Whining noise from transfer case

[slowfox]

Hello gents,

I have some strange whining noise coming from the transfer case area. Usually noticeable already at 30mph and changes its pitch while accelerating and decelerating becoming most prominent at 55-75mph. I ruled out transmission by putting in neutral. I also tried in 4H without any change. I have a 2018 JLUR 3.6 6MT.

Any ideas how to approach on troubleshooting this?

Best,
The Slow Fox

 

[OverlanderJK]

Pinion bearing.

 

[slowfox]

Transfer case was replaced by Jeep after they claimed to have pinpointed the noise to have been indeed coming from it.

After T-case replacement I am still getting the same noise, the only difference now is that I only get the noise when accelerating - noise is not showing up when decelerating or while cruising with inertia in neutral. @OverlandJK any thoughts?

 

[OverlanderJK]

Transfer case was replaced by Jeep after they claimed to have pinpointed the noise to have been indeed coming from it.

After T-case replacement I am still getting the same noise, the only difference now is that I only get the noise when accelerating - noise is not showing up when decelerating or while cruising with inertia in neutral. @OverlandJK any thoughts?

Remove the rear drive shaft and drive in 4 high and see if it goes away.

 

[slowfox]

Remove the rear drive shaft and drive in 4 high and see if it goes away.

What exactly would that tell me? The noise doesn't come from the rear it comes from just under the stick shift.

 

[WJCO]

What exactly would that tell me? The noise doesn't come from the rear it comes from just under the stick shift.

Do what he says. Noises can easily transfer as vibrations and appear in different locations than they originate from.

 

[slowfox]

Do what he says. Noises can easily transfer as vibrations and appear in different locations than they originate from.

I understand that vibrations can transfer as noises. Usually when I do something I need to understand what exactly is that I am doing and what information I will gain from the particular troubleshooting step. This being said "do what he says" doesn't help me much in understanding what I will learn from that information and what will be ruled out as possible cause.

 

[OverlanderJK]

I understand that vibrations can transfer as noises. Usually when I do something I need to understand what exactly is that I am doing and what information I will gain from the particular troubleshooting step. This being said "do what he says" doesn't help me much in understanding what I will learn from that information and what will be ruled out as possible cause.

If you pull the rear shaft you will rule out the pinion bearing in the rear end which is likely your problem. You are welcome to do whatever you would like though.

 

[WJCO]

I understand that vibrations can transfer as noises. Usually when I do something I need to understand what exactly is that I am doing and what information I will gain from the particular troubleshooting step. This being said "do what he says" doesn't help me much in understanding what I will learn from that information and what will be ruled out as possible cause.

Any powertrain noise/vibration typically occurs during acceleration or deceleration. If you remove the rear driveshaft and drive it in 4hi, you have just isolated the issue to the rear driveshaft or rear differential.

Make sure and mark the rear driveshaft and rear pinion yoke with nail polish so that you can reinstall it in the same position.

 

[slowfox]

If you pull the rear shaft you will rule out the pinion bearing in the rear end which is likely your problem. You are welcome to do whatever you would like though.

Well the reason I am asking here is because I am sure people here have much more experience than I have. I am not trying to say that doesn't make sense but I am rather trying to understand the process.

It is worth noting that the noise was in place before my entire rear axle was swapped due to the failed sensor causing locker issues. The noise persisted after the axle swap. To my understanding this would already rule out pinion bearing issues in the rear as essentially it was replaced with a new assembly, correct?

 

[OverlanderJK]

Well the reason I am asking here is because I am sure people here have much more experience than I have. I am not trying to say that doesn't make sense but I am rather trying to understand the process.

It is worth noting that the noise was in place before my entire rear axle was swapped due to the failed sensor causing locker issues. The noise persisted after the axle swap. To my understanding this would already rule out pinion bearing issues in the rear as essentially it was replaced with a new assembly, correct?

One would assume but that is information we did not have. You could still do it to rule out the driveshaft. Is it factory or aftermarket?

 

[slowfox]

One would assume but that is information we did not have. You could still do it to rule out the driveshaft. Is it factory or aftermarket?

Factory driveshaft.

 

[WJCO]

Well the reason I am asking here is because I am sure people here have much more experience than I have. I am not trying to say that doesn't make sense but I am rather trying to understand the process.

It is worth noting that the noise was in place before my entire rear axle was swapped due to the failed sensor causing locker issues. The noise persisted after the axle swap. To my understanding this would already rule out pinion bearing issues in the rear as essentially it was replaced with a new assembly, correct?

Had no idea the axle was swapped. I almost wonder if it's something inside the transmission.

 

[slowfox]

Had no idea the axle was swapped. I almost wonder if it's something inside the transmission.

I was wondering the same. Initially with the original T-case noise was there even while cruising in neutral which made me believe it wasn't the transmission, but now noise is only present when accelerating e.g. when there is torque through the drivetrain. After the t-case swap releasing the gas or cruising in neutral eliminates the noise. This in general logic points me back to the transmission.