Front driveshaft causing vibration, not the driveshaft itself
I have been trying to get to the bottom of this problem for a month now, and sadly have made little progress. Any advice would be greatly appreciated.
Back story: Clicking developed when turning and braking. Naturally I replaced both front cv axles. Didn't change anything. Next I took out the front driveshaft. Drove around the block, no clicking at all. Grabbed an exact driveshaft from a U-Pull It yard. Shaft was the same length as the one I had. Put it in.
Current Problem: Vehicle vibrates at speeds above 60mph (not as bad as a death wobble, but enough). Vibrations started about 300 miles ago, I've been easy on it since. May be coincidence, but after a 70mile trip at 59mph (and once or twice hitting vibrations speeds), came to a stop to find a terrible burning differential smell, with fluid leaking out both sides of the front axle and a bunch of "whining" noise. I was able to "tip toe" it home. Took the driveshaft to driveshaft shop. Guys looked at it and said its not the problem, the driveshaft is perfectly fine. On the way home, left the driveshaft out, and found the vibration is non existent at 60.
Short: Replaced driveshaft with a used U-Pull it. Vehicle vibrates above 60, has leaked some differential fluid out sides of axle. Took driveshaft out, vibration is gone. Took the driveshaft to driveline shop, and they looked at it and said its more than fine.
Vehicle: 1995 ZJ 5.2L V8. 249 TC. 138,000
1995 ZJ Limited
5.2 V8, NP249