My truck is bucking when taking offHelp.....

Help..... I just bought a Freighter....

Bobtail started out great.
Empty side dumper when letting out in first gear as it engages it shudders a little till im rolling

With 25 ton load on any kind of incline it bucks like crazy!!

If I am on downward incline it starts out normal

It seems to be getting slowly worse.... If I cant get moving you can see my problem. this is only starting from dead stop.

All the trucks ive driven let out on steep incline and away they go.
Whats worn?
What needs adjustment?

The clutch begins to engage about 1 inch of pedal push
No grinding of gears going into gear.

Linkage?? meaning clutch is not engaging soon enough take up some space??

Help gotta move dirt again tomorrow