'72 GMC Split Rim Question

[harrydunn]

I was taking a look at my split rims today to do some touch-up and was curious (yet again) what my options may be as far as a one-piece, 8-lug, 16" GM rim. I'm not sure if I'll do it yet but it's been on my mind quite a bit. SPID says "7.5-16.0-6 PR HIGH." The tires are in great shape (235/85-16") and I'd like to swap them over, so I'm not interested in 16.5" rims. I'd also like to be able to pop my hubcaps right on. I'd keep the original split rims in storage. What specific rims do I need to be looking for to keep it factory in appearance?

Also, I was surprised to read "tubeless" on the side of the tire. I figured split rims required tubes. Perhaps I misread that somewhere.

Thanks for your help!

--Mark

[Stocker]

The tires are tubeless, but split rims (and locking-ring wheels) do require tubes and liners.

There are plenty of late-model OEM wheels that will work for you.... not so sure about steelies that will take your hubcaps, though.

[special-K]

The 16" rims from GM Trucks through '87 are great. They were used through '91 on Suburbans and Crewcabs. All the hubcap style outer nub-type 8-lugs from any truck will work with your hubcaps. All the hubcaps interchange. You see Ford hubcaps on Dodges and dodge hubcaps on Chevys and GMC hubcaps on Internationals

[morgan71]

Hey, nice looking wheels there. I got my wheels from a mid 70's to 70's 3/4 ton chevrolet truck. Hubcaps fit without issue.

[harrydunn]

I'm assuming I'll need to stick with GM rims so they are hubcentric, yes?

Thanks.

[Stocker]

Originally Posted by harrydunn

I'm assuming I'll need to stick with GM rims so they are hubcentric, yes?

Thanks.

I have been running non-hubcentric aftermarket wheels since removing my split rims about 30 years ago. No issues.

[special-K]

Not necessarily,but that's where it gets tricky. It would be safest/easiest to use wheels you know are GM,but I am 99.9% sure Dodges are the same and at least some Fords.

[harrydunn]

I'll start hitting up the local salvage yards this week.

[Stocker]

Originally Posted by special-K

I am 99.9% sure Dodges are the same and at least some Fords.

Yes, Dodge