Thrumming Noise at Highway Speeds (63-67ish)

JeepJohn

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Can you tell a difference in the driving?
I had the steering box TSB performed and the steering is much better especially at highway speeds. The thrumming at about 63+- mph is still present. Has anyone who had the drive shaft replaced been able to get the thrumming to go away??
 

Gcodejedi

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Same issue here. 2020 JLUR. Thrummed from day one off the lot. I took it to the dealer and they acknowledged the vibration during a ride along. A few hours later they called and said they drove a like equipped rubicon on their lot and it does it as well, so it’s “normal”.

The thrumming for me initially started in the low 50mph range and went away in the low 70mph range. 85 is perfectly smooth.

Since then, I’ve put about 7500 miles on the Jeep and have tried several things to try and isolate the problem.

1. I checked the wheel balance myself using a buddies wheel balancer. All were fine. As a part of doing this, I noticed the wheel lock lugs were hella tight. Way tighter then the other lugs. Each wheel was reinstalled in the location they came from and lugs torqued to 120. No change.

2. I rotated tires. No change.

3. I retorqued all wheels to 100lbft. Thrumming in the 50mph range cleared up. Now only thrums from low 60s to low 70s.

4. Feeling a bit encouraged, I retorqued wheels to 80lbft. No change.

5. I put rear axle of Jeep on Jack stands and ran up to 70mph. The thrum was present but instead of oscillating it was constant hum. Btw, if you try this, you have to turn off traction control and the Jeep will throw service abs/traction control lights. They go away after driving on the road a few miles. Just a data point, no changes.

5. I removed rear drive shaft and drove the Jeep in 4hi. I drove all through the affected speed range, probably annoyed a few people on the highway in the process. Thrumming completely gone.

6.Feeling confident I had a driveshaft issue, I used a dial indicator and measured runout on the pinion shaft, transfer case output shaft and both ends of the drive shaft. The pinion and transfer case output shaftshafts (on the yoke) about .001 radial and axial runout. The driveshaft at the pinion end had 14 thou runout. at this point I was convinced I had a driveshaft issue.

7. I tried rotating the driveshaft 180 degrees at the pinion yoke as has worked for some.This didn’t work for me. Over a few weeks I rotated the drive shaft one bolt hole at a time. Thummed at all clocked positions.

8. I ordered a new driveshaft from Adam’s. Installed with new yokes at transfer case and pinion. Wahwahwah. Still thrums. Below 60 is smooth and 75+ is smooth. Driveshaft looks great tho:)

In all of this, I have noticed that the pinion has more rotational play than maybe it should. Gear lash should be in the 5 thou range, and I can feel this when turning the pinion yoke, but there is also “extra” play beyond the gear lash... so

9. I pulled the rear axle cover off to see what’s happening. The jeep was parked on the ground with the parking brake on. I would think that the ring gear/diff carrier would be locked and wouldn’t move. However, as I turn the pinion back and forth, the ring gear/carrier also turn back and forth about half a tooth worth. The only way this could be is if there is slop in the spider gears. Unfortunately I could not get a good look at the spiders because of how closed in the locking diff case is. Would sloppy spider gears cause thrumming? Idk. Can’t be good tho.

I put the factory DS back on. I’m debating playing the warranty game or just building the Jeep with the hope I fix the problem eventually in the process.
 

Gcodejedi

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Problem fixed! Driveshaft replaced, that didn’t do it. Rear differential replaced, problem solved! Shout out to Bedford Hills Chrysler Jeep!
Did they replace the ring, pinion, and bearings as well?
 

brewtus98

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Mine had the noise prior to getting the axle completely rebuild due to worn-out clutches in the LSD. Does it just the same after the axle rebuild. My GMC pickup also had the same sort of issue. I chalk it up to vehicle harmonics.
 

BubbaJeep

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I have a 2020 Rubicon with 1500 miles on it. It also has the Thumming sound at 60 and up. Went to the dealer and they wouldn't even look at. I got thats how it is get used to it. My jeep also wanders a lot. Kinda sad. Not my first Jeep but maybe my last!!!!
 

JeepJohn

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I have a 2020 Rubicon with 1500 miles on it. It also has the Thumming sound at 60 and up. Went to the dealer and they wouldn't even look at. I got thats how it is get used to it. My jeep also wanders a lot. Kinda sad. Not my first Jeep but maybe my last!!!!
Hang in there. Get the steering TSB done regarding the wandering. As far as the thrumming, take it to another dealer.
 

