Considering Lifting My Suburban

shifty98

Observer
Currently I have an 04 Suburban 1500 4WD LT. It is pretty much bone stock except fender flares, tow mirrors, radio head unit, and rear air bag suspension. It is approaching 300,000 miles. Currently it is my daily driver but that could change soon. I plan on replacing the current set of tires before next fall and discovered today that I am in need of new shocks. I figured this is probably a good time for me to consider lifting it. I am not looking to build a monster rig at all. Just something that will get me where I need to go to have fun outdoors. I am currently thinking of going with a 3" suspension lift and 33s. I wouldn't mind running 35s but I would like to keep the cost low because I am a college student and don't want to throw a ton of money at a 300K truck. I just want to be able to get off the beaten path without beating up my undercarriage. That said it runs really well so I want to not be afraid to take it off road and right now my main concern is clearance.

Here are my questions:
Any suggestions as far as lift goes?
If I do lift it are there any other costs to consider besides the cost of the lift and tires?

Here is what I am looking at.

https://www.amazon.com/dp/B01AHR74M2/ref=psdc_3150551011_t2_B01AX9FSCW
 

Matt_

Observer
I've been in your shoes, on my 2005 Silverado back in college I did the cheap torsion bar "lift" with shocks and 33s. Told myself the ride was good, it but wasn't, and I knew I was screwing my front end up, especially when wheeling... lack of travel made washboard firerpads roads really rough, and the front end just got knocked around if a tire found a rut in mud holes . Within a year I went with the full suspension lift and was much happier. Then when my 33s wore out I went with 35s.

If I were you (me), on a budget it's hard to beat the Rough Country lift kit. It's not much more pricewise than keys & shocks. You can set the lift at minimum height to run 33s and have nice flat suspension geometry, plenty of travel for uneven terrain, and you can bump it up to 6" if you want to go 35s someday.

http://www.roughcountry.com/gm-suspension-lift-kit-279n2.html

Other expenses to consider are regearing and a programmer for 35s. You can probably get by just fine with 33s, but a tune would still be a good idea
 
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rayra

Expedition Leader
keys work fine, as long as you stay away from maxing them out. Get too steep an angle on the IFS and of course it rides bad. I did mine, kept it to a moderate amount of lift and it rides nice as it ever did. Ended up with about 2" total, at a very low price. Still on stock size tires for my Z71, 265/70-17, ~31.5". 14"+ under the frame. Works for me, but I don't bash around. 'broke college student' can't afford much more than that anyway.

suburbanlevel170109.jpg
 

Matt_

Observer
I only went up around 2" with mine, didn't max them out, didn't use aftermarket keys for more crank either. Drove fine on the road but I did a lot of offroading and exploring along fire roads (which get horribly washboarded) back in those days.

OP is looking for 3" and 33s... that'll definitely be maxed out. I trimmed to keep the front lower
 
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shifty98

Observer
@rayra Did you lift it at all or just crank up the keys?

I have turned up my keys just to see what I would get out of it. It only raised my truck 3/4 of an inch. That would be enough to clear 285/70/17s for sure but I would like to go up a bit more than that. I don't bash around much, mainly looking to drive fire roads and in the midwest, they can get pretty muddy sometimes so I want to be able to run bigger tires to be able to float over muddier spots and an occasional creek crossing.
 

Matt_

Observer
@rayra Did you lift it at all or just crank up the keys?
.

Unless you get a full suspension lift, it's all just "cranking keys". Lift keys are merely indexed further than stock keys, so they let you crank (twist) the torsion bars further than stock keys allow.

If you're only looking to run 285/70/17 you can probably fit them now on stock wheels and with some minor trimming. I wouldn't go higher than absolutely necessary to maintain as much down travel as possible. Google the Norcal fender mod for good instructions (FYI they didn't invent it, but kudos to them for making it a mainstream mod that some once considered a "hack")
 

shifty98

Observer
Ok, that makes sense. I looked at the Norcal Mod, thats smart. I'm going to suggest it to my Dad who put on tires a little bit too big and they rub a little.

I was hoping to run at least 295/75/17s. I figure if I'm going to replace the suspension I might as well do it right and give myself more options down the road (pun intended). I figure I could put a 3" suspension lift and then still 285s if I for some reason wanted to. One thing I also thought about it being smooth and having a good ride which is why I would probably do a suspension lift.
 

Matt_

Observer
Man I'm telling ya, with the tire sizes you're talking about running, that RCD lift is tough to beat. Great price, great reviews, and smooth ride. You won't be disappointed :friday:
 

rayra

Expedition Leader
aftermarket 'lift' keys. It is not the same, as Matt asserts. You are getting greater resting rotation (and thus unloaded / resting lift) withOUT greater loading of the torsion bars, ergo the ride is a little better, given keeping the same torsion bars.
Matt's also missing that his was a 4000-lb? pickup, with different torsion bars, vs a 6000-lb Sub with the Z-71 suspension package. There are several different torsion bar 'strengths' available in the GMT800 series of trucks / SUVs (at least 6 that I'm aware of). Don't take my word for it, go look it up. And the extra ton of vehicle weight is flat out going to make a suspension move more, when things get going.
And that doesn't even begin to factor in metal fatigue in the torsion bar / springs, in these older vehicles.
All those factors make a big difference in ride comfort and the Z71 Suburban was certainly engineered to ride better than a pickup.
But either factory or lift keys, if you adjust them until your IFS / control arm angle is maxed, you'll get more jounce since you've changed the physics / 'moment arm' geometry of the IFS.

And lastly, it's a 6000-lb SUV on a limited range of motion IFS, It's gonna be lurchy, regardless of what you do. Put some money into better shocks, which won't fatigue on an extended off-road drive.

