Calling the BFF brains trust.
Was removing old fence posts, lifting them with a chain on the lift arms. Some were resisting almost to the limit of the system. There was a quiet "bang" & the lift arms went instantly to the ground. With the engine at idle, there is a very unpleasant sounding, quiet "thump, thump, thump" at about engine speed coming from the nether regions. :-(.
P.t.o. still turns.
Auxilliary pump still pumps oil (thru an open port, at zero pressure).
Tractor still moves.
Thus: gearbox is ok; p.t.o. (& linkage pump) shaft is not broken.
An internal hydraulic fitting may have blown - but why the thumping, which does not sound like the relief valve.
Q. 1. Is it safe to drive 500m home or should I get it towed (thinking of bits of metal moving to unwanted places here) ?
Q.2. Any guesses about what might have failed?
All suggestions welcomed.
JV