Peak Lift Issues

[glossner2001]

I just installed the Peak 2.25 inch lift, 1 inch rear block, and Cognito UCA on my ZR2. When driving on the high way, I can feel a vibration in both the steering wheel and the pedals. What could this be? I've attached my alignment specs. Does anything look off to you guys? Everything is torqued down to specs so not sure what else it could be. I'm also getting some hub centric rings for my method wheels which have a hub bore size of 108mm compared to 78.1mm for our trucks. Maybe that is causing the vibration? I didn't feel it prior to the lift so not really sure.

 

[MrScottly]

Vibrations are not usually suspension, but rather tire and wheel. You have a lot going on here and it appears some information left out. So, some questions: Did you put the lift on and use the same wheel/tire you were using BEFORE the lift...then driving it and noticing the issue? Did you put on different wheels and tires AFTER the lift (the Methods) drive it and notice the issue?

 

[glossner2001]

Vibrations are not usually suspension, but rather tire and wheel. You have a lot going on here and it appears some information left out. So, some questions: Did you put the lift on and use the same wheel/tire you were using BEFORE the lift...then driving it and noticing the issue? Did you put on different wheels and tires AFTER the lift (the Methods) drive it and notice the issue?

Yes, I used the same wheels and tires that were on prior to putting the lift on. I never noticed any issues before.

 

[MrScottly]

Rotate the tires and see if the vibration relocates.

 

[glossner2001]

Rotate the tires and see if the vibration relocates.

I'm going to try that along with installing the hub centric rings today. Will report back the results.

 

[GATORB8]

If it's speed dependent (like 45 mph +) it's likely balance. Could have simply popped off a stick on weight.

Hub centric rings have never actually been an answer for a vibration issue for me.

 

[glossner2001]

If it's speed dependent (like 45 mph +) it's likely balance. Could have simply popped off a stick on weight.

Hub centric rings have never actually been an answer for a vibration issue for me.

Yea its definitely 65 MPH +

 

[GATORB8]

Yea its definitely 65 MPH +

First thing I'd do would be a rotate/balance, cheap and may as well have it done anyway.

If you are running in 4Auto try 2 Hi. I'm not positive how the front end axle disconnects work, but that should at least rule out front driveshaft and maybe CV angles. Normally those will change intensity with speed, but not be speed dependent.

 

[AXE]

I just installed the Peak 2.25 inch lift, 1 inch rear block, and Cognito UCA on my ZR2. When driving on the high way, I can feel a vibration in both the steering wheel and the pedals. What could this be? I've attached my alignment specs. Does anything look off to you guys? Everything is torqued down to specs so not sure what else it could be. I'm also getting some hub centric rings for my method wheels which have a hub bore size of 108mm compared to 78.1mm for our trucks. Maybe that is causing the vibration? I didn't feel it prior to the lift so not really sure.

Lots of arm waving going on here about balancing. If they were balanceed before they are balanced now.

You changed the entire geometry of the front end and I can guarantee your feeling that because it isn't set up right. I would find out who your local lift shop uses for their alignments. Aligning to specs after lifting is like pissing in the wind. I take mine to a couple shops that do this stuff by measuring like the old school guys did. Much better feel and handling that way!

 

[GATORB8]

Lots of arm waving going on here about balancing. If they were balanceed before they are balanced now.

You changed the entire geometry of the front end and I can guarantee your feeling that because it isn't set up right. I would find out who your local lift shop uses for their alignments. Aligning to specs after lifting is like pissing in the wind. I take mine to a couple shops that do this stuff by measuring like the old school guys did. Much better feel and handling that way!

What do you think is wrong with the alignment? He’s in spec except for camber and that’s likely because he’s down 2.5” in the control arm arch and there isn’t enough adjustment to get it back. The alignment tech put his toe back in spec.

There are definitely ride changes you can dial in with alignment, but, in my experience, speed dependent vibration isn’t one of them. Balance and bolt torque checks is first since it’s cheapest and easiest. Then it’s time to hunt bad bushings/connections.

