How do I check the hub fluid or whatever is in them on the 99 4x4 scrambler?

 

There is an allen key plug on the hub itself. You should take the plug out then turn the wheel until the plug hole is in the 4 O’clock or 8 O’clock position. If fluid starts coming out you are good. If not, add fluid slowly until it comes out. Use the Polaris hub fluid. Some people use automotive synthetic automatic trans fluid. If it hasn’t been changed you may want to just drain it all the way out and add new fluid