[tcfco2005]

So i just bought a 99 ford ranger 4x4 with a 4.0 and manual
Im new to trucks and 4x4 so im not too sure on what is going on...Well what happens is when i try to go backward whether it be in gear or in nuetral my front tires will lock up on me...they get a little turn then they lock up...i can go forwards with no problem but right when i go backwards...its all lock...if i force it they just slide...i know thats probably not the smartest thing to do but i was pissed...So what can it be...i did a little searching here and i see that the 99's have shitty automatic hubs could it be the hubs messing up...im a totally newb to trucks so any help or suggestions would be great...Thanks