[Backwoodssob]

Okay guys I am in need of some advice. I installed a 3" strut spacer lift, and a 2.5" block kit in the rear. I also had the alignment done the very next morning. Truck looks damn nice like this. However now when I am accelerating between 20-40 MPH and when I am slowing down at any speed I get a vibration thru the whole truck. Like a seat vibrator type vibration. I t drives straight and doesn't pull at all any direction accelerates good and brakes good. Just has that vibration at times. I did order a differential drop kit, sway bar drop kit, and rear leaf shim 2.5 degree kit. I will have all of that installed by the end of the week hopefully and let you know if that changes it I'll let you know.

 

[mrbones]

I have installed the rough country leveling kit with 2in spacers and have no issues. Might point you to the rear

 

[Backwoodssob]

I have installed the rough country leveling kit with 2in spacers and have no issues. Might point you to the rear

Yeah I'm hoping the rear shims will do the trick. Tank you.

 

[Skrow]

Might need to check your drivetrain? Does the lift change the pinion angle. Not too familiar with trucks, but I am familiar with lifting Jeep Wranglers. On Jeeps if you get over 3" of lift, you can get vibrations from the angle of the driveshaft being too steep vs. the pinion angle. Just a thought, like I said, I'm not well versed on truck lifts.

Otherwise, truck looks real good with the lift on it.

 

[Backwoodssob]

Might need to check your drivetrain? Does the lift change the pinion angle. Not too familiar with trucks, but I am familiar with lifting Jeep Wranglers. On Jeeps if you get over 3" of lift, you can get vibrations from the angle of the driveshaft being too steep vs. the pinion angle. Just a thought, like I said, I'm not well versed on truck lifts.

Otherwise, truck looks real good with the lift on it.

I appreciate the thought. And I am more and more convinced it is in fact the rear drive shaft. I just put the diff drop in which was 1.25", and the 1" sway bar drop and it didn't help. So I am hoping to get the rear axle shims in tonight and installed. I'll let you guys know.

 

[Backwoodssob]

Okay guys here it is. Great news, the vibration is gone. It was in fact the angle of the rear axle. I started with a 2 degree shim but it still had a slight vibration so I went to a 4 degree shim and it's gone. So advice... if you go with blocks you will need shims or relocate the mounts. If you go with the shackle drop I would GUESS you should be fine. I just prefer blocks over shackles. Thanks for the input guys, I really appreciated it.

 

[Skrow]

Glad to hear you were able to resolve your issue. I'll have to hit up Google to see exactly what you did for my own personal knowledge.

 

[Rockcrawlerdude]

Did you need to angle the pinion up or down?
I have an add a leaf and a 1" block (2.25" total) and haven't had any issues on my crew cab short bed

 

[Backwoodssob]

Did you need to angle the pinion up or down?
I have an add a leaf and a 1" block (2.25" total) and haven't had any issues on my crew cab short bed

I had to put a 4 degree shim in the rear shifting the front up.

 

[Rockcrawlerdude]

I had to put a 4 degree shim in the rear shifting the front up.

Thanks. Glad you got it sorted out. Only issue I am having is topping out my rear shocks (they're a little too short now) very clunky when it happens.

 

[Backwoodssob]

Thanks. Glad you got it sorted out. Only issue I am having is topping out my rear shocks (they're a little too short now) very clunky when it happens.

I got lucky, I did an upgrade on a 2015 highcountry a year ago, swapped with off road shocks and never threw the OEM shocks away. They were a perfect fit.

 

[Skrow]

Thanks. Glad you got it sorted out. Only issue I am having is topping out my rear shocks (they're a little too short now) very clunky when it happens.

I would imagine you will need some taller shocks with that 2.25" height increase. Did you also lift the front?

 

[Backwoodssob]

I would imagine you will need some taller shocks with that 2.25" height increase. Did you also lift the front?

The OEM 1/2 ton high country shocks were taller that I replaced my OEM with.

 

[Rockcrawlerdude]

I would imagine you will need some taller shocks with that 2.25" height increase. Did you also lift the front?

Yes also lifted in the front, getting longer rear shocks soon.

 

[Rockcrawlerdude]

The OEM 1/2 ton high country shocks were taller that I replaced my OEM with.

Would you mind measuring the static height of your shocks eye to eye?

 

[Backwoodssob]

Would you mind measuring the static height of your shocks eye to eye?

I will and get back to you.

 

[AndyZ71]

glad you got it figured out. I had an old Jeep XJ that I did a 3" lift on with a new leaf pack and had a hell of a time with vibration problems. It sucks when there are so many possible causes, all those parts start to add up fast when they don't fix the problem you're chasing.

 

[Backwoodssob]

glad you got it figured out. I had an old Jeep XJ that I did a 3" lift on with a new leaf pack and had a hell of a time with vibration problems. It sucks when there are so many possible causes, all those parts start to add up fast when they don't fix the problem you're chasing.

Very true.

 

[Fredncarm]

I appreciate the thought. And I am more and more convinced it is in fact the rear drive shaft. I just put the diff drop in which was 1.25", and the 1" sway bar drop and it didn't help. So I am hoping to get the rear axle shims in tonight and installed. I'll let you guys know.

How did you do the shim? We raise ours 5 inches in all and the vibration is getting worse and worse

 

[Rockcrawlerdude]

How did you do the shim? We raise ours 5 inches in all and the vibration is getting worse and worse

Angle shims install between the axle spring perch and the leaf springs. These can be used to correct driveshaft angle issues. U-joints need to be run at the correct angle to balance out the acceleration and deceleration phases of the upper and lower u-joints.

The real question is what did you guys do with your rear brake lines? they’re maxed out at 2” lift