I recently pulled my rearend and installed a locker and new gears. I would like to change the gear oil after 500 miles. Can I put a tube in the filler whole and suck it out or is loosening the whole 3rd member the only way? Some people say there is no need to change it but others say I should, do I need to change it? After about 100 miles I checked the level and it was a little full, the oil that came out had a metallic luster to it.