Around 550 miles away from home on the way back from a funeral this last Saturday, we started to hear a low pitched whine (growl?) coming from the rear of the LX-450. It started almost unnoticeable until it was quite loud.
It's constant with the speed of the vehicle. From a few miles an hour to highways speeds it's noisy. Around 72mph it's somewhat quieter. Accelerating, decelerating or steady speed, the noise is there. Only changing pitch with the speed of the vehicle.
I headed to some streets with hills to do some testing.
With the transmission and transfer case in neutral, coasting down a hill, the sound is the same. Coasting down the hill with the drivers door open, the sound is definitely coming from behind.
We considered a one way rental car, but drove the LX-450 home anyway. The noise didn't seem to get worse.
At home, I put the car up on four jack stands and had the in the drivers seat with the speedometer up to 15mph while I probed the rear drive train for noise. I cobbled together this thing for the job:
The long end of the hose on my ear while I probed with the other end while the truck was running in drive on the jack stands at 15mph. It seemed noisiest near the rear diff flange, but the pitch seemed higher. The "growl" was very noticeable standing and facing either of the rear wheels. Whatever is causing the noise, the rear axle housing is doing a great job transmitting the sound out to the ends of the axle shafts.
While using the ih8mud search, it was mentioned that you could pull a diff plug and quickly put your thumb over the drain hole. Allowing inspection of the diff plug magnet with very little diff oil loss. Here is the magnet:
See the wire in front of the plug, that came from inside the diff and was stuck to the magnet. What part inside the axle housing has a wire? Note: This LX-450 does not have diff lockers.
In this video you can hear the sound at all speeds:
While I was under the truck today I checked the rear u-joints. I can move them very slightly. I made sure the rear u-joints were well greased. No change in sound after greasing up the rear u-joints.
No up/down play on the rear diff flange.
I'm thinking this is something in the rear diff.
Any ideas?
It's constant with the speed of the vehicle. From a few miles an hour to highways speeds it's noisy. Around 72mph it's somewhat quieter. Accelerating, decelerating or steady speed, the noise is there. Only changing pitch with the speed of the vehicle.
I headed to some streets with hills to do some testing.
With the transmission and transfer case in neutral, coasting down a hill, the sound is the same. Coasting down the hill with the drivers door open, the sound is definitely coming from behind.
We considered a one way rental car, but drove the LX-450 home anyway. The noise didn't seem to get worse.
At home, I put the car up on four jack stands and had the in the drivers seat with the speedometer up to 15mph while I probed the rear drive train for noise. I cobbled together this thing for the job:
The long end of the hose on my ear while I probed with the other end while the truck was running in drive on the jack stands at 15mph. It seemed noisiest near the rear diff flange, but the pitch seemed higher. The "growl" was very noticeable standing and facing either of the rear wheels. Whatever is causing the noise, the rear axle housing is doing a great job transmitting the sound out to the ends of the axle shafts.
While using the ih8mud search, it was mentioned that you could pull a diff plug and quickly put your thumb over the drain hole. Allowing inspection of the diff plug magnet with very little diff oil loss. Here is the magnet:
See the wire in front of the plug, that came from inside the diff and was stuck to the magnet. What part inside the axle housing has a wire? Note: This LX-450 does not have diff lockers.
In this video you can hear the sound at all speeds:
While I was under the truck today I checked the rear u-joints. I can move them very slightly. I made sure the rear u-joints were well greased. No change in sound after greasing up the rear u-joints.
No up/down play on the rear diff flange.
I'm thinking this is something in the rear diff.
Any ideas?