Auto matic hubs won't stay in

[8cylRWD]

My 94 ranger with 4.0/automatic has 'automatic hubs'. I have thoroughly cleaned them when I repacked the wheel bearings last winter, and they actually worke for the first time in the four years I've had the truck. Didn't see anything that looked damaged or worn. I cleaned then and lightly lubed them with ATF before reassembly. However today I went to use the truck to pull out some sizeable shrubbery and they would not stay engaged, When I gassed on it the rear wheels would just start to spin and the front hub made a ratcheting noise. The owners manual says no snowplow use for this vehicle, and I've been told by told local guys that these truck are only made to use 4wd in the snow or loose dirt or mud, but not for work purposes.
What's the story? Should I spend the $$ and put manual hubs on it, but is it strong enough to stand up the the input torque? Thanks

 

[scotts90ranger]

auto hubs on these are notoriously bad, manual hubs will take whatever you throw at them... Ok, there are people that break them with stock size tires, but manuals are stronger than autos. AllanD on here is or was selling two hubs with the needed jam nuts for $90, best deal you'll find in a quick manner (getting lucky and finding a good set in the junk yard is hard sometimes)

 

[4x4junkie]

If you want a set of true workhorse hubs, look for the Warn pt# 37780 Jeep hubs.
However, chances are the standard Warn hubs (#29071) will suffice quite well if you're not running oversized tires on your truck.

http://www.therangerstation.com/Magazine/May04/offroad.htm

 

[8cylRWD]

What's the trick to ID'ing a 28 vs 35?? Truck has 4.0/Auto. Frt Axle weight rating unknown, shown as 2740 lb. with factory tires on door jamb tag. (The people that determine ID tags for these light duty trucks really need to take a lesson from the big-rig boys, that is put the actual axle rating on the spec tag, along with the mfr and model). thanks

 

[scotts90ranger]

if you have a 4.0, you have a dana 35. a dana 35 has 10 bolts holding the pumpkin on the front of the drivers side beam and the dana 28 has 12 bolts if you are looking in the junk yard, thats good enough of an identification for hubs

 

[8cylRWD]

Thanks