90 dodge power ram 4 wheel drive won't engage
 

Hi my name is mike and i have a 90 power ram and would like to know why when i put my truck in 4 wheel drive it won't engage to the front wheels...it seems to b engaging through the transfere case but wheels won't turn...kinda new to 4 wheel drive...help would b appreicated

Does the truck have manual or automatic locking hubs? I know my 92 has automatic locking hubs but some guys like to switch to manual locking hubs..

For future reference:
https://dodgeforum.com/forum/dodge-r...s-section.html

sounds like the 2 piece axle , actuator is not working, you can swap a 1 piece axle and manual hubs . but u have to install the proper axle seal for the 1 piece axle

Hi Mike. Welcome to the forum. Look on top of the front differential drivers side axle tube down by the drivers feet. You will probably find a vacuum motor. This devise engages the axles to connect the two wheels. It takes the place of locking hubs. Is it there? If it is we can talk you thru the trouble shooting procedure but we must know what we are working on.

It has automatic locking hubs...is it better to have auto or manual?

Since you are new to 4x4 operation I must ask this. Are you positive that you have locking hubs or might you have the locking axle system which is also automatic. The locking axle system is the norm. If you aren't sure look on top of the front differential drivers side axle tube down by the drivers feet for the vacuum motor. This devise engages the axles to connect the two wheels. It would also mean you have hubs that are mechanically locked to the axle shafts.

If you have auto hubs I would recommend replacing them with manual hubs as the auto ones that Dodge used tend to be complicated and unreliable.

To go along with what Seal said...if you go ahead and replace the hubs with manual hubs you should also consider removing\de-activating the CAD system and locking the actuator on the front axle or replace the shaft with a 1-piece. Since even with manual locking hubs if the CAD system fails in any way you would still not have 4wd.

IF you do have the CAD though manual hubs arent going to really do anything for you. But chances are if you have the CAD system something is going wrong there because it shouldnt be your hubs because they are full time, not auto or manual, that is unless someone changed them.

damn, this whole vacuum operated vs manual hubs thing just confuses me to death, if i sorta kinda got it figured my transfer case sends power to my front diff, but unless the vacuum thing is working properly then I'm not really in 4wd, if the vacuum thing is working properley then in my truck it sends power to 1 of the front wheels because i have no posi. I don't have anything to lock or unlock on the end of each axle so i have automatic hubs? or fully locked hubs?
I don't understand why they just didn't make the front axle the same as the back axle...what am i missing is there a point to all this hocus pocus?