Power Major 3 Pt. Hitch Problems

I have a Power Major ( 1961 ). The 3 Point hitch will lift and hold, but is useless at powering down i.e, It will not drive a plow into the ground, only allows it to "float". Can anyone offer any suggestions as to what causes this problem. Also, does the 3 point hitch hydraulics, ( and the front blade attachment hydraulics) use the same oil as the final drive lubricant? It seems as though it does, but if so, what is the recommended oil for the final drive compartment?
Would appreciate any replies. Thanks.
Les Taylor, Brisbane, Australia

Thanks for the follow up, and the information.

Regards,

Les

Just use Universal Tractor Oil for the gearbox and diff. Watch out for the oil level in the gearbox, quite often the seal goes between the gearbox and diff and the oil runs out of the gearbox and the level gets higher in the rear end.

Steven B Oh yes, thanks for the photo, looks like a good project. Those rear guards have been painted grey, they should be blue. I like the blade.