Vibration at highway speeds still

[CherylPertuch]

Hello everyone! I'm at a dead end with my TJ. First off, I'll list my set up:
2003 Rubicon Tomb Raider
6" Rough Country Long Arm Lift
Rough Country HD Steering Upgrade
33" Faulken ATW3 Tires

So after doing a 1" Transfer Case drop replacing both driveshafts (SYE)/U joints, new axle bearings, ball joints, control arm bushings, sway bars and links, drag link, stabilizer, AND swapping out the old rear (someone put a circle k pinion, a dana ring gear and yukon locker with a shim on the sun gear. Was also two dif ratios. Yes I know, it shouldn't have went down the road. It did...poorly.) Now putting the correct rear and housing did eliminate some of the vibration. It used to come on about 35 mph, now it's not til 55-60. My spedo is reading true as well, previously if the speedometer read 35 you were actually going 25. Tires are balanced, operating angles are maxed in spec. Any ideas would be greatly appreciated cause I'm outta ideas and running out of cash lol
Thanks!

 

[Flivver250]

Two pieces of advice I offer from personal experience...Never trust your tire balancing. Larger tires and a Wrangler are a very sensitive combo. In my quest for a vibration-free ride the tire balance was the #1 factor and #2 was the pinion angle. I can now run mine smoothly at high speed, no issues. I would hope the SYE would eliminate the need for the TC drop.

 

[Goatman]

I would first look to tire/rim balance for a vibe that hits at a specific speed consistently. Is the vibe coming from the front or the back? Do you feel it in the steering wheel or the seat? What type of rims do you have? Does the vibe get better if you pull the front driveshaft?

 

[Chris]

Have the vibrations always been here, or did they happen after you did some work to it?

I'm trying to understand more, as the first post was a bit confusing (sorry, just woke up).

 

[freedom_in_4low]

you can tell the difference between a tire and a driveline vibration pretty easily, because a tire vibration is about the speed of the tire rolling, and the driveline vibration is about 4x that. It's more of an inaudible buzz, making your mirrors blurry kind of vibration.

If it still sounds like a driveline vibration, pull one driveshaft at a time and drive it on one and see in which case the vibration disappears.

 

[Alex01]

Hello everyone! I'm at a dead end with my TJ. First off, I'll list my set up:
2003 Rubicon Tomb Raider
6" Rough Country Long Arm Lift
Rough Country HD Steering Upgrade
33" Faulken ATW3 Tires

So after doing a 1" Transfer Case drop replacing both driveshafts (SYE)/U joints, new axle bearings, ball joints, control arm bushings, sway bars and links, drag link, stabilizer, AND swapping out the old rear (someone put a circle k pinion, a dana ring gear and yukon locker with a shim on the sun gear. Was also two dif ratios. Yes I know, it shouldn't have went down the road. It did...poorly.) Now putting the correct rear and housing did eliminate some of the vibration. It used to come on about 35 mph, now it's not til 55-60. My spedo is reading true as well, previously if the speedometer read 35 you were actually going 25. Tires are balanced, operating angles are maxed in spec. Any ideas would be greatly appreciated cause I'm outta ideas and running out of cash lol
Thanks!

Can you post a photo of the drive shafts so we can eyeball the angle / if anything looks out of place? It would be even better if you could take measurements of the pinion angle and DS angle F/R. For the pinion angle use the flat surface next to the differential cover.

Assuming the tires are balanced I would pull the front or rear driveshaft to see if the vibration goes away.

 

[TurboTJ]

Have you installed a DC rear drive shaft? A 6 inch lift, even with the 1 inch transfer case drop, is too much without a DC shaft. You mention SYE/U joints. The TJR does not need an SYE. Maybe when saying SYE you meant DC?

 

[Vinman]

Rotate the tires and see if the vibration changes any, if not, that will rule out tire balance.