I have a vibration in CJ-5, I have a 304 with a T-150 and Dana 20. I get a vibration in the Jeep only in 3rd gear, I took out the rear drive shaft thinking the u-joint where bad, they were OK. While I had the shaft out I drove it on the front and had no vibrations. I have rebuilt the Dana 20 with all new bearings and mid shaft, no luck the vibration is still there. My big ? is why only in 3rd gear and I cannot feel the vibration in the shifter on eather the tranny or T-case, the vibration seems to come through the floor boards.