Grease specified in ring and pinion gear on flail mower?

[jthorner]

I have a large Ford 917 tractor PTO powered flail mover which uses a ring and pinion style reduction gearbox to both make a right angle turn and to reduce speed between the driveshaft and the driven rotor.

Recently while doing maintenance I removed the cover from the gearcase (much like a solid automotive rear axle diff) I drained the gear lube which was in there.

Much to my surprise when I looked in the owner's manual it called for grease as the service fill, not gear oil. Hmmm, it seems to me that in a closed case like that gear oil would do a better job than grease.

I refilled with 85W-140 gear oil. Should I switch over to grease? I am inclined to keep using gear oil as the gears and bearings were in good shape when I inspected them and I saw no signs of it ever having been filled with grease.

John

 

[Kestas]

My gut feeling tells me that gear oil should be okay, even preferred. There is more assurance that you get a film of lubricant where it's needed when you use oil. Plus relubrication is much easier... when it's easier you do it more often!

 

[brian fix]

I think 80-140 would be fine,what brand did you use?