Jcb 3cx no drive

Hi all, my backhoe has a problem of no forward or reverse drive and was wondering if anyone would have a clue as to why. It was working fine and all of a sudden nothing. The next day when I was to fix it, it worked again very sluggishly for about ten minutes then no drive again.
Fluid levels are good and I have power to the solenoids on the gearbox and can hear them engage.
Would a transmission filter chance be worth it, probably hasn't had one for a long time

First thing if you have power to your solenoids even when you lost drive this would indicate a problem in the gearbox.
Is this a powershift or sychro shuttle gearbox( only 2 solenoids ) Need to do pressure test on the mail line as well.
If as you say the solenoids are energized and you can here something in the box trying I would suggest dropping the oil out via the oval plate held on with two 13 mm headed bolts you will need a oil tray about 15 ltrs or so and see what you have on you pick up strainer this will either be metal (bearing /shaft/g box casing)or fibre material (clutch pack fault) possible blue nylon bits (clutch pack seals).

Hi Ronthefordfan inspect the neutal solenoid take out and reviews that solenoid realy works.