In Reply to: grease instead of 80/90 wt oil in gear box posted by Ronald on August 25, 2020 at 20:43:12:
Works in the short term but will ruin the gears in the long term.
Gears are case hardened and need EP additive to protect the thin hardened layer.
No EP additive in chassis lube.
If your gearbox seals are not totally gone, you can use CNH Pourable HI EP oil. It is about the consistency of 00 grease and is loaded with EP additive.
Available from CNH but your dealer may need to order it.