What would you do? 99 WJ Jeep GC 4.0. Both rear axle seals have been leaky for years but the rate seems to have increased to about a loss of 1 qt/year (10K miles). The oil stops at the diff-side back plate of the rotors but doesn't contaminate the rotors/brake pads. I don't mind putting in the time and work involved in the repair but overall cost of repair is a factor. This vehicle has about 250K, a salvage title from a collision, and a fair market value of about $800. To do the repair, I would need to cut off old wheel bearings and buy new bearings + seals and to use a shop press. I priced the parts from RA, using National brand parts. WJB budget parts are much cheaper. If I can find a shop that is willing to press the bearings for me for $20/bearing, cost would come out to about $100. If I buy my own shop press from HF, cost would be around $170. Or would you just keep adding gear oil yearly? It has 80W-90 right now. Would 85W-140 slow the leak? 4 quarts of Super Tech 80W90 or 85W140 costs about $14. Other than environmental, are there other downsides of just keep adding oil?