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Rough Country 2.5" lift

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14K views 10 replies 5 participants last post by  08Canyon  
#1 ·
Hey guys I'm doing my first lift on my first truck. 05 Chevy Colorado ext cab 3.5L Z71 4wd. I'm adding the 2.5" lift from rough country, 2.75" rear shackles and front 2.5" torsion bar/ key spacers.

Yes, I have searched.

Question.

Do I need to extend my front and rear brake lines?

Do I need to get longer bolts for the torsion bar keys, since I intend on putting a 2.5" spacer in there?

Do I need to get new shock with an extended length? I'm going to replace them at a later date. The truck has 178,000 miles on the inline 5.

I know I need to realign the front suspension, but do I need to have the rear done too??

Pictures of before and after to come.

Thanks guys!
Kris
 
#2 ·
No brake line modifications. With exception.....the bracket for the rear is mounted to the rear diff. If you go 2" or more the metal line will be a bit tight. That line should be spaced up, or maybe bend the bracket to alleviate some stress.

Longer shocks in the rear on 2" or more. 2" is acceptable for road use, but off road and any type of suspension flex and you're risking damage.

No, you don't need longer bolts for the spacers. But you can try to raise the front after you do the work to the rear. You might find that the spacers are unnecessary for your truck. Unlikely, but possible.

You are not installing 2.5" spacers. The spacers are very small. The lift is achieved by turning up the torsion bar. Not sure the exact description, but think of it like turning up the tension. But you really aren't changing tension. Thats why you may not need to use spacers. You may be able to achieve the desired lift on stock keys alone.

Also, after you are happy with the stance side to side and front to back, drive it to allow it to settle. Measure and tweak as necessary. Once it's final, make sure you have not exceeded 24.5" from center of hub to lip of fender. Bad stuff starts to happen beyond there.

You should read up on lowering your front differential too.
 
#3 ·
I need to lower the differential on a small 2.5" lift?

Here's the link just in case
Chevy/GMC Colorado Suspension Lift Kit

What kind of bad things can happen is I turn the key to high? I read on here. If you draw a line on the bolt and mount and count the turns is a good way to do it. I'm planning on 7-8 turns.

I do plan on adding new shocks, and new 2" or 3" keys, maybe a body lift.
 
#4 ·
Lowering the diff depends on how sagged you are now relative to where you will be after you crank your tbars. Look at your CV shaft's and if they are at a decent angle downwards, then you need to drop your diff. Your shafts should be relatively close to level, a slight downward angle, when the truck is sitting level on the ground.

The new keys only help compensate for old sagged out torsion bars. Before you get new keys, I would look into getting new torsion bars. Since you are 05, new tbars would probably give you a solid lift by themselves (which would really only get you back to stock, but then you could crank from there and not need new keys)
 
#6 · (Edited)
A small 2.5" lift isn't a very accurate statement. You can lift to about 3" (some go more). So you are going about 1/2" from max lift. Lowering the differential is importnat. You mght consider just lowering the differential by about 1/2". That can be achieved by stacking washers. Purchase as many 14mm (I.D.) washers as is required to equal 1/2" thick. There are 4 mounting locations.

As mentioned above, a before/after comparison is a good idea. The axles should be relatively level. When you lift it determine if it is not level then lower accordingly. The most commonly used is a SuspensionMaxx part including 4-3/4" spacers to insert between the mounting flanges of the differential and the frame.

Should you not do the differential lowering, two of the concerns is tearing the CV boots, and destruction of the CV Joints themselves. When the axle angle is indeed an angle, the boot is compressed (like an accordion) and over time the boot rubs on itself and wears holes in the rubber. Once there are holes worn in, the grease from inside gets spun out during rotation. When there is no grease then the CV's run dry eventually wearing out. Unrelated to grease/boots, if the CV's are put under too much pressure during offroad use, you'll end up breaking one (or both).

Other concerns with max lifts (you aren't lifting max) are Upper Control Arm (UCA) that crack. Ball joints that wear out prematurely. And alignment issues. The cam adjusters can only take up so much adjustment. It is highly unlikely you will have ball joint, UCA or alignment issues with the spacers installed though.

