Hi, I hope someone can help me out here.
My 1998 Tacoma 4WD has about 55,000 miles on it. A thousand or so miles back it developed a low-frequency rumble that varied only with road speed. It was most noticable between 35 and 45 mph, but was also audible at highway speeds. The vibration is constant through turns and leans, but it does vary when driving through a dip as the vehicle squats down on the suspension.
This morning I drove the truck and the rumble turned into a definite vibration at 70-85 mph. It does not behave like an out-of-balance tire. I believe it to be U-joints or the double cardan joint, but could also be the transmission output bearing, the drive shaft splines, or the differential input bearing. Any suggestions how I might isolate the problem? My visual inspection showed no signs of rust or loose joints.
My 1998 Tacoma 4WD has about 55,000 miles on it. A thousand or so miles back it developed a low-frequency rumble that varied only with road speed. It was most noticable between 35 and 45 mph, but was also audible at highway speeds. The vibration is constant through turns and leans, but it does vary when driving through a dip as the vehicle squats down on the suspension.
This morning I drove the truck and the rumble turned into a definite vibration at 70-85 mph. It does not behave like an out-of-balance tire. I believe it to be U-joints or the double cardan joint, but could also be the transmission output bearing, the drive shaft splines, or the differential input bearing. Any suggestions how I might isolate the problem? My visual inspection showed no signs of rust or loose joints.