Yup, another vibrations thread. I've searched and read on and off for months now.
Info: np242 xcase, 4.5 in short arm zone add a leaf kit(had good upcountry rear springs) IRO hack n tap, d30 front, 8.25 rear.
Well, after having a 4.5in lift kit from zone, everything seemed fine until I installed a Hack 'n Tap SYE, and yes, I shimmed the rear pinion within 1 or 2 degrees of pointing straight at the yoke of the TC. At the very same time, I replaced the front axle U joints, which the old ones were shot. Like rust and dust falling out when I took them apart.
These vibrations are terrible at 60 mph that are audible and shake the entire rig.
So, with the install if the SYE, I took out the xcase drop brackets. I drove it on the freeway. Bad vibrations resulted. I then looked at pinion angle in the rear and installed correct shims. Vibes still present. Looked at front pinion angles, which were off. I have no adjustable upper control arms, so I reinstallled xcase drop brackets. Still vibrations. I took out the front drive shaft and the vibes are gone. I then swapped the one I took out for the one in the rear, still leaving the front drive shaft out. No vibes. Now using the drive shaft that was originally in the rear, I put it up front and the vibes are just as bad as before with both in. I checked all u joints, they are good. I've checked for slop in pinions, all are tight. Xcase yokes have no slop.
The weird thing is that I had no vibes at all before I changed to a SYE and did the front axle u joints. Is it possible that a wheel bearing was going bad, and now with all of the slop gone from bad front axle u joints, that maybe it's getting magnified? I've jacked up the front and checked for play multiple times, all seems well. I'm at a loss. I've swapped in known good driveshafts with no luck. This problem is driving me nuts. I almost feel like installing a stock xcase with the slip yoke back on it just to better diagnose this, but I don't think that is the issue.
Any help is greatly appreciated. It's driving me crazy! Just want to run at 70 with little to no vibes! Thanks all in advance!
Info: np242 xcase, 4.5 in short arm zone add a leaf kit(had good upcountry rear springs) IRO hack n tap, d30 front, 8.25 rear.
Well, after having a 4.5in lift kit from zone, everything seemed fine until I installed a Hack 'n Tap SYE, and yes, I shimmed the rear pinion within 1 or 2 degrees of pointing straight at the yoke of the TC. At the very same time, I replaced the front axle U joints, which the old ones were shot. Like rust and dust falling out when I took them apart.
These vibrations are terrible at 60 mph that are audible and shake the entire rig.
So, with the install if the SYE, I took out the xcase drop brackets. I drove it on the freeway. Bad vibrations resulted. I then looked at pinion angle in the rear and installed correct shims. Vibes still present. Looked at front pinion angles, which were off. I have no adjustable upper control arms, so I reinstallled xcase drop brackets. Still vibrations. I took out the front drive shaft and the vibes are gone. I then swapped the one I took out for the one in the rear, still leaving the front drive shaft out. No vibes. Now using the drive shaft that was originally in the rear, I put it up front and the vibes are just as bad as before with both in. I checked all u joints, they are good. I've checked for slop in pinions, all are tight. Xcase yokes have no slop.
The weird thing is that I had no vibes at all before I changed to a SYE and did the front axle u joints. Is it possible that a wheel bearing was going bad, and now with all of the slop gone from bad front axle u joints, that maybe it's getting magnified? I've jacked up the front and checked for play multiple times, all seems well. I'm at a loss. I've swapped in known good driveshafts with no luck. This problem is driving me nuts. I almost feel like installing a stock xcase with the slip yoke back on it just to better diagnose this, but I don't think that is the issue.
Any help is greatly appreciated. It's driving me crazy! Just want to run at 70 with little to no vibes! Thanks all in advance!
