Mild Vibration after level kit, shocks, and new tires - help

Ezekiel2517 · October 25, 2016

I recently added a 1.5" motofab level kit, along with Bilstein 4600s, and Nitto Terrra Grappler G2 275/60/R20s (33"). I did them all at the same time, basically within a week.

I immediately had issues with my rack and pinion making a clicking sound. It was replaced by the dealer, but no they must have not checked it out because now I have to take it back for a slight pop it makes when I turn the wheel toward full turn.

When I hit 60+ mph I notice a slight vibration or shimmy that I cant seem to pinpoint. I have had the tires balanced twice, and one of those was a road force balance. The feeling is almost like that of a slight bad spot on a tire. It is has a frequency like that if that makes any sense. High frequency but not continuous. I had them rotated and could not tell a significant difference though. It does not shake the steering wheel visibly but I can feel the vibration. I can feel it through the pedal too just a bit. It is somewhat fatiguing to drive.

I only got up to speed once in the week before I had my rotation and changed the tires. I recall that I noticed this shimmy then, but at the time I figured maybe I just needed an alignment. On my old set of tires I always thought I had a bad spot on one of them similar to this feeling as well. It was and still is now most noticeable on ultra-smooth hotmix roads.

Does anyone have any ideas what I could check? If it was a tire, the only way I think I could find it is to take them off one at a time and try the spare.

Could it have anything to do with the level kit or shocks installation? I am not too confident in the installation of the shocks into the coil overs cuz the shop I used to press them was kinda shady. Im not sure if you can screw that up or not.

Could there be any other condition that could cause it? A wheel bearing? That would seem highly unlikely through.

Any ideas on what top check would be helpful. Thanks for your help.

groutguy · October 26, 2016

Check the top shock nut.

A lot of times it doesn't get tightened up properly, as a special wrench is needed to keep the shaft from turning.

silveradosid · October 26, 2016

do you know what the torque is and would this give a virbation that is pulsating

groutguy · October 27, 2016

do you know what the torque is and would this give a virbation that is pulsating

Each manufacturer is different, but 32 ft.lbs should be close.

If you open the hood and jump up and down on the tow hook, you'll be able to see and hear if the top shock nut is loose.

Dnt · October 27, 2016

Pull the driveshaft and have it professionally trued and balanced. Let us ALL know if that fixes it please...... there is a fella over on the vibration thread that swears by that fix but they treat him like he has leprosy over there and I think he might be onto something, just need someone to verify the driveshaft fix "Tag you are it"

Ezekiel2517 · October 27, 2016

I have been wondering about that top shock nut. I am almost positive that those jacklegs at that shop did not torque to any specs at all.

One shock has about 1/4" of threads showing, the other has about 3/4" threads showing. Ironically the one that has less threads showing is on the side that has about 3/8" less lift than the other.

Anyway, I tried to loosen the one nut to even them out at least. But as I loosened it, the shock shaft did not retract into the shock. It just stayed there an the plate on top rattled loosely. So I tightened it back up till I figured out what the heck. I thought the shaft would suck back into the shock if the nut was loosened.

So big question: if these shocks are set wrong:

1. can the torque be accurately set once they are installed on the vehicle?

2. Can in improper shock nut torque cause a vibration?

Thanks!!!

Brianibew · October 27, 2016

The top stud is stationary and will not retract when you loosen the nut. To properly torque the nut, the spring needs to be compressed so there is no spring load on the shock, so to answer your question, it cannot be properly torqued when it's already installed on the vehicle.

groutguy · October 28, 2016

The spring doesn't need to be compressed if the shock and spring is already installed in the truck. The problem is preventing the shock shaft from turning while tightening the shock nut.

There is a special tool for holding the shaft while tightening the nut. If you do not have the tool it can also be done using a ratchet wrench to tighten the nut while holding the shaft with a bolt extractor socket.

The bilstein 5100 shocks that I installed on my daughters truck, have approximately 1 inch of thread showing, and were torqued to 28 ft.lbs.

Ezekiel2517 · October 28, 2016

Thanks. I'm not understanding why a special tool is needed to hold the shaft. I pair of vice grips on the top flat part of the shaft above the threads seems to work just fine. I assume a very small open end wrench would do the same. Am I missing something here?

blackout07 · October 28, 2016

Re-torque everything. I had a slight popping not too long ago and found my sway bar was loose. Do that before you spend any money.

Brianibew · October 28, 2016

With the shock installed into the spring and fully assembled, installed on the vehicle, there is no way you can properly torque that top nut. The spring has to be compressed and not putting any load on the shock body in order to torque it. Sure, you can tighten the nut with it installed, but it won't be torqued properly. Also, that nut on Bilsteins require a very small amount of torque.

Ezekiel2517 · October 28, 2016

Sorry for my ignorance but I cannot envision this. If you compress the spring enough so that this stem sticks out, then screw the bolt down, what are you torquing against? There would be not consistency on how much the spring is compressed to do this with any accuracy. It almost seems like the only way to torque it would be to compress the spring, put on the nut to get full thread engagement, then release the spring compression, then torque against that spring force. Otherwise nothing is pressing on the nut to stop it to give consistent torque when it is set. But as soon as it goes on the vehicle then that is all shot because the truck compresses the spring some.

Or what else am I missing? Something has to provide the resistance when it is getting torqued.

What is the consequence of over or under torque. I assume that undertoque would lead to slop and rattle maybe? Over torque might make the shock too stiff?

groutguy · October 29, 2016

when the suspension unloads on bumps (fully extended), a loose shock nut allows the shock absorber to drop down by the same amount of clearance that is created by the loose nut. When the suspension reloads (begins to compress), the shock then "pops" back into place and re-seats itself at the upper mount.

If the shock is allowed to constantly move within the mount, it will eventually wear a hole either in the mount or on the top of the shock tube.

The reason there is an oval shape on the shock absorber shaft is to allow for a special adapter socket on the shaft.

You put an open end wrench over the nut, install the socket on the shaft, and using a torque wrench rotate the shaft counter clockwise until the proper torque is achieved. The torque for the shock nut will vary from 18 to 32 ft.lbs. based on the amount of minimal spring compression that is required for that particular application.

The torquing of the top nut is typically done off the vehicle, but can be accomplished after the shock assembly has been installed; it's just a little more difficult to access.

The spring does not need to be compressed except when first installing the nut. Tightening the nut on the shaft to its proper torque is what pre-loads the spring.

You can test to see if the shock nut has been adequately torqued by quickly loading and unloading th front suspension. This can be achieved by standing on the front tow hook applying weight onto the hook jumping up and quickly reapplying your weight. You will hear and physically see the shock shaft move within the mount.

Many times you will also hear a loose top shock nut "pop" when backing down a curb with your wheels slightly turned.

Ezekiel2517 · October 31, 2016

Thanks for the reply. When I get it back from the dealer for the "pop" I will check this out. In the meantime I am really enjoying the glass smooth ride of the 2wd loaner they gave me!

Ezekiel2517 · November 17, 2016

So, I noticed that the plastic seat that the shock sits in is cracked. Not sure what it is called but it sits in on that metal ring perch that the spring then sits on . I wonder if this could be causing my noise? I wonder how that became cracked. Could these new shocks be putting too much force back on them? Should they not even be there with the new shocks?