al2ride

Just picked up a really nice 98 XJ manual 4x4 with 80k miles on it. It runs great but I've started to notice a couple of things. There is a bit of noise coming from either tranny or transfer case. Usually on 5th gear you can hear a bit of a rattle, and yesterday I pressed hard on the gas while on 5th and it kinda thumped, but never got out of gear. Another thing I've noticed is a bit of clunking noise while engaging clutch in between changing gears...not sure if this is the pilot bearing, or differential play. The u-joints look in pretty good shape. I'm going to change both tranny and transfer case oil. what is the best recommendation as far as oil for both. I also just put new rubber 235/75r15 and was looking into doing a little bit of a lift...maybe 1.5"...I know there are a plethora of options out there. Would like to hear which way works best for the money. Thanks in advance.