Stupid vibrations

Sinister16

New member
So i kinda messed up I did everything that I could at the same time lift, steering upgrade, rims and tires
Now I have a vibration starts at about 50 and really kicks up at 80 first I thought tires. Changed them around and no change. I thought front pinion angle so I took out the front drive shaft and no change. Took the tire weights off and put in beads no change. Out of ides what could it be.
 

Sinister16

New member
Here is all the stats on my jeep
16 JKU Rubicon
4" Teraflex RT long arm
Teraflex high steer heavy duty steering
35-11.5- 20 tires
Smittybilt front and rear bumpers
Smittybilt 12k winch Factor 55 flat link
Teraflex tire carrier
Rough country MLC 6 switch pod
Orical rock lights
MSD ignition Coils
 
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wjtstudios

Hooked
What brand if tires. Most vibrations like that are either tires that aren’t balanced properly or a driveshaft issue. I’d start with the tires. It may take 2-3 times to get them balanced right depending on the brand of the tire.
 
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DirtHeadDavis

Active Member
What brand if tires. Most vibrations like that are either tires that aren’t balanced properly or a driveshaft issue. I’d start with the tires. It may take 2-3 times to get them balanced right depending on the brand of the tire.
Exactly. If one of your tires is not balanced chances are they all are not and moving them around isn't going to help. A shop may have only static balanced them since they are big 35" tires. Are you feeling it in your steering wheel, floorboard, etc?

Also as MericaMade said a 4" Lift is not healthy for stock shafts. Check your pinion angles.
 
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Sinister16

New member
The tires are Nitto ridge grapplers
The vibrations are more of an annoyance below 75 and above 80 it really starts shaking stuff you feel them in your feet, butt, and a little in the wheel but I'm thinking that is just transfer from everything else shaking.
Front pinion angle is 4.4 drive shaft is 6.7 and transfer case is 8.3
Rear pinion is 8.2 drive shaft is 8.3 and transfer case is 8.3 all measurements are taken on flat level ground with a Klien 935DAG angle finder
Let me know if I'm missing something please. sometimes I mis things haha
 

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Sinister16

New member
O and now for the butt chewing from you guys I did research this a bunch and I know there is a bunch of options both ways but after I first got it back from the shop balancing the tires I didn't trust them to do my tires again (they scratched up my last set of rims) I took off my wheel whaights and installed tire beads 16 Oz in each tire chart called for 12 - 14 Oz I first installed 12 then added another 4 after it still vibrated I have another 4 I can add to each but have not yet.
 
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CalSgt

Hooked
I don't know how much it maters with the rzepa joints on the factory shaft but the rear pinion angle looks wrong to me. Pinion snout should be parallel to the TC angle not pointing at the TC.
 

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DirtHeadDavis

Active Member
O and now for the butt chewing from you guys I did research this a bunch and I know there is a bunch of options both ways but after I first got it back from the shop balancing the tires I didn't trust them to do my tires again (they scratched up my last set of rims) I took off my wheel whaights and installed tire beads 16 Oz in each tire chart called for 12 - 14 Oz I first installed 12 then added another 4 after it still vibrated I have another 4 I can add to each but have not yet.
I'm sorry but I like girls.

Anyway that's why tire shops have expensive balancing machines. It's most likely driveline related since you have stock shafts and a big lift. Check out the chart above to get an idea and compare it to yours ^^^
 
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Snboarder113

Active Member
Based on the speeds you’re getting vibration I think you have death wobble that’s being masked by your steering dampener. Normally happens at 45ish and 65ish. I would Focus on your front end components. Alignment, tighten shit, etc etc.

Ditch the balance beads, I’ve ran them before, while they can get you by, they are not the same as an actually balanced tire and anyone that tells you differently is selling something. Also I hated listening to tire-maracas every time I left a stop light.
 
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Sinister16

New member
Ok guys last question for the afternoon until I can get home to turn some wrenches. So to adjust the pinion angle I need to unhook the upper tie rods. can I safely do that with it on the ground or will the axle try and rotate on me
 
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MericaMade

Active Member
Ok guys last question for the afternoon until I can get home to turn some wrenches. So to adjust the pinion angle I need to unhook the upper tie rods. can I safely do that with it on the ground or will the axle try and rotate on me
To be clear you are talking about upper control arms right? As long as you keep one arm connected you will be ok, but you are going to have some resistance and might need to manipulate the axle a little.
 
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Sinister16

New member
Awesome thanks for the help I had the jeep all blocked up when I installed the kit but I took the blocks back and you have to lift the hell out of it to get all the spring tension out now
 

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Sinister16

New member
Based on the speeds you’re getting vibration I think you have death wobble that’s being masked by your steering dampener. Normally happens at 45ish and 65ish. I would Focus on your front end components. Alignment, tighten shit, etc etc.
When I first read this I was like NO WAY every ball joint on my front end is brand new, and upgraded. No way in hell I have deth wabble. Then I thought that thought did cross my mind as well. Maaaaybeeee I better check it out. So I went back and checked the torque on every bolt in the front end and I did find a loose nut on the drag link. it didn't fix the problem but It did eliminate that question mark. I did drag my wife along and the vibration you differently fill it more in your seat than your feet or the wheel. I'll start messing with the pinion angle tonight.
 
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