QX4 rumble

[RogQX4]

My 2002 QX4 w/ 187000 miles has a rumble/vibration that starts at 40 mph. I can remove the front drive shaft and there's no noise at any speed. I replaced the
u-joints but still have the noise. Does the transfer case internal parts rotate in 2wd? Thanks!

[atraudes]

Just a guess, but it sounds like the front driveshaft needs to be balanced or replaced. The driveshaft is hard-wired to the wheels, so it rotates when they do. The disconnect between your front wheels and the transmission happens in the transfer case. I'm not sure where precisely in the transfer case, but everything's moving at all times so the wheels can be engaged immediately, even while in motion.

I think I know the answer to this already, but does the vibration get better or worse when in 4WD vs 2WD?

[Jsteele69]

I have a 1998 infiniti QX4 with about 192000 on the clock, it has a vibration from about 35/40 miles per hour.I just replaced the front wheel bearings,because I was told that was more than likely the cause,guess what,not!
I saw this post and said that sounds like my problem,but I haven't taken the front drive shaft off yet.
I was wondering if you had to replace the drive shaft? If so how much was it? And did that solve the problem?
Any feed back would be much appreciated,if I can't fix this problem we are going to need to get a different vehicle,I think there is still a bunch of life left in said ride.