Case IH 1680 hydrostatic quit in the field

[jerrycook_]

just started beans with my 1980s Case IH 1680 and the hydro just quit moving. the head still lifts and the auger swings out fine, and the reservoir is full, so I know I haven't lost all hydraulics.
I’m hearing a weird, mild grinding sound coming from high above the left rear tire
is it possible that the splines on the hydro pump drive gave out? it happened all at once while heading up a slight grade

if those main splines spun, would I still have steering and header lift, or am I looking at something else?
thoughts?

 

[Shedmechanic]

That sounds familiar, I had a similar issue with my 1680 hydro once. When the pump drive splines slipped, I completely lost hydro, which meant no lift or steering. Since yours is still able to lift the head and swing the auger, I think it could be something else, maybe a control valve or some linkage problem.

 

[Rustinpeace]

Dealt with a similar problem on my old Case IH. If the main pump splines were shot, you wouldn't have any movement at all. Since some functions are still working, it might be worth checking the hydro linkage or the pump bearings those grinding noises could be coming from there.

 

[redpowerop]

I dealt with a hydro failure like this a few seasons ago. A total spline failure took everything out, but the fact that your header and auger are still moving suggests it could be an issue with the pump shaft or maybe a stuck relief valve. That noise could give you more info