Physicistkev
Member
2018 JLU Sport S. Rancho 3” lift with stock wheels and 35” tires along with 4.56 gearing. Adams front drive shaft and stock rear drive shaft. All installed at 20k miles and now has 50k miles. Isn't abused, but does go on blue trails a few times a year and I’ll venture over a black obstacle on occasion. Tows a small boat, around 3000#s, to and from the ramp (30 miles one way) and I did tow it from Northern Virginia to the Florida Keys and back in June.
The issue started about a week ago. Only after being warmed up. Happens quicker when towing or when driven harder.
Sounds like a chirp, or a kazoo (yeah it’s strange), that is not constant. My daughter says it sounds like a cricket. I’ve never heard a car make a noise like this. Think of a chirping fan belt, but more organic. Anywho…
It chirps in time with the rotation of the rear drive shaft and is coming from the rear half of the car. It happens at low speeds (15mph to 30mph) and it chirps under light acceleration. It chirps in 2wd, 4wd and 4w low. The speed is much slower in 4w low. Oh yeah, happens in reverse at the same speed. Pressing on the gas more, makes it go away. Turning and putting the car in neutral makes no difference. Braking or using the parking brake makes no difference. If I let off the gas, it continues to chirp until I reach a speed of about 15mph or less. However, when I take my foot of the accelerator, sometimes it’s intermittent as I slow down.
I’m thinking CV joints on the rear drive shaft or the rear differential. The differential seems unlikely as the chirp sounds “open”. Like it’s not inside something or muffled in any way. I would swear someone taped a harmonica with a way to make it oscillate under my car.
The differential doesn’t make any grinding, whirring, humming or any of the classic bearing failure sounds. I haven’t checked the fluid yet, but that will happen tomorrow. Searching for the forbidden glitter.
CV boots look perfect on the drive shaft. No leaks or fluid can be seen on the rear differential or drive shaft.
GoPros will get mounted after the rear differential fluid check and hopefully I can locate the sound with more fidelity.
Anyone have any suggestions I might be missing? Thanks in advance.
The issue started about a week ago. Only after being warmed up. Happens quicker when towing or when driven harder.
Sounds like a chirp, or a kazoo (yeah it’s strange), that is not constant. My daughter says it sounds like a cricket. I’ve never heard a car make a noise like this. Think of a chirping fan belt, but more organic. Anywho…
It chirps in time with the rotation of the rear drive shaft and is coming from the rear half of the car. It happens at low speeds (15mph to 30mph) and it chirps under light acceleration. It chirps in 2wd, 4wd and 4w low. The speed is much slower in 4w low. Oh yeah, happens in reverse at the same speed. Pressing on the gas more, makes it go away. Turning and putting the car in neutral makes no difference. Braking or using the parking brake makes no difference. If I let off the gas, it continues to chirp until I reach a speed of about 15mph or less. However, when I take my foot of the accelerator, sometimes it’s intermittent as I slow down.
I’m thinking CV joints on the rear drive shaft or the rear differential. The differential seems unlikely as the chirp sounds “open”. Like it’s not inside something or muffled in any way. I would swear someone taped a harmonica with a way to make it oscillate under my car.
The differential doesn’t make any grinding, whirring, humming or any of the classic bearing failure sounds. I haven’t checked the fluid yet, but that will happen tomorrow. Searching for the forbidden glitter.
CV boots look perfect on the drive shaft. No leaks or fluid can be seen on the rear differential or drive shaft.
GoPros will get mounted after the rear differential fluid check and hopefully I can locate the sound with more fidelity.
Anyone have any suggestions I might be missing? Thanks in advance.
