d21 navara diff or hubs not working

hi all im new to the forum
i have a 1990 d21 navara double cab
its on 33s and has a non turbo 2.7diesel
the prob i have is its not going into 4x4 how do i tell if its the front diff or hubs ?
i got it home after a 3hour drive after buying it to find the hubs locked in 4x4 if i drive it with them unlocked it makes a rubbing -vibrating noise from them
any help would be good thanks

Hi,
Welcome to the forum.

If you want to diagnose a 4wd fault, you can do what i did today (if your mec minded / otherwise get someone to do it for you).

Jackup the car so the wheels arent on the ground, put it on 4 heavy duty jackstands, or more if you have them (or a hoyst). Turn the car on, put it in 4l, 1st gear and have a look see if your fronts are spinning.

If they are spinning then your getting 4wd fine.

If they arent, firstly check that the gearbox to diff shaft is spinning. If its not you proberly have an issue with the transfer case.

If this is spinning, check that the two diff outputs are spinning. If these arent spinning, then you have my current issue, a busted front diff.

If the diff is rotating the Cv's but your wheels arent moving then I guess you have an issue with your front Hubs.

I would have to stress at this point that it is verry dangerious to have the car in gear above the ground. Insure you have heavy duity car stands placed on the chasis rail / somewhere important. Dont try to make the wheels spin fast, just like a rc car your car will move with the momentium of your wheels so you run the risk of it vibrating/falling of the stands and landing on yourself/your friend or driving into something important.

If your not sure, dont do it.

as for the vibrating - im unsure. I would expect there to be excess vibration when the hubs are locked, not when they are in the free position. This could possibly be your hubs/brake components.

Goodluck,
Christian