 

[AXE]

What do you think is wrong with the alignment? He’s in spec except for camber and that’s likely because he’s down 2.5” in the control arm arch and there isn’t enough adjustment to get it back. The alignment tech put his toe back in spec.

There are definitely ride changes you can dial in with alignment, but, in my experience, speed dependent vibration isn’t one of them. Balance and bolt torque checks is first since it’s cheapest and easiest. Then it’s time to hunt bad bushings/connections.

You can't align to standard specs, because the specs changed. Take it to someone that knows how to align a lifted truck and problem solved.

Mine was "in spec" right after I installed 295s. Difference is i knew it wasn't handling right, so.i had them make an adjustment.........donzo.......drives like a champ.

His truck is only a few months old, it ain't worn parts, it's the geometry. I was pretty good at maths, especially geometry.

 

[Nmass94]

May be the rear blocks-
When you add blocks you do two things
1- mess with driveshaft angles (which need to be roughly the same but opposite at the t case and the pinion)
2- increase the effect/ severity of axle wrap by increasing the moment arm between the fulcrum and where the force is applied.

Some lift blocks have a taper to adjust the pinion angle to combat this, and can cause issues if installed backwards.
However I think the peak blocks are square.

The reason it happens at high speed is because you're applying more wrap force to the leafs.
If you ease of the accelerator and coast does it lessen or dissapear?
What about hard acceleration from a stop? That will usually also cause vibration if your driveshaft angles are off.

 

[glossner2001]

May be the rear blocks-
When you add blocks you do two things
1- mess with driveshaft angles (which need to be roughly the same but opposite at the t case and the pinion)
2- increase the effect/ severity of axle wrap by increasing the moment arm between the fulcrum and where the force is applied.

Some lift blocks have a taper to adjust the pinion angle to combat this, and can cause issues if installed backwards.
However I think the peak blocks are square.

The reason it happens at high speed is because you're applying more wrap force to the leafs.
If you ease of the accelerator and coast does it lessen or dissapear?
What about hard acceleration from a stop? That will usually also cause vibration if your driveshaft angles are off.

Yea I used peak blocks and they are square.

 

[glossner2001]

Well, rotating tires and hub rings did not fix it. Has to be the alignment.

 

[MrScottly]

Well, rotating tires and hub rings did not fix it. Has to be the alignment.

I don't believe that. Let us know what happens after you get it aligned.

 

[glossner2001]

I don't believe that. Let us know what happens after you get it aligned.

what do you think it is?

 

[MrScottly]

what do you think it is?

Without looking at the truck and the work that was actually done, I'm only guessing...And guessing from my own personal experiences....So here goes: A vibration is something moving at a given frequency - Tire out of balance/out of round is moving up and down, driveshaft out of balance/out of round is moving up and down, or binding, etc. You can narrow those down to location of the vibration.
But, the only thing an alignment does is set the position of the wheels in relation to the centerline of the chassis. Theoretically, if there is no wear in any of the steering parts, the wheels will rotate on the axle with no upward or downward movement, no matter if the wheel is canted outward/inward along the centerline(camber), turned toward/away from that centerline (toe), or leading/trailing the axle centerline (caster). On an independent suspension vehicle, total toe is not normally zero as this helps to stabilize the wheels from shimmy...Positive caster forces the wheels to point forward. Your total toe is positive and your caster is positive and balanced, so that thing should steer easy, return to center after a turn, and not shimmy(positive toe).

ASSUMING ( I hate that word) that you are absolutely, positively sure your tires were not doing this prior, then what changed? A) The rear driveshaft angle...That'll cause issues if it's too steep. B) The front shaft angles... Your vibration is in the steering and pedals...Kinda points to that. Using a spacer kit to drop the differential would solve for it. C) Damage to driveshaft when it was put on the rack...a little ding will do 'er.

These are my best guesses, and that's all they are.