Floor vibration?

[mortuar]

Remove all eight bolts (circled in red).
Use a flat head screwdriver to pry the driveshaft apart from the yoke.
With the rears wheels off the ground, rotate the yoke until yellow dot (1) and yellow dot (2) are 180 degrees from each other. The two yellow dots should be lined up from the factory.
Bolt everything back up and take it for a spin.
If that fixed your problem you'll want to take the bolts back out and apply some blue locktite.

Thank you for all the detail! Does this mean they are being balanced incorrectly from the factory? I wonder if there are issues we can cause by rotating this.

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[Mr G]

Thank you for all the detail! Does this mean they are being balanced incorrectly from the factory? I wonder if there are issues we can cause by rotating this.

No, these are two separate things made probably by different vendors, they balance their product but when the two are connected wrong at the factory we get vibration. You would think there’s a spec on how the assembly should be mated. They skipped that on mine evidently, hahahaa. I’ve seen blue dots and yellow, not sure what that means. But mine is fixed so I don’t care

 

[jeepfan30]

Aftermarket driveshafts have dots and arrows too to ensure they are put together “in phase” and remain balanced. Leaving a driveshaft unbalanced will cause premature wear on transfer case and pinion bearings. You won’t hurt anything by rotating it.

 

[Aramis76]

What would be the torque value for those 8 bolts ?

Going to have to give this a try on mine, 2020 2 door Rubicon, delivered yesterday, vibration between 60-65mph.

 

[jeepfan30]

Just want to provide an update since I see the Gladiators are having the same harmonic noise issue at very specific speeds. https://www.jeepgladiatorforum.com/...ut-of-the-dealership-parking-lot.21161/page-5

Rotating the driveshaft holes did not solve the problem. I have since completely removed the rear DS and the harmonic noise still persists. Others have had their entire rear axle and rear driveshaft replaced with no fix. https://www.jlwranglerforums.com/fo...noise-at-highway-speeds-63-67ish.10189/page-6

Waiting for "frizille" to have his transfer case replaced in the coming weeks to see if that helps. Other members on the Gladiator thread are getting front axle shafts replaced as part of the diagnostic process. FCA is saying its normal due the way the front axle is designed (FAD).

 

[redsyphon]

Following to see if anyone has been able to locate a solid answer on the torque values of the rear flange bolts. I've done some googling, but wasn't able to find a solid answer... found ranges from 70 to 44 ft lbs.

 

[rayzjeep]

Are you talking about the T50 bolts that attach the driveshaft flange at the axle, I found 30 ft lbs in my googling. Rotating the driveshaft didn't seem to help any though....didn't seem to may any difference at all which leads me to believe it's something else possibly.

 

[redsyphon]

I went through all of the different rotation points without any change. A wheel balance has helped, but there is still a harmonic/patterned pulsing vibration at 62-63 mph.

She drives fine otherwise and the vibration occures regardless of neutral vs. skinny pedal.

At this point, I'm just going to driver her and enjoy her. It may just be an odd vibration and im being over paranoid after going from a manual to auto JLU...

Still going to keep following in the hopes someone else finds answers.

 

[Qjoh5510]

Took a peek at my driveshafts today. The rear definitely looks like it’s one bolt off on the markings. Going to rotate it this weekend and see if that changes the vibrations I’m having.

 

[rayzjeep]

Did you notice any difference after rotating the driveshaft? I rotated mine 180degrees a couple weeks ago and didn't feel any difference. So I'm going to rebalance the tires for a third time and see if that helps sometime this week.

 

[Qjoh5510]

Did you notice any difference after rotating the driveshaft? I rotated mine 180degrees a couple weeks ago and didn't feel any difference. So I'm going to rebalance the tires for a third time and see if that helps sometime this week.

I actually haven’t driven it since I rotated it to line up the marks. I’ll find out within the next few days on my next driving opportunity. I have a beater Honda I use to go to work so the jeep sits in the garage until the weekends.

 

[Qjoh5510]

So I drove the jeep to work today. And then to the car wash afterwards. There is no more rhythmic vibration at 63mph after aligning the yellow dots on the transfer case side of the rear driveshaft. BUUUT... I’m still battling what I believe to be a tire vibration in the mid 50s. Unless the vibration has moved lower in the speed range due to installing bigger tires. Too many variables to say anything absolute right now (37s and possibly being unbalanced) unless I find someone with factory tires I can swap on for a quick ride. Going to try and get the tires rebalanced this weekend to rule that out. If all vibes are gone after a tire balance then bingo. I’m good to go. But if not then I believe the vibes have just lowered in speed due to bigger tires. Which would then lead me to believe it’s possibly the internals in one of the axles. If that is the case I guess my next step would be a regear, since I want to do that anyway, and see what changes.

 

[rayzjeep]

I tried rebalancing the tires at Discount 3 times and tried the driveshaft rotation thing and didn't notice any difference. I did notice this morning when driving uphill into a strong head wind that the vibration seems worse so maybe its an exhaust or motor mount issue because of more load turning the 37's.

 

[Qjoh5510]

I tried rebalancing the tires at Discount 3 times and tried the driveshaft rotation thing and didn't notice any difference. I did notice this morning when driving uphill into a strong head wind that the vibration seems worse so maybe its an exhaust or motor mount issue because of more load turning the 37's.

With 37s are your vibrations still in the 63-64 mph range? Just curious.

 

[rayzjeep]

With 37s are your vibrations still in the 63-64 mph range? Just curious.

Yep...right in that range is when they start and are most noticable. Still have it some at higher speeds though but it doesn't really increase in severity.

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