aplchn_mtngoat
NAXJA Forum User
- Location
- Lehigh Valley, PA
Hey all, I'm looking for some advice on troubleshooting a potentially bad gearing setup in my D30 axle. 4.56 G2 gears, Detroit TrueTrac. I have a weird rumble style vibration clearly noticeable at speeds above 40mph, and very slightly noticeable at 15mph and up. I have tried, but cannot get it on video. I'm very positive it follows wheel speed rotation, not driveshaft rotation. The noise also changes when steering, as one wheel rotation varies from the opposite side, and at higher speeds like a sharp exit ramp, the noise almost, oddly, seems to disappear. It is not affected by acceleration/deceleration load whatsoever, only speed. I put the Jeep on stands, supporting the axle, and the noise was completely gone, despite changing out the hubs for good ones. This makes me think it is absolutely the gears, such as when the forward motion of the Jeep is forcing the carrier to spin.
I originally thought I screwed up the pinion preload and redid the pinion with new bearings and shims, but the noise didn't change one bit. I thoroughly went through the front end, ended up replacing both hubs and putting in new shafts, all which never changed the noise. I went further on and troubleshooted the driveshafts and rear axle shafts (almost everything that rotates - as a dummy check), all with no change. Note, when I redid the pinion the backlash increased from 0.007 to 0.010. I'm wondering if my carrier bearings perhaps are bad or if I didn't set enough preload on it, or perhaps if my pinion depth is too deep. I will include a picture of my setup pattern. I really don't want to tear into the gears again for it to not do anything, and would really appreciate some outside opinions.
I originally thought I screwed up the pinion preload and redid the pinion with new bearings and shims, but the noise didn't change one bit. I thoroughly went through the front end, ended up replacing both hubs and putting in new shafts, all which never changed the noise. I went further on and troubleshooted the driveshafts and rear axle shafts (almost everything that rotates - as a dummy check), all with no change. Note, when I redid the pinion the backlash increased from 0.007 to 0.010. I'm wondering if my carrier bearings perhaps are bad or if I didn't set enough preload on it, or perhaps if my pinion depth is too deep. I will include a picture of my setup pattern. I really don't want to tear into the gears again for it to not do anything, and would really appreciate some outside opinions.
