Differential Lock.
how do you take the boom cylinder apart on a john deere 310c backhoe
I tried to paste but unable due to being in pdf files, just google timing specs for john deere 310 and it should guide you to the pdf
To remove the rear axle from a 1996 John Deere 310D backhoe, first ensure the machine is securely supported and the hydraulic system is depressurized. Disconnect the drive shafts and any hydraulic lines connected to the axle. Remove the mounting bolts securing the axle to the frame, then carefully slide the axle out of position. It's important to refer to the service manual for any specific torque specifications and procedures.
Your hydraulic fluid level is low, your hyd. pump is weak, your hyd. filter needs replacing, there is a spring release that is activated by hydraulic pressure under the machine, above the transaxle, if it does not receive enough hydrulic pressure, it will not release completely..
There are two fuel filters specified by FRAM for this vehicle. A square FRAM P1130A and a round PS7408A
Ouch! this could be a problem. I would start by looking for a Bentleys guide. You may need to contact Mercedes directly or a repair shop for a wiring diagram.