Home Forums Gear Hunting Trucks and Four-Wheel Drives Toughts on putting in a 2" - 2.5" lift kit

I'm starting to give some thought about putting a 2" or 2.5" lift kit on my GMC 2500HD quad cab short bed 4x4 to give me just a little extra ground clearance. This past fall was the first time I took it hunting and it bottomed out in places where my old 3/4T suburban didn't. What are your thoughts or experience on this?

I am in the same boat and have done a bunch of research on how to get bigger tires under the truck. First off, I don't think they make such a thing as a "proper" 2"-2.5" lift. Most are variations on leveling kits where you crank the keys up.

If you have a newer truck, you probably don't even need to get new keys, you can just crank yours up. All the BS the aftermarket key makers feed you is just that, BS. If you can get the lift you want from your stock keys, there is no need for their aftermarket keys.

They typically package these with nothing else and sell it as a leveling kit, or with a short block for the rear as a 2"-2.5" lift. No matter how you cut it, cranking the keys all the way up isn't good for the truck. The first thing you need to do is buy longer shocks or get shock extensions, or it will ride really, really bad. Once you do that it just rides really bad, instead of really, really bad. You have to get an alignment after a key crank, and sometimes they cannot get everything to spec if you crank a lot.

Then, your ball joints on your upper control arms are pushed all out of their proper alignment, leading to premature wear. You can fix this by buying aftermarket UCA's from someone like Cognito.

If all this isn't bad enough, the fatal flaw in the whole torsion bar lift is the CV angles. No mater what you do, if you are getting 2.5" of lift from cranking the keys, your CV's will be at awful angles (they should be nearly level). This wears them really fast and they can bind and snap in 4 wheel drive. You can probably go up in the front about an inch before you start to run into troubles. It just depends on how your truck is setup now and what you feel you can live with.

Since you say you want this lift because you go off-road, I assume a functioning 4 wheel drive system is important to you. I believe you will be much happier in the long run if you pony up for a proper 4" or bigger lift and set it so the CV's are at the proper angles. A non torsion bar drop lift (NTBD lift) will keep the bars tucked up under the truck.

As you probably know, the whole point of a lift is to put bigger tires under the truck, as they are what really gives you clearance. Even with a lift, you are probably going to have to do a fender modification to get them to fit, especially if you run 35x12.5's. It is easier to fit a big tire under a truck with stock wheels than aftermarket a, as the aftermarket wheels typically stick out further and exacerbate rubbing.

If I were you I would start with the following.
1. Google "2500hd level green zone" to learn about how far you can go by cranking keys.
2. Google "nor cal nick small fender mod" and "nor cal nick large fender mod" to learn what level of cutting and hammering it takes to fit the tires you want under your truck.
3. Try a small crank and fender mod first. Just don't crank the keys past the green zone. Most good tire shops will do a test fit to see if your tire choice rubs.
4. If you are unhappy with the results, go with a 4 inch lift. You need the fender mod anyway, so you didn't spend a dime trying out the key crank.

Or just screw it all and buy a Jeep and a trailer to haul it on. Good luck!

Thanks for all the info! That opens up a whole new realm for me. I'm not interested in bigger tires although I'm sure they'd help. With the longer wheelbase of the quad cab, I find I'm dragging my belly on the same old two tracks where the suburban didn't. I figured a 2 inches give or take would take care of that. Looks like I have a lot more research to do. Thanks again!

No problem. What year/model/tire size do you have? A lift will help you since you are dragging in the middle rather than the axles. I would not be afraid to crank the front just a bit, but chances are it won't be enough to really help you out.

Just do some research and remember my opinion is worth what you paid for it. I tend to be pretty conservative when it comes to messing around with the suspension on an expensive new truck. Some guys crank away with no worries, and hammer and saw to get stuff to fit. Sometimes I wish I had their attitude, as they seem to have fun.

If you want to raise the suspension/frame you need to run bigger tires.

That's kind what I was suggesting. The only way to get more clearance EVERYWHERE is bigger tires, which means you probably need a lift to get them on. New stock 2500hd's run 32.5's. Switching to 35's gets you 1.25" more ground clearance.

You don't need a "key" to get a 2" lift. You get a leveling kit...no key involved, easier on your driveline angles.

You can probably put 33" tires on it without doing anything, but you won't get much clearance.

A 2" leveling kit on a 3/4 ton will most likely get you 35" tires. You may need to trim some plastic to prevent tire rub though, not really a big deal if you take your time and make it look nice.

By the time you pay for the lift and larger tires, you might as well buy a UTV and be done with it.

All I did was crank up the torsion bars on my 2001 K2500hd, I was able to put 285/75/16s on it.

If you are going to do it, check out the Cognito kit. mtmuley

Crank the torsion bars up one inch, add a longer shackle on the rear springs and put a two inch body lift on it.

