I've noticed for a long time now that I've been leaking something. When I put headers on my truck, I pulled the oil dipstick out of the block, and ever since then, it hasn't been in right. I thought all the spots where I park at were from oil leaking out, but I noticed that my rear end cover was wet at the bottom. I smelled the stuff on the ground and it was gear lube. I've noticed a clicking noise in the rear axle area when I'm driving slow. Could this have anything to do with my problem? Has anyone else had a problem like this?