FSM calls for grease, gear oil would just leak out. Most of us do not run the amount of grease that the FSM calls for because of the mess when you have to change out on the trail!!!!!doc_sausage said:seriously, would 80-90 gear oil be what really goes in the axle, or is this so you can change the birf's w/o oil spillage.
Neat idea for a street rig driven in the dirt occasionally but on a trail rig unnecessary in my opinion. When I was running birfs I would pack the birf by filling the axle hole with grease and shove a short side axle in to it pushing the grease into the inside of the birf. Repeating it until the grease is coming out all the way around the balls of the birf. Then before I would install it, I would wipe the outside of the bell with about 1/8 inch of grease. You keep pumping grease into the knuckle, when you do blow a birf you will have a big mess to clean up and a lot of times it ends up somewhere on our trails in the bushes!!!!! Before you put the knuckle on pack the trunion bearings just like you do the wheel bearings. :grinpimp:Here's a really cheap trick, that can be done anytime, but is easy while you have the axle torn down. Pull those square plugs on the knuckle housing (you know the ones you try to pump grease into, not gear oil, right) and drill and tap a hole for a grease fitting. I installed a 45°angled grease Zerk in each plug and now its easy to shoot a little extra grease into the knuckle if needed. With the crossover steering arms in the way, access to those plugs is limited, but its easy to pop a grease gun on the Zerk.