I've got a rumble that seems to be coming from either d/s wheel area or tranny/clutch area. This is a 4wd D/R manual. I've had u-joints go bad on other cars before and the sound is similar. Pushing in the clutch has no effect on the noise. Pushing on the brakes has no effect. Cornering at any speed has no effect. The rumble is in any gear. Strange thing is the sound will appear then disappear intermittently with no obvious changes. For instance, I was driving the PA turnpike the other day, criuising along at a constant speed and rpm on a straight section of road and the noise would appear then disappear. Sometimes the noise appears for many minutes (say 20-30) then disappear, and sometimes the on/off cycle is just a few seconds in duration. I would compare the on/off cycle to a light with a loose electrical connection; completely random.

do you feel vibration? is it in your seat or in the steering wheel?

 

a whwwl bearing noise will go away when you turn one way or another. a loose axle nut noise will go away when you hit the brakes(generally)

 

a bad cv joint will pop and click while turning, and sometimes jerk the wheel

 

a bad doj(double 0ffset joint-inner axle joint at tranny) will vibrate through the steering wheel most times, and you may feel it in the seat. generally when the doj makes noise it will start on acceleration and go away on decel, or vice versa.

 

how do the axle boots look?

The only place that I can notice vibration is in the pedals/floor area. I can't really feel any vibration in the steering wheel (apart from the slight amount of "normal" vibration in the steering wheel). Boots look good. I replaced the d/s axle less than 10,000 miles ago (no offroading) with a reman unit from Autozone. The sound only occurs when the car is in motion. I have been trying to make it rumble by pushing on brakes, pushing in clutch, cornering, accelerating, using 4wd, etc. Nothing that I do starts or stops the rumble. It seems to be completely random. Sounds similar to running the engine with the air cleaner off and the pipes exposed (the pipes in the system that introduce air and have the silencers in them). Is there any way to test the axles? Can I remove one side and drive around the block?