BubbaJeep

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Hang in there. Get the steering TSB done regarding the wandering. As far as the thrumming, take it to another dealer.
I am considering my options at this point. Not willing to spend time and effort to only be told by the dealer ( its a jeep thing) or (thats normal). Its not normal for any 2020 vehicle to make a sound so loud you can hear it over the radio. Dealers can't fix it and in my case the service manager actually acted like he didn't hear it. If you don't acknowledge the noise then you don't have to fix it. I took the sales manager for a 5 minute drive and he's the one that set the appointment to bring it in. It will just be a run around for sure. Jeep needs to step up fix this issue before we are all driving Broncos. I would say Jeep doesn't Care!!!!!!
 

BubbaJeep

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About what frequency and does it "cycle" intensity?

It is possible for a vehicle to have a cyclic drumming or vibration sound at the frequency of ECM "feedback" control. This occurs as torque changes slightly due to Air Fuel Ratio management by the engine computer. This would be noticeably cycling, about every second or so. I have seen cross-mounted muffler systems transmit the sound into a rear floor panel on various types of vehicles. Remember, the sound waves off the side of the muffler are moving air at a frequency, and a larger surface is able to absorb more of that energy.

That is not the only source of such a noise. I have seen radiator hoses that were hardened, or installed with a twist, or pulled too tight (short) that can transmit the changes of engine torque into the body. Remember....closed-loop feedback engine control changes the amount of torque due to the small air-fuel ratio change.

A thrumming noise that cycles intensity over a longer period of time can be caused by tire RFV that is responding to an opposite tire which is turning at a slightly different frequency. These conditions will usually run in 7-14 second periods of "more/less" noticeable intensity. This is a common condition on straight axles and peak vibration (not very high amplitude) typically occurs when the "peak" RFV spot on a tire is at 90 degrees, than 180 degrees, than 270 degrees to the peak point of the opposite side tire. You would be surprised how matching tires do not run at the same rotation speed. I have worked on "worst case" vehicles where we had to get specially selected tires to minimize the change period (we could stretch it out to over a minute or more, which is much less bothersome for the driver).

Sometimes tires can be tested on a wheel balancer with RFV measurement, and the condition can be improved by moving the tire on the rim (which can reduce the peak RFV in some cases). RFV measurements are in numbers and "13 is unlucky" meaning 13 or more is likely to be an unsatisfactory tire for straight axle applications.

Certain roads can exacerbate this condition, where there is small "pattern rippling" in the road surface. I was having some issues with my Rubicon on a few roads in our area. I did pretty much eliminate it by getting the tire pressures down to normal (hard to believe the dealer handed over the Jeep with 45 PSI in all four tires).

There is a lot more going on with "tire stuff" as you can see, and it gets more difficult when the tires are aggressive tread pattern. Try a test drive with about 30 psi in the tires...just to see if it is better or worse, and pay attention to the frequency within the thrum sounds.

Hope this helps, at least to understand some...….Jim
After reading several post I and others have had the dealer bolt on 4 different tires and we have the exact same thrumming sound with different tires. I can feel it in my steering wheel as soon as it starts right around 60mph. So its not a tire issue.
 

JeepJohn

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After reading several post I and others have had the dealer bolt on 4 different tires and we have the exact same thrumming sound with different tires. I can feel it in my steering wheel as soon as it starts right around 60mph. So its not a tire issue.
I agree that it doesn’t seem like it’d be a tire issue. However, I had mine to my dealer for an oil change yesterday and asked them to check this. I had the same thrumming/vibration at 60 to 70ish mph.. Of course they balanced the tires and said they couldn’t “replicate” the issue after they did this. I told them it wasn’t the tires and that I’d be back another day for them to figure it out... Then when I drove it, it seemed better. Maybe the tires have something to do with it?
 

Redneck_Jedi

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I agree that it doesn’t seem like it’d be a tire issue. However, I had mine to my dealer for an oil change yesterday and asked them to check this. I had the same thrumming/vibration at 60 to 70ish mph.. Of course they balanced the tires and said they couldn’t “replicate” the issue after they did this. I told them it wasn’t the tires and that I’d be back another day for them to figure it out... Then when I drove it, it seemed better. Maybe the tires have something to do with it?
Maybe slightly. I know after I switched out my Sport Wheels/Tires with the Rubicon set, the 'Thrumming" was still there.
 

imbuere

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Same issue here. 2020 JLUR. Thrummed from day one off the lot. I took it to the dealer and they acknowledged the vibration during a ride along. A few hours later they called and said they drove a like equipped rubicon on their lot and it does it as well, so it’s “normal”.
This. This is why I freaking hate Jeep service. No other car manufacturer would get away with this shit.

