A random question about diffs.

[feellnfroggy]

I was doing my front axle and I began to wonder. Why cant wheel bearing grease be used on differential bearings and gears? To avoid the whole filling messy diff fluid thing?

 

[rangerbum]

The viscosity difference. The oil climbs the gears and circulates, grease would fling off, and stay nicely packed on the housing, not the gears. Could be wrong, but that's what I see happening.

 

[strvger]

had an old scout once that leaked the fluid out of the manual steering gear box. drained the box and replaced the fluid with the synthetic blue color lower marine lube. worked great and never leaked again. didn't get any more stiff in winter temps either.
some things you can get away with, some things not. no, i wouldn't try doing that in axles. as above, you need the lube on the gears, not the inside of the housing.

 

[satan]

the biggest thing (besides the pressure being a lot higer in the ring/pinion) is that the hypoid cut to gears produces a wiping motion accross the face of the gears -- any paste lube would work-away from the contact surfaces by the first revolution of the gear.

The splash-bath/climbing lube properties will "reapply" lubrication for each revolution of the gearset, so that it can be wiped again and again.

Additional benefits of a liquid lube is the related thermal mass and circulation/dissipation of heat.

Kinda stuff like that y'know ?

 

[lumpy4000]

the biggest thing (besides the pressure being a lot higer in the ring/pinion) is that the hypoid cut to gears produces a wiping motion accross the face of the gears -- any paste lube would work-away from the contact surfaces by the first revolution of the gear.

The splash-bath/climbing lube properties will "reapply" lubrication for each revolution of the gearset, so that it can be wiped again and again.

Additional benefits of a liquid lube is the related thermal mass and circulation/dissipation of heat.

Kinda stuff like that y'know ?

the part about the thermal properties of gear oil helping to cool the ring and pinion..... probably most important. go for an hour drive on a nice warm day, pull over, and put your hand on the diff cover, you might find it "kinda" warm, and thats with proper lubrication.

 

[feellnfroggy]

the part about the thermal properties of gear oil helping to cool the ring and pinion..... probably most important. go for an hour drive on a nice warm day, pull over, and put your hand on the diff cover, you might find it "kinda" warm, and thats with proper lubrication.

I normally wouldnt say this, but I was tending to think like Satan when I posted the question, LOL> I didnt do it, I was just curious. I didnt think about the wiping motion good point.

As for the thermal properties, Im not so sure about, not near the frictional resistance on the diff like there is on wheel bearings is there? The diff spins fast, but the wheel bearings have the whole weight of the truck,