Had that trouble on my 955L, transmission pump was getting bad. The oil was pushing into or drawing into the steering clutch pump thus filling the clutch case up and lowering the transmission oil. The steering clutch pump is bolted on the back and driven off the trans pump.
can a moderator remove this post please.
Don't see how, the 49J is a direct drive. Trans and bevel gear is all one compartment.
Ah! your right mag! must be the bevel gear seal then.
Bevel gear seal would leak into the steering clutch compartment.
No oil level to check there, dry steering clutches and brakes.
Time to drain the steering clutch compartment????