Talk to GeronRacing / BurbOne about his evolutions, he's been thru every config on his way to an aftermarket coil-over design which he's singing the praises of.
 

Matt_

Observer
aftermarket 'lift' keys. It is not the same, as Matt asserts. You are getting greater resting rotation (and thus unloaded / resting lift) withOUT greater loading of the torsion bars, ergo the ride is a little better, given keeping the same torsion bars.
f.

All this means is you do not understand how torsion bars work. Lift height is a direct function of torsion bar rotation. Lift keys add more pre-load (ie twist) than stock keys. If a rested stock torsion bar is twisted 15 degrees, and 20 degrees at full "crank", and an aftermarket key twists the torsion bar 20 degrees at rest, its still 20 degrees twist, period. The ride and effect on suspension geometry are the same, the only difference is how much pre-load it takes to install the keys, and how far the adjustment bolt sticks out the bottom. It's not rocket science.

Also may want to check those curb weight numbers, you're almost a ton off for a 2005 crew cab 4x4 pickup (you dont even get close to 4k unless its a 2wd RCSB) ;). But that's besides the point, lack of down travel on rough terrain from cranking (even moderately) is the killer.
 
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Bayou Boy

Adventurer
I agree with Matt on the torsion keys.

Yep. Back when I had my 2003 Z71 an easy mod was to buy then current 4wd F150 keys. On the Z71, you'd run out of adjustment before you got any height. The F150 keys were the same dimensions but the hex was keyed just different enough to allow you to actually get an inch and a half or two out of them.

If you are considering just torquing the bars, buy a set of 2003 or thereabouts F150 keys. Cheap and work perfectly.

There's another thread somewhere that asks why you don't see many GM builds on the trails. Torsion bars and the inability to correctly apply small lifts to them is one big reason.
 

Chili

Explorer
I used the Rough Country keys and puck spacers (rear) on my old 2005 Z71 Suburban (their 'leveling kit). The front end is about is high as I wanted to go without destroying the ride. It was right on that line. From what I understood at the time, they were basically the same as the Ford keys that everyone was using.
 

CrazyDrei

Space Monkey
How low budget are you thinking about going with your 300k mile truck?

$0: Factory keys turned a few turns and some trimming gets you 33s without rubbing if you have the Z71 or tow package.

$50: Ford keys with no turns and rear coil spacers get you 33s without rubbing as is. 2" spacers if you have new/heavy duty springs or 3" spacers for old/non heavy duty springs.

$240 gets you a full set of 5100 belsteins.

$120 gets you a full set of el cheappo skyjacker hydro oil shocks that you will replace within 6-12 months.

$350 gets you a 3" body lift that will clear 35s with some trimming or no trimming if you get the ford keys and coils pacers.

$600-1,000 parts only for RC 4-6" suspension lift, no rubbing with 33s minor trimming for 35s.

QUrPlzZ.jpg

Factory ride height with 32.1" tires

bqL0Inu.jpg

$50: Ford keys no crank and 3" rear coil spacers

qdL3T7U.jpg

$340: Ford keys no crank, 3" rear coil spacers, 5100 Bilstein shocks

fniIpcr.jpg

$340: Ford keys no crank, 3" rear coil spacers, 5100 Bilstein shocks, no trimming, 37" tires

uBJKgdA.jpg

$650: Ford keys no crank, 3" rear coil spacers, 5100 Bilstein shocks, 3" body lift, lots of trimming, 37" tires.

Hope this helps!
 
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rayra

Expedition Leader
Shifty98, you can either listen to the guy(s) who have actually done what you want to do, or you can listen to pickup drivers and people shoveling 'common wisdom'.

Here's the factory Z71 key over the Rough Country 'leveler' key. It's akin to the 'Ford' key swap being mentioned.

suspensionlift06.jpg



My installation of that Rough Country kit, my direct experiences and detailed photos are in the early pages of this topic, along with a lot of other problem solvings related to the GMT800 / Vortec vehicles -
http://forum.expeditionportal.com/t...-Guys!-Sierra-pickup-Suburban-Yukon-etc/page2
And several pages later is the second pass at that install when I upped the rear spacer from 3/4" to 2"


Here's the link to the roster of 20+ Suburban / Tahoe owners here who have posted about their mods and choices / experiences. Several of them have done such basic lifts and reported their experiences and most are very willing to answer questions or give useful actual experience with these vehicles.
http://forum.expeditionportal.com/t...ckup-Suburban-Yukon-etc?p=2302987#post2302987


And if you want to do some research farther afield, there's always z71tahoe-suburban.com


oh and I looked again, it's TEN different torsion bar offerings.


bottom line the low-budget 'keys and spacers' lift works great on these vehicles, it's good for at least 2" of suspension height gain without any noticeable decrease in ride quality. That's my direct experience. And I've still got 4-5 full threads of adjustment range remaining on the torsion key bolts. That's about another 1" of ride height adjustment. At which point things get very stiff, you're on the stops, and your CV angle and wheel bearings are going to give you problems.
The downside is that due to the square nature of the wheel well openings on these vehicles, you don't gain much room for larger tires. you can fit 285/70-17 as-is. With maybe a bit of wheel tub rub in the front, turning, under compression. Any bigger tire and you start contacting the fender metal and the front bumper shroud and you'll have to start making relief cuts to enlarge the fender opening.
If you want to see the far end of the 'big tire in a Suburban' spectrum, go read about the damage and problems (and fun shenanigans) in CrazyDREI's Suburban topic.

eta - hah, 'speak of the Devil and he shall appear' Drei got in while I was pulling links together.
 

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