Front end noise in 4wd

[GJolicoeur]

I have a 04. 5, 3500 4X4 with 45,000 miles on it. I use 4wd a lot on wet, snowy and slick pavement. I don't hesitate to drive at 60-70 mph in 4wd.

I've developed this winter a "bearing" noise that I can only hear on acceleration in 4wd. It works in time with the speed of the wheel - so I'm left with wondering if it's a wheel bearing, a u-joint or both?

I've done all the u-joints in the driveshafts - just the front axle left. But I don't want to go crazy on the front joints if I also have to do the wheel bearings.

Any advice - some way to troubleshoot the actual problem before tearing down?

 

[mclunas]

have you jacked up the tires and tried to get play top to bottom left to right

 

[Smokey 01]

I had the same type of noise and it was a bad joint in the front driveshaft. I didn't catch it in time and I had to replace the whole shaft.

 

[GJolicoeur]

I just replaced all 3 joints in the front driveshaft about a month ago. Also, the noise thrums in time with the speed of the wheel, not at about 4 times the speed like the driveshaft. I'll jack it up and check for play as soon as we dig out of the snow that's falling and drifting. I need to determine if it's the u-joint or the wheel bearing, or both.

Is it possible to get the hub off without separating the bearing?

 

[Smokey 01]

It has a unitized bearing assembly, so it's one piece. The hardest part of dissassembling it is getting the bearing out because it gets seized. If you have air tools and good hand tools you can easily take it apart and have it back together in two hours. It sounds like when these bearings fail they go bad quick. If it's the axle joint it should be worse when you are turning or have it under a heavy load. Good luck in finding your problem.

 

[cojhl2]

I have a 04. 5, 3500 4X4 with 45,000 miles on it. I use 4wd a lot on wet, snowy and slick pavement. I don't hesitate to drive at 60-70 mph in 4wd.

I've developed this winter a "bearing" noise that I can only hear on acceleration in 4wd. It works in time with the speed of the wheel - so I'm left with wondering if it's a wheel bearing, a u-joint or both?

I've done all the u-joints in the driveshafts - just the front axle left. But I don't want to go crazy on the front joints if I also have to do the wheel bearings.

Any advice - some way to troubleshoot the actual problem before tearing down?

Because it's only under acceleration I would guess a U-Joint.

 

[GJolicoeur]

Well, I changed out the right front u-joint and was surprised to find it in good condition.



I couldn't get the hub off with a hammer or my air hammer, so I used the power steering method with a socket and extension. Since the bolts have a shoulder - this worked in 5 minutes without drama.



It's getting low on lubricant, but all the crosses were wet with grease and no signs of wear. I installed the Precision 464 - it's superior to the stock joints - heavier and a grease fitting!



I checked the hub bearing on and off the truck (jacked the tire with a 2 X 4) - no play whatsoever, but when I spin it on it's side (the way it sits in the truck) it's perfectly smooth. If I lay it down (the way torque would pull on it in 4wd) and turn it, I can feel some light knocking. Have I found the problem or is that normal?



I'm going to strap a microphone on the axle at boths ends and go for a drive. Hopefully, I'll clearly hear the source of the sound.