My rear main seal is leaking. I have read that this is a tough job. My mechanic wants $500. My question is along the lines of what type of damage can occur if I do not replace it yet. It is leaking pretty good - in that it leaves a small puddle of oil after each drive - but not good enough to change the fluid level on the dipstick after 3K miles. Planning a family trip to CO the first week of August and was hoping to keep the $500 for some fun. What do you all think? Can I just keep checking the dipstick and go or are there other issues?