coastalBend - 3/21/2019 08:22 80w90 from autozone or cheapest distributor. Been running mine since 2011. When i got it the hub seals leaked and had to speedy sleeve the spindles. Had to redo seals last season, so had machine shop build up and cut new surface. I change it once per year. If u remove the hubs, the planet gears have to be timed. After u assemble it spin it several times in each direction without the wheel motor engaged. It should spin free, if it binds up, its wrong. If u have a machine shop cut the spindle, measure the shoulder very carefully and warn them. If its too tall or short it will effect the hub. front and rear are different internals but spindle and housing are the same.