't hurt that going to 16" saved me about $200 on a set of new tires!)

 

[Alex33]

@Matt_ which lift are you talking about? I didn't see it on their site. Seems to be full of 2500 and 3500 truck stuff.

@Martinjmpr that still looks pretty good. would you go with a larger tire after you add the 2" of height?

 

[Matt_]

@Matt_ which lift are you talking about? I didn't see it on their site. Seems to be full of 2500 and 3500 truck stuff.

My apologies man, looks like they only make the 7-9" kit for for 1500s... I could have swore they made the 4-6" too, because I wanted it when I converted my 1500 from cranked keys to 4" lift (I went with Superlift because I got a great deal that I couldn't pass up).

As an aside, you can also gain a lot of tire clearance with fender mods, when done right are not visible (not hack jobs).

 

[Martinjmpr]

@Martinjmpr that still looks pretty good. would you go with a larger tire after you add the 2" of height?[/QUOTE]

No, I'm pretty happy with the 33's. I can't see any benefit to 35's. The primary duties of the Suburban are (1) pulling our travel trailer and exploring the areas where we camp once we get to our destination and (2) hauling my butt to and from work 3 days a week (I work from home the other two.) I'm not going to compromise the overall comfort of the vehicle just for bigger tires.