I think I have what is front end axle noise. It is a higher pitched noise that goes back and forth between two frequencies about twice a second. It doesn't sound like tire noise that I am used to with the BFG tires. So far I have spent some time running on a jack stands and swapping some parts with spares to try and change the noise. The noise starts around 20MPH and seems worse on acceleration or coasting. At 40MPH its very clear. Engine speed or transmission gear does not vary the noise. Applying the brakes or deceleration don't really change it either. There is absolutely no vibration - it is only a noise
- Tried removing front driveshaft - no difference
- Tried swapping each wheel bearing with a spare, and each tire with a spare - no difference
- Inspected front and rear brakes; found rear left adjuster may have been grooving the brake drum. No change after repair
- Ran on jack stands up to 40MPH in 2wd, 4wd, with front and rear driveshafts alternately removed and both removed - don't really hear it! What I do hear is a god awful noise from the transmission when it shifts into 2nd or 3rd gear with driveshaft. No driveshaft, purrs like a kitten. On the road it doesn't sound anything like the noise. Put a pipe to the cover of each differential to listen and only hear a low humming noise like everything is fine. Both front and rear sound the same.
- Remove accessory belt and couldn't find anything suspect
- Removed auxiliary fan which squeaks when pushed - no change
- Front pinion nut is tight, not leaking
I first thought I heard the noise after I changed the carrier bearings/axle seals but my memory could be off on that. I was coming back from vacation including some light wheeling with a friend. I didn't touch the pinion during the repair.
Any ideas on how I can determine the cause of this noise?
- Tried removing front driveshaft - no difference
- Tried swapping each wheel bearing with a spare, and each tire with a spare - no difference
- Inspected front and rear brakes; found rear left adjuster may have been grooving the brake drum. No change after repair
- Ran on jack stands up to 40MPH in 2wd, 4wd, with front and rear driveshafts alternately removed and both removed - don't really hear it! What I do hear is a god awful noise from the transmission when it shifts into 2nd or 3rd gear with driveshaft. No driveshaft, purrs like a kitten. On the road it doesn't sound anything like the noise. Put a pipe to the cover of each differential to listen and only hear a low humming noise like everything is fine. Both front and rear sound the same.
- Remove accessory belt and couldn't find anything suspect
- Removed auxiliary fan which squeaks when pushed - no change
- Front pinion nut is tight, not leaking
I first thought I heard the noise after I changed the carrier bearings/axle seals but my memory could be off on that. I was coming back from vacation including some light wheeling with a friend. I didn't touch the pinion during the repair.
Any ideas on how I can determine the cause of this noise?