Information on changing wheels from 16.5" to 16"

My 1979 Brougham originally came with 16.5" dually wheels and 8.00-16.5" tires. This size tire was very common back in the day but harder to find now. Most of what you can get now are oddball brands with questionable quality, and most tire shops do not keep them in stock. I decided to check into changing to 16" wheels so I could use a more common size of tire. The new tire size is 225/75R-16. These tires are about an inch larger in overall diameter than the originals. Another advantage of switching to 16" tires is that most tire stores have them in stock in case you have a problem away from home. Below you can see what the camper looked like before and after the wheel change.

Below are what the wheels look like close up. The white wheel is the 16.5" and the black is the 16". The 16" wheels can come from Dodge trucks and vans up to 1993. You can also use ones from Ford trucks up to 1982 but you may have to drill a new locator hole in the wheel. Some replacement wheels had oval locating holes that fit both Dodge and Ford. The wheel width is 6" and the bolt circle is 6.5", sometimes listed as 165.1 mm.

In the picture below you can see that the 16.5" wheel (right) has a sort of bell shaped center where the 16" one (left) has a globe shape. Another advantage of the 16" wheels is that they are a safety rim design that has a ridge to retain the tire bead when installed. This means if you have a flat, the tire is less likely to come loose from the wheel.

An important thing to know when changing the wheels is that Dodge duallies up to 1993 require "coined" wheels. This refers to the design of the wheel around the wheel stud holes. Every other hole has a raised "coin" around it. The other holes are dished. This is how they make the wheels line up properly on the vehicle. The hubs on the vehicle have recesses around the wheel studs and when the wheels are mounted the coins on the wheel fit these recesses. On the rear where the two wheels fit together, the coins interlock to keep the wheels from shifting around. Dodge used a large flanged lug nut that fits over the raised coins and keeps everything lined up. Fords seemed to use 90 degree tapered lug nuts but the same wheel design. Beware that using wheels without the coins may cause damage to the wheels and the vehicle. Wheels like that are intended for vehicles there the center hole of the rim fits over the hub on the vehicle to line them up and for support. The picture below is of a universal replacement 16" wheel. You can see the raised and recessed coins on this wheel. You can also see the oval locator hole.

Here is the front hub on the camper before I rebuilt the brakes. You can see the recesses around the studs where the coins from the wheel fit in. The front wheels don't use a locating pin. The rears do so that you can't accidentally put the two wheels on wrong.

Below are shown the flanged lug nuts required to mount dual wheels on Dodge trucks and vans. The flange fits over the coined area on the wheels to securely clamp the wheel to the hub. These nuts require 325 ft. lbs. of torque so make sure you have a stout socket and breaker bar and probably a pipe extension to get them on and off.

Here are additional pictures showing the tires I used on the Brougham. The polished stainless steel covers are called "wheel simulators". They are held on by the lug nuts. Some cheaper ones snap on to the rim like an automotive wheel cover but these could fly off while driving down the road. Simulators can be found at tire stores or online. I bought these from Ebay. I cleaned up the wheels and painted them with black rust preventative paint before mounting them to the camper.

Main Brougham page
Engine and Transmission
Installing the Fiamma F45i Awning
Replacing the Ceiling