jeep noise

Ever since I hade my slave cylinder channged my jeep has been makeing a matalic spinning noise it sounds like its comeing from the engine/bellhousing/transmission area though I know sounds can be deceiving. The noise is all the time and wasmt there when I bought it. Its hard to hear when driving so at first I thought it was only happening when coasting 7n neutral or with the clutch pressed in but then I decided to pay more attention and noticed it while driving. It does not happen while idling.

Some background info, 90 yj 4 cyl soa lift. 30" tires I am assuming wernt ballanced I have a feeling when I bought it he took his 31's off and and swapped them for the 30's on his tj he bought to replace it. Rear diff leaks and there appears to be a leak near the rear of the trans and has 300+ km on the origional engine, well taken care of with regualar maitence and just started ticking 2 weeks ago which im pretty sure is a sticky lifter. Any ideas and detailed info on how to check/test what could be causing this noise would be great. Im not to concerned about the tire ballancing right now as I have 35's to put on, I bought am 8.8 with the brackets mounted on I just saveing up to get the little odds and ends that will need replacing.

Cheers, Gungnir.