I picked up another D250 yesterday. Thought the rear hubs looked odd, but couldn't put my finger on it.

Now I see the difference. The '90 D250 that I already have (08/89 production) has hubs that are bell shaped. The hub is full diameter at the hub flange, and gets skinnier going back to the wheel mounting surface.

This 'new' 90 D250 (11/89 production) has constant-diameter hubs i.e. full diameter right back to the wheel mounting surface.

Both have 1/2" wheel studs and are SRW trucks. Both axles use studs and cones to retain the shafts. Any reason for the difference? Any particular style preferable for any reason?

 

There are a whole host of hub variations in the DANA line-up; many are interchangable, regardless of being Dana-60, -70, or whatever, although they may appear different.

My neighbor spun a wheel-bearing somewhere in Nebraska way back when his 1993 cab-chassis Dana-70 DRW 4x4 was nearly new.

The guy at the filling-station where he limped to took him to an ancient old junk-yard and got an entirely different-looking hub off of an old SRW Dana-60 that was under an old gas-burner truck.

He swapped the wheel-studs; and, seeing as it was a Sunday way out in nowhere, cleaned up and used the old bearings that were in that old antique hub.

To this very day, that hub and those bearings are still going strong, as I parked beside the truck and sat across the table from him at lunch.