Dually wheel help please!
 

Sorry if this is a simple answer that I just cant see. I recently purchased a new to me 98 k3500 dually 7.4. I noticed anything over about 35-40 there is a vibration that feels like the tires need balanced. Removed the wheels tonight at work to balance them. When i removed the wheels I believe I discovered the reason for the vibration. The truck came with what i believe is aftermarket wheels, they are aluminum wheels that have a shank style lug nut. The inside wheels in the rear are still the factory style steel wheels. Where i am confused is how the steel wheels are supposed to be centered. I know the aluminum wheels use the lug nuts to center, but the steel wheel on the inside just rest on the stud allowing it to be slightly off to one side. What I am wondering is what i need to center the inside wheel and how were they centered from the factory. I have been searching for hours and have no answers. How are aftermarket wheels usually centered? Thanks and sorry for the overly complicated question.

The inside wheels should have a center ring to center them

Thanks In2Trux. I did a lot of digging on this subject and think I might have come up with something. Chevy dually wheels are supposed to be hub centric and not need a ring. The wheel on the truck is far from hub centric, there is about a 1/8 inch gap between the wheel and hub. I have also found out that dodge wheels have a larger center bore but same bolt pattern. Not sure why but I belive the previous owner may have put dodge wheels on the inside in the rear that are lug centric. So hopefully I can just buy a couple of factory chevy wheels and correct this. Everything I have found says the factory wheels should not need a centering ring.

That's great news. I'm glad you were able to find that. Hopefully a OEM rim will fix the issue.
If can't find anybody with a set on Craig's List and if the Dealership or tire shop want too $$$ Maybe try an Auto Recycler Center (Auto Wrecker)

Good luck.
Keep us updated.
Thanks for coming back and sharing

Thanks trux, I found some on ebay for 65 each shipped. I'll keep you posted on how it turns out.