Rumbling when hubs are locked

My 1995 taco sounds like I’m driving on rumble strips
Only when the hubs are locked
And only when slowing down
(Without breaking)
It stops the second I give it gas
It dose this in 4wd
In 2wd it just rumbles no matter what when the Hubs are locked
Non of my mechanic friends can figure it out what could it be???

 

when have you last changed the wheel bearings?

 

I’ve only owned it for a few months so i don’t know the last time it was fully maintained

 

Well.. Start simple. Pull the front drive shaft and see if that changes anything. I shouldn't be spinning at all with the hubs unlocked in 2wd. No change = something in the front drive line.

With manual hubs, you can actually pull the CV's and drive it (for those reading in the future, you CANNOT drive an ADD truck without the CV axles, the wheels will fall off). If you still have a rumble without the cvs, then it's something in the hubs. If there is not a rumble, then it might be something in the front diff.

 

Have you checked if the hubs are actually locking, or if they’re getting stuck in some intermediate position?

 

Thanks !! I’ll start with that

 

I assume they are locking because they function as when I lock them but idk if they could be slipping??