High pitch whine at 60 MPH after 5.38 re-gear

[Liv2Ryd]

So I'm 300 miles into breaking in my 5:38's. All the miles so far have been easy back road and very mild wheelin. Yesterday, I had to make a quick run so I jumped on the highway, when I got up to 58mph (verified by my phone speedo app), I started to hear a high pitch whine coming from the front of the Jeep. As I continued going faster, the whine got louder so I back it off till it stopped. I cruised for another few miles and slowly picked up speed again and sure enough, at 58-60mph, the whine started back up again. The noise gradually gets louder as MPH increases. When I back it down under 58, all is well. No vibes are associated with the noise, just a sound. My TJR is an 06 4.0L with 42LRE tranny with 35K miles. Its got a 4" RE lift and 35's. Thoughts?

 

[Mr. Bills]

Drive at less than 58 mph directly to your gear installer and have him diagnose.

 

[Chris]

It’s not a cyclical vibration at all, right?

https://wranglertjforum.com/threads...ler-tj-vibrations-after-re-gear-thread.32445/
If not, go back to the shop you re-geared it and see what they say. They should warranty their work.

 

[Lou]

Yeah who did the gears? noises are notoriously difficult to troubleshoot over a forum without good videos/ sound recordings.

 

[Liv2Ryd]

It’s not a cyclical vibration at all, right?

https://wranglertjforum.com/threads...ler-tj-vibrations-after-re-gear-thread.32445/
If not, go back to the shop you re-geared it and see what they say. They should warranty their work.

Its not cyclical. Its going back to the shop on Monday for my 500 mile inspection and diff lube exchange. I called today and the service mgr is going to get back to me.

 

[Chris]

Its not cyclical. Its going back to the shop on Monday for my 500 mile inspection and diff lube exchange. I called today and the service mgr is going to get back to me.

Sounds like there’s definitely a problem with the install in that case.

 

[Liv2Ryd]

Sounds like there’s definitely a problem with the install in that case.

I was afraid that might be the case. These guys have done tons of regears so I'm sure they can get to the bottom of it. It might be their 1st 5:38 exchange.

 

[Liv2Ryd]

Brought the TJR back in yesterday for its 500 mile regear service. I have avoided highways since I discovered the dreaded whine. I decided to take the highway since its a much longer haul via backroads to the shop. Got a little curious while cruising at 55 and pushed the speed up to 60. No whine. Pushed it up to 65. Still no whine. Pushed it up to 70 and the whine started (sounds like a tea kettle whistling). What was weird is it would ebb and flow between 65-70mph. I backed it down to 60 and finished the trip whine free.

When I arrived, the shop owner and I took it for a test ride and he observed the same noise and stated he would do a test with some type of microphone later that am. When I picked up the TJ later in the day, he said they found no issues with the gears but it appears the sound is coming from my lightbar! I'll be removing the bar to see if this is truly the case but i'm hopeful my regear is not the issue. On the ride home I ran the TJ up to 70-75 and observed no drivetrain vibes so it looks like I may have dodged the dreaded "vibrations after regear" issues some have had.

BTW, the Black Magic brake/rotors have bedded in now and all I can say is wow, what a difference vs the stock crap. My Jeep now stops with authority. Along with the 5:38 regear and Savvy steering, my TJR is now super fun to drive on road. It ain't no sportscar but it goes where I point it, stops on a dime and has no shake/shimmy action any longer.

 

[MountaineerTom]

Did you have the light bar on before the regear? Did it make noise then?

I’ve heard they can cause a whistling noise but it seems odd if it started after the regear.

 

[Liv2Ryd]

Did you have the light bar on before the regear? Did it make noise then?

I’ve heard they can cause a whistling noise but it seems odd if it started after the regear.

Good question. I honestly can't answer because i purchased the TJR in April and have very few highway miles on it. It did come with the lightbar and I can't say I ever noticed any whine before the regear but i never checked my speed either. To be honest, as purchased, the TJR kinda sucked on the highway between being way under geared, crappy brakes and wandering steering. Highway speeds were kinda scary.

 

[AndyG]

Did you have the light bar on before the regear? Did it make noise then?

I’ve heard they can cause a whistling noise but it seems odd if it started after the regear.

Likely couldn't get up to speed with wrong gears

I've heard of that , but boy I'd keep my ears on the gears after you remove it.

 

[Liv2Ryd]

Likely couldn't get up to speed with wrong gears

I've heard of that , but boy I'd keep my ears on the gears after you remove it.

The shop has already confirmed that if the gears are ultimately the issue, they will do a warranty replacement.

 

[AndyG]

The shop has already confirmed that if the gears are ultimately the issue, they will do a warranty replacement.

It's good to have those conversations early. You will enjoy the regear. It makes everything better.

 

[MountaineerTom]

Sounds like your plan to pull the light bar and check for the noise will give you the answer. I hope it’s just your light at. Good luck.

I‘ve seen a post somewhere where someone put some door edge guard on the cooling fins of a light bar to eliminate wind noise (or maybe just lessen it). I don’t have a light bar or any experience with them, so I could be wrong in what they used to quiet it down. For some reason I’m thinking door edge guard.

 

[Liv2Ryd]

It's good to have those conversations early. You will enjoy the regear. It makes everything better.

I agree. I'm taking the Jeep out for joy rides now cause its so fun to drive. I stick mostly to country roads and here in New England we have plenty of those. With the OD off, the motor now runs in the meat of its RPM range which keeps the Jeep and me smiling.

 

[LONGJP2]

Not a fan of light bars.
However, if it's making noise and you want to keep it, this might help.

https://aeroxindustries.com/?gclid=EAIaIQobChMIp6m7worh6gIVDb7ACh2VVwjSEAAYASAAEgJpHPD_BwE

 

[Mr. Bills]

Light bar "whine" is a well known phenomenon. Google should provide you with a panoply of hacks and workarounds.

However, the best solution is to sell the light bar. You didn't really want a "bro" jeep anyway.

 

[Jerry Bransford]

Sounds like a bad gear set up perhaps made worse if they filled the diffs with a synthetic gear lube. It's especially important to run a conventional gear lube during the critical breakin to help the gears run as cool as possible.

 

[Mr. Bills]

The gears have already been inspected after break-in. The inspection revealed no issues with the gears or the set up or the gear oil used. [post #8]

The whine has been traced to the lightbar, a common problem frequently discussed on other brand offroading forums that OP had not yet experienced during his limited time driving on the highway in his new-to-him jeep.

Sounds like a successful vibration-free re-gear to 5.38 to me and good news for OP.

 

[steelhd]

Be sure you have isolated the source of the sound. After my last expensive major modification there was a bothersome intermittent high pitched whine that really confused me. One day the sound followed me into the house and I realised it had been coming from the passenger seat.