Been dealing with a bad vibration on my truck for a while. Spent all kinds of time trying to balance the tires. Never thought that the problem was coming from my driveshaft. The U-joint on the rear of the drive shaft was completely waisted. Only took about 45 minutes tops to fix. the old U-joint was shot, now for the question. Was it a bad idea to replace it with a non greasable u-joint it was a cheapy from autozone but it definetly did the trick. Just wondering if anybody else has done this.