Counting the number of turns is a good starting point, with stock keys and no spacers. You have to remove the bolts to insert the spacers. You CAN count the turns required to remove, then turn the same amount, however at that point you will be lifted higher because the spacers have tricked it. It's just time consuming to do that in your example. Should you elect to count, just put a mark on the bolt head. You are probably going to be turning in 1/4-turn increments and have to get a new bite each time with your breaker bar. So you can easily see how many times you've turned the bolt.

I can't believe I'm writing this all over again. haha Jack up the vehicle and support the frame with a jack stand. Unweight the suspension components with your jack (don't allow full droop) so the torsion bars are unweighted. Remove the bolts for the keys. Insert your spacers. Thread in the bolts. If I had to guess, you are going to have to turn in the bolts almost all the way to achieve the lift you are after.

Since you are adding spacers now, there is no need to add any keys in the future. You're doing the same thing with the spacers.

Eagleknight is correct about the torsion bars. They can be purchased from GM Parts Direct for I think about $50/ea. That's at least as cheap as the cheapest keys you can find. The labor to replace bars vs. keys is nearly identical. Folks on new trucks get at least 3" of crank on their truck with no keys. Should you find the spacers haven't given you adequate lift to match the 2" raised rear you might consider bars. Otherwise, installing the shackles and spacers is a quick and simple approach.

All of this information is partially usable because no matter the method you choose, you don't want the hub/fender to be greater than what I previously mentioned. It doesn't matter how you get there, the final results are the same.

I know I know, there is a tone of blah blah blah in here. You can just install shackles and spacers and lay your seat back and drive what looks like a more cool truck, but it's nice to know how to keep the cool truck operational for years to come.
My apologies for such a lengthy post, but I didn't actually say anything that you shouldn't know.
 
#8 ·
Any right up on dropping the diff 1/2" or so? How hard is it? I'm a newb in lifting trucks. I've slammed a few vws before. And I do have air tools.

I'm on a limited income right now. Disabled paramedic here.

Can I use 1" hockey pucks to use as spacers to lower the diff?! Do I need longer bolts?! If I add any type of spacer?
 
#9 ·
I'm not sure if there are any writeups on that or not. A hockey puck would be too large outside diameter. I think you are referring like a body lift hockey puck?

There are 4 bolt that hold the differential up. Two on each side of the vehicle. They are both mounted vertically. You can see them when you lay under the truck. You can do two together, one side. Support the differential or axle with your floor jack. Locate the two bolts. Loosen the bolts then slowly lower the differential until there is a gap between that and the frame. I actually pulled the bolts and took them to a wire wheel to make them clean, then spray with brake cleaner just to be sure I didn't contaminate them with any residue from the wheel. The only reason I did that step is because I used blue Loctite on the threads. Run the bolts up and repeat for the other side.

You don't need new bolts. It's been said by Larry at Suspension Maxx (who sells 3/4" and 1 1/4" spacers) that 3/4" spacers are fine with stock bolts but he sells longer bolts for the 1 1/4" spacer. Some on here have spaced an inch or maybe more on stock bolts.

It's actually pretty easy to do. What you might find to be a good idea in advance is to try to remove one bolt at a time (no jack necessary for this) to make sure the bolt comes out. There is a captured nut in the frame and some have had that weld break so the nut just spins. If you take one bolt out at a time, nothing will fall out or anything. When you have successfully removed all 4 individually you can proceed with spacer installation how I mentioned above.

Also, no air tools required. I don't remember the size of the head, maybe 18mm. The bolts are 14mm threaded. You might find yourself needed a couple different extensions. The longer the better because I think one of them are at a tough angle.

I have a picture of something under my truck and the spacer I have is visible. Let me see if I can find it. Also I'll check another thread on installing keys to see if they discuss the differential. I won't go look for that one unless you want more information.
 
#11 ·
Here is the picture I was looking for. The picture is not for this purpose, but you can see off to the right a silver little spacer thing. There is a sticker on it that says "MAXX". Below that is the black bushing that is stock. This photo is taken of the driver side looking forward. Now that you can visualize that spacer, look almost directly to the left a little bit (which is forward in the truck) and just to the right of the shock. You'll see the other spacer. Those are the two for the left side.

Hope the pic helps.
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