I have used off terrain forklifts but new to 3 wheel truck forklifts. The one my work got is a older used piggyback. Its actually a 1996 D5000. I'm curious about 2 things about the machine.
1st- it has 2 buttons for 3wd. I know they make the 3rd wheel work. But I don't know which button does what. But if I am in spot and need more torque, pushing both gives me that extra torque. What are those 2 buttons supposed to do?

2nd- when those buttons are pushed and it's in 2wd, it goes faster on pavement. But randomly it feels like the 3rd wheel might lock up for a moment. And then go back to normal and do it again maybe every 60 seconds or so. Or if I turn tight on the road to line up to side of the truck.

Any ideas would be great.