For what it's worth, my bet is this is a drive train issue. I had the same thing happen on my old XJ.
 

JeepCares

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Same issue here. 2020 JLUR. Thrummed from day one off the lot. I took it to the dealer and they acknowledged the vibration during a ride along. A few hours later they called and said they drove a like equipped rubicon on their lot and it does it as well, so it’s “normal”.

The thrumming for me initially started in the low 50mph range and went away in the low 70mph range. 85 is perfectly smooth.

Since then, I’ve put about 7500 miles on the Jeep and have tried several things to try and isolate the problem.

1. I checked the wheel balance myself using a buddies wheel balancer. All were fine. As a part of doing this, I noticed the wheel lock lugs were hella tight. Way tighter then the other lugs. Each wheel was reinstalled in the location they came from and lugs torqued to 120. No change.

2. I rotated tires. No change.

3. I retorqued all wheels to 100lbft. Thrumming in the 50mph range cleared up. Now only thrums from low 60s to low 70s.

4. Feeling a bit encouraged, I retorqued wheels to 80lbft. No change.

5. I put rear axle of Jeep on Jack stands and ran up to 70mph. The thrum was present but instead of oscillating it was constant hum. Btw, if you try this, you have to turn off traction control and the Jeep will throw service abs/traction control lights. They go away after driving on the road a few miles. Just a data point, no changes.

5. I removed rear drive shaft and drove the Jeep in 4hi. I drove all through the affected speed range, probably annoyed a few people on the highway in the process. Thrumming completely gone.

6.Feeling confident I had a driveshaft issue, I used a dial indicator and measured runout on the pinion shaft, transfer case output shaft and both ends of the drive shaft. The pinion and transfer case output shaftshafts (on the yoke) about .001 radial and axial runout. The driveshaft at the pinion end had 14 thou runout. at this point I was convinced I had a driveshaft issue.

7. I tried rotating the driveshaft 180 degrees at the pinion yoke as has worked for some.This didn’t work for me. Over a few weeks I rotated the drive shaft one bolt hole at a time. Thummed at all clocked positions.

8. I ordered a new driveshaft from Adam’s. Installed with new yokes at transfer case and pinion. Wahwahwah. Still thrums. Below 60 is smooth and 75+ is smooth. Driveshaft looks great tho:)

In all of this, I have noticed that the pinion has more rotational play than maybe it should. Gear lash should be in the 5 thou range, and I can feel this when turning the pinion yoke, but there is also “extra” play beyond the gear lash... so

9. I pulled the rear axle cover off to see what’s happening. The jeep was parked on the ground with the parking brake on. I would think that the ring gear/diff carrier would be locked and wouldn’t move. However, as I turn the pinion back and forth, the ring gear/carrier also turn back and forth about half a tooth worth. The only way this could be is if there is slop in the spider gears. Unfortunately I could not get a good look at the spiders because of how closed in the locking diff case is. Would sloppy spider gears cause thrumming? Idk. Can’t be good tho.

I put the factory DS back on. I’m debating playing the warranty game or just building the Jeep with the hope I fix the problem eventually in the process.
I have a 2020 Rubicon with 1500 miles on it. It also has the Thumming sound at 60 and up. Went to the dealer and they wouldn't even look at. I got thats how it is get used to it. My jeep also wanders a lot. Kinda sad. Not my first Jeep but maybe my last!!!!
Maybe slightly. I know after I switched out my Sport Wheels/Tires with the Rubicon set, the 'Thrumming" was still there.
Hello everyone,
We are sorry to hear that your dealer has been unable to resolve this concern for you in the past. Our team would like to offer our additional services alongside your future dealer appointments. Please send us a private message with your VIN so that we may connect you with a specialist for further support.

Kathryn
JeepCares
 

BubbaJeep

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Hello everyone,
We are sorry to hear that your dealer has been unable to resolve this concern for you in the past. Our team would like to offer our additional services alongside your future dealer appointments. Please send us a private message with your VIN so that we may connect you with a specialist for further support.

Kathryn
JeepCares
I will be happy to PM you with my VIN #. However and please I mean no disrespect but as you can see this is an ongoing issue and the same result with every trip to the dealer. I was told there is nothing wrong its normal as many others? How can a noise/vibration that I feel in my steering wheel and hear over the radio be normal on a 2020 Jeep with less than 500 miles on it? This is my first JL not my first Jeep and so far for a 55000 dollar Jeep I am less than impressed. I will accept any help I can get at this point!!!
 

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