I have an oil leak in Yukon with 277,000 miles. I'm not sure if it's coming from the rear main seal or the rear part of the oil pan gasket or if there is a gasket at the oil filter adapter. The rear main seal was changed with a NAPA brand at about 245,000 miles when I put in a reman transmission. I cannot pinpoint where the leak is coming from even after power washing it clean. I'm losing about just over a quart of oil every 3000 miles. The oil seems to be dripping right where the oil filter is even above it, I just change the oil today too. The whole oil filter is usually soaked as well as the bottom bell housing of the transmission . Last oil change prior I swapped out the oil cooler block off plate gasket with no effect. Has anybody had any issues like this? I'm tired of the large oil spot on my driveway, but I don't mind the rust proofing underneath the truck, LOL.