Before you do anything, get the truck "crossed up" in a ditch so that it'll teeter on one front and one rear wheel. This will enable you to get out and look and determine exactly how much clearance you actually have with your current tires.

Next you need to actually measure the height of the tires you intend to install. This will allow you to calculate the amount of lift you need. I would put 33's on it and call it good. 35's will require numerically higher ring and pinions, anyone who says different is FOS, unless the truck came from the factory with some sort of low-geared tow package, which I seriously doubt. EVERY increase in tire size increases the likelyhood of driveline failure off road, IE, U-joint/CV, output shaft etc. You want enough tire and no more.

Also, if you determine that sheet metal/fender is the limitation, have at it with a sawsall and install plastic fender flares.

Adding a lift kit won't do anything for more ground clearance for the axles and diffs., but it will help alot to improve your breakover angle, which I've found to be alot more a problem than any 1-3 inch increase in ground clearance will help.
Yes, one needs to understand that going to larger tires can easily add more to alot more stress on the key components of the truck. It can also depress the vehicle's ability to pull at low speeds when off road. Not good when you are trying to climb a steep grade on a chewed up road. So, if you are buying a new truck, you want to plan ahead and order axle ratios in the 4's if possible.
As a rule, adding only 2-2.5 inches of lift usually doesn't require many modifiactions on other components. But each vehicle is different. What I'd do is talk to those who do such things for a living and do a complete package when lifting an off road vehicle. E

What year truck? I'm thinking similar for my suburban..

It's a 2005. I'm going to check with the dealer I bought it from. The are an independent garage but the owner's dad was a GMC dealer so he knows his way around the trucks.

The bugger of getting more ground clearance is it requires larger dia tires more than anything else, which is what pushes you to get the lift kit. But once you get larger dia tires, you've effectively changed your gear ratio. If you want the same gear ratio, you need to crack open both differentials to regear. While you have the differentials opened up, you might as well go with a locker. And then you start thinking, well if I'm going to all the trouble of doing a proper lift, I might as well go with big enough tires to make it worth while, and then you start looking at break upgrades, and adding some hp...

It's a slippery slope that can get real expensive fast.

This.

Quite true, but a modern V-8 truck can do just fine with a slightly larger tire. Braking distance WILL increase though, so one should drive accordingly.

We all have to deal with the Z-71 Dickhead sporting 35's who drives it like its a Mustang GT and rides your bumper like the azzwipe he is. Totally clueless that his braking distance has doubled, and he can't understand why his SB chevy is now gutless. Hell, he probably posts here.

lol.

He's trying not to scrape the bottom of the 'burb on the trail, not jump cars.

Put a leveling kit and 33-34's on and you'll be fine. If you're going to go with 35's, you'll probably need a 3-4" lift. Then you can start to dig into the diff's.

The only thing I'll add is you'll be dissappointed with less than 4" of lift.

Oh wait, one more thing or two. The skinnier tall tires will rub less and get you ground clearance. Wide tires are harder to fit without rubbing but work better in sand. skiny's are great for digging deeper in snow and mud if it has a bottom, otherwise wider works.
Lift and big tires don't do diddly squat without traction. If you don't have at least a limited slip you may find yourself frustrated. I would suggest a locker in the back, limited slip or selectable locker in the front.

Yuh huh.

Did a 2.5" on my Expedition (open diffs) and stuck some 34" Mud Terrain KM2's under it.

It's the most WORTHLESS, HELPLESS P.O.S. I have ever had off-road. I joked with my brother when he retired his Trailblazer and bought an Equinox. But I think the Equinox would go anywhere my lifted "off road" SUV will go.

Tahoe Z-71 coming up !!

Prayers sent.

Save 'em for somebody in need.

Momma's got a stock height Z-71 'Burban on BFG MT TA Km's that is 10X the off-road vehicle the Expedition is in every respect except possibly inside storage.......... which don't mean chit when you're stuck in 4 inches of mud.

The truck has the eaton locking rear diff. so that part of it's covered.

I had one in 04. It was the biggest POS I (we) have ever had. Motor was fine, the rest of the rig was chit. Poor fuel mileage, much lower than advertised, trans leaked like a sieve, trans cooler lines broke, front diff gernaded, TONS of electrical problems, including the those that are now in the news. Ignigion chit out and couldn't put the vehicle in gear. Computer board that ran the dash went out 3 times!!! Most was under the factory but, it was the first vehicle I bought and extended warranty for and man did I get my money's worth from that!

Wow.................

I guess you got GM's equivalent to my Expedition.

Just goes to show that somebody, SOMEWHERE will end up with that ONE built at the end of Friday's shift.

The funny (or not) thing is, a lot of it is what is being recalled by GM right now. But, the 04 Tahoe isn't on the list.