Oil for rotary mower gearbox

[aarolar]

What oil s needed for a rotary mower gearbox? I bought my gearbox and built my deck and frame so I have no manual. Will just any good gear oil suffice?

 

[SSdoxie]

I would use an 80W/90 gear lube.

 

[davesl708]

My mower gearbox uses 80/90 as SSdoxie recommended.

 

[aarolar]

Figured thanks

 

[LD1]

Yep, any good gear oil.

I use 85/140 on one of mine, and 00 grease in another. Light weight grease is usually okay too.

 

[Copperhead]

Yep, 80w90 or 75w90 synthetic. I usually have the latter on hand because of commercial truck use.

 

[Texasmark]

Yep, 80w90 or 75w90 synthetic. I usually have the latter on hand because of commercial truck use.

I like the synthetic too on new ones. I put it in and forget about it. On new ones (and surely upper end old ones) I like the fact that OEMs have started using ventilating fill plugs which allow the gearbox to breathe and take the pressure off the output shaft seal. Going to bet that a lot of current leakers wouldn't be leaking if the pressure was allowed to vent when it builds up.......for those reading and wanting one rather than the conventional ½" pipe plug, auto parts stores carry them, especially the neighborhood mom and pop shops in farming communities.

 

[aarolar]

I like the synthetic too on new ones. I put it in and forget about it. On new ones (and surely upper end old ones) I like the fact that OEMs have started using ventilating fill plugs which allow the gearbox to breathe and take the pressure off the output shaft seal. Going to bet that a lot of current leakers wouldn't be leaking if the pressure was allowed to vent when it builds up.......for those reading and wanting one rather than the conventional ½" pipe plug, auto parts stores carry them, especially the neighborhood mom and pop shops in farming communities.

Thanks for the idea