I was changing my oil today and noticed some evidence of an oil leak/seepage on the drivers side as pictured below. The truck has about 130k miles on it, runs great and I've always used Mobil 1 from day one.
Any ideas where the oil could be leaking from? Anything to worry about?
I remember changing spark plugs a while ago and one of the plugs had some oil on the threads, can't remember which one though. That shock only has about 1,000 miles on it believe it or not.