hub center bore; newer vs. older

[curtis73]

I was reading the wheel tech article here and researching on some other sites and came up with a question.

Most wheel reference sites list the center bore of all Ranger wheels from the 80s up to the latest as being 70.6mm (or 70.3 or 70.5 depending on the site), but the tech article here says that late-model wheels won't fit on the front of my 94 because the hub bore is too small for the 4x4 hubs.

Is my assumption correct that the hub bore on the inside where it meets the rotor is still the correct 70.6mm, but the hub bore steps down smaller toward the outside? So I would need to enlarge the outside of the hub bore, but the inside where it meets the hub is still going to be correct? (oh, and I doubt it makes a difference, but I ditched the busted auto locking hubs for manual hubs from an earlier truck)

Going from these 15x7 wheels on my 94 B4000:

To these 16x7 wheels from an 05 Ranger:

 

[adsm08]

I once had a chance to test fit a set of FX4 Alcoas on my 87, and they went on just fine.

The later rims you pictured were originally for an Explorer, and they have a very small center hole. I would try fitting just a 4x4 hub through if you can, and see how it fits.

If it doesn't you should be able to get a brake cylinder or small engine hone and open the hole up enough yourself.

 

[curtis73]

That was my thought as well. Thanks.

 

[Uncle Gump]

I have that very wheel on my 06... it's a no go on the earlier models. It won't go on over the lockout hub. I think most all of the 16 inch wheels are the same.

 

[adsm08]

I have that very wheel on my 06... it's a no go on the earlier models. It won't go on over the lockout hub. I think most all of the 16 inch wheels are the same.

Yeah, that's the wheel that was on my 05 Explorer, and like I said, that center hole is tiny.

 

[curtis73]

So here's the answer. Yes, both appear to have the same hub bore on the inside where it centers on the hub, but the newer wheels have a significant lip that will need to get cut away. I think it's a bit more than a hone will do. I think I need to add about 3/8" diameter to the outside of the hub bore.

I might have a big enough mill bit for the drill press. If not, off to the machine shop.

Old wheel shown mounted to the truck (you can see the lug nuts), new wheel shown with the bigger lip inside the bore.

 

[curtis73]

So, fun update. I did a bunch of checking things with calipers. I called a couple machine shops just in case it would be affordable and all three said they wouldn't touch it... liability, yadda yadda.

So I decided to have some fun. Turns out, a carbide flush cut router bit with an oversized guide bearing works perfectly on aluminum.

Here is the later (05) wheel showing the lip that needs to be removed.

Here is how I set up the flush cut bit.

Go a little bit at a time and use a lubricant. WD40 works well for aluminum, but I used cutting oil. To my surprise, there was very little smoke, and after the whole job the bit was only warm. You'll see one divot in my cut at about 10 o'clock in the photo. I suggest checking your guide bearing frequently. Mine fell off, I'm assuming due to the increased vibes from the hard aluminum. I used the oversized bearing for two reasons; 1) The hole didn't need to be any bigger, and 2) I wanted a little lip so the rear center caps had something to snap into.

The completed cut:

Then one coat of etching primer and two coats of flat black later:

 

[alwaysFlOoReD]

Nice job and great innovating!

 

[curtis73]

Thanks. 265/75-16 tires ordered. I got the Continental TerrainContact AT based on reviews. I'll let you know how I like them. My off-roading is minimal and mostly rocks with a little mud. 90% of what I need is wet and snow on roads so I hope they're a good choice for a lighter AT that doesn't make too much noise on the road.