B2400 HSD Bi-Speed Turn Gear Case Fluid?

[GPW]

Hi All,
Had to replace the axle on a B2400 with Bi-Speed turning.
I can not find a reference to the type or amount of oil to put back in the case.
Hydraulic or 90W. The only plug I find is on the bottom. How full do I fill it? There is no link to any other fluid system on the tractor.
Any help is appreciated.
Dj

 

[GPW]

Soo, About a min after I hit the button, I got a call back from Messick's tech support.
Maybe this will help someone else.
The bi-Speed gear case uses the 90w and is actually linked to the axle. I guess it takes a good hr to get from the axle to the gear case, so don't go driving away to quickly. They estimated about 2 gal of oil between the axle and gear box. I am going to prefill the gear box before installing it.
Hope this helps someone.
Dj