First post, fighting a huge issue with harmonic vibration and wrecking transfer case bearings. I've replaced u-joints, balanced shafts, on my third rebuilt t-case from Transfer case Express, and now this one looks like it may now be junk at about 400 miles. The vibration come on at around 63 and worsen slightly with increasing speeds, increased vibes when acceleration under loads or going up hills. We just arrived for the 4th after driving 190 miles and I noticed it the driveline started howling at around 65-70 like a pinion bearing or something. Upon arrival the transfer case was so hot you could not touch it more that 1/2 a second and seeping oil from the front and rear shaft seals...Also tried 4 hi lock briefly and it made some groaning scraping noises when turning and it was binding up. Didn't want to move without hitting the gas. I have gone through everything, driveshafts are checked for runout and indexed for the smoothest operation. I have put new solid bushings in the front differential just before the trip. Made no difference in vibration. If you pull the front shaft and run it in 4 hi lock, vibes are completely gone. I have checked the front driveshaft angles and see a big problem that can't be fixed so chime in if your trucks are the same. The front driveshaft u-joints are in the wrong plane, opposing each other. The front transfer case angles upward, the front diff angles upward also. The front diff should parallel the transfer case pointing down correct??? This looks like the cause of constant vibes.

It’s a 2006 with 127,000 on it now. All stock. Tires are within 2/10” diameter, center tread is very close to even on all 4, outer edges of fronts are slightly smaller. That was a question from others with awd tranfer case issues. Don’t know what other pics you want.