well without specific model/serial number i couldnt give exact info even if i had it, but i can speak in general terms.

if you have a zf axle it may have multiple wet disk brakes living inside the final drives, if this is the case you will need standard gear oil with a friction additive. a zf driveline dealer will be able to get you zf's house brand. you can ask that dealer how often to change the oil, but if forced to guess i would say between 800/1000 hrs between changes should suffice.

tovel is a very small company loacted not far from a company i used to work for. as with most small equipment makes, their machines are just a collection of parts from various manufacturers... they simply dont build enough trucks to be able to tender custom driveline parts designs from zf/dana/etc. all major components are off-the-shelf and any custom weldments and small parts can be easily duplicated by small fab shops. so you are by no means tied to the dealer... except perhaps for curved glass pieces on cab-equipped telehandlers

just find a component parts dealer appropriate to the driveline part you are working on, and give the data tag/plate information from the component and you are good to go e.g. perkins, dana, voith/zf, clark, gresen etc.

there was a run of tovels years ago that used WWII surplus drive axles mfd. by FWD (four-wheel-drive) co. and they reserved a small quantity of axle assemblies for spare parts

they had a complex multi-piston floating disk brake system that cost a bomb to overhaul because everything had to be duplicated by fabricators... the disks, pistons, even the friction pucks... calipers had to be sleeved if they wore out... what a nightmare