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Dakota guys:
I have a '92 Dak Club Cab with the 2-piece drive shaft. a 46RH at one end, and a stock 3.55 rear gear at the other. NO MODS TO SUSPENSION. its stock height. and stock wheels/tires.
Ever since my 46RH tranny was replaced i get a vibration at 70 to 90 MPH. the vibration matches wheel speed. i can feel it when i put my hand on the cab floor near the "hump" or drive shaft tunnel. and i can also hear it faintly. put truck in neutral while at highway speed and the vibration is still there. as truck slows down, the tone of the vibration gets lower and lower. ( its like a faint drone sound ) so i know it driveline or rear gear.
other work done at the same time as tranny was the u-joints. all of them.
i took the truck back to the shop and the checked driveshaft angles. they found that the driveshaft angles were about 3 degrees off and they corrected it by inserting some spacers between tranny mount and frame. now the drive shaft angles are within 1 degree
of perfect. they also looked for any weights on the driveshafts that may have gotten lost. they are all there. looked for dents. no dents in shaft.
but the vibration is still there. so, what can it be? rear gear backlash -or- that drive shaft center support bearing?
when you push up and down on the driveshaft near the center support bearing should it be able to move? or should it be pretty well fixed in one location within the bearing?
p.s. the driveshafts, rear gear and axles are all original from manufacturer.
-dan
I have a '92 Dak Club Cab with the 2-piece drive shaft. a 46RH at one end, and a stock 3.55 rear gear at the other. NO MODS TO SUSPENSION. its stock height. and stock wheels/tires.
Ever since my 46RH tranny was replaced i get a vibration at 70 to 90 MPH. the vibration matches wheel speed. i can feel it when i put my hand on the cab floor near the "hump" or drive shaft tunnel. and i can also hear it faintly. put truck in neutral while at highway speed and the vibration is still there. as truck slows down, the tone of the vibration gets lower and lower. ( its like a faint drone sound ) so i know it driveline or rear gear.
other work done at the same time as tranny was the u-joints. all of them.
i took the truck back to the shop and the checked driveshaft angles. they found that the driveshaft angles were about 3 degrees off and they corrected it by inserting some spacers between tranny mount and frame. now the drive shaft angles are within 1 degree
of perfect. they also looked for any weights on the driveshafts that may have gotten lost. they are all there. looked for dents. no dents in shaft.
but the vibration is still there. so, what can it be? rear gear backlash -or- that drive shaft center support bearing?
when you push up and down on the driveshaft near the center support bearing should it be able to move? or should it be pretty well fixed in one location within the bearing?
p.s. the driveshafts, rear gear and axles are all original from manufacturer.
-dan