Lubricant for P/S box conversion.

Aug 16, 2020
Need some advice. I'm converting the P/S box of 4x4 Nissan to be used as a idler arm. Input shaft has been removed as will gearing, only the idler shaft will remain. Should I use the gear oil or maybe engine oil for bearing lubrication opposed to the originally used ATF since there won't be pressurised lubrication any more? Tnx in advance.
One place I used to work at had a bunch of gear boxes. Non pressurized and low speed operation. They had all those filled with Mobil 1 20W50 motorcycle oil, and never any issues, defects, debris, or shavings. About 10-15oz per gearbox, getting changed once in 5 years, unless an oil seal gives up earlier. Even in 5 years of 24/7/365 operation oil is still golden clean, just a darker shade of gold VS new oil. Lack of high temp and/or combustion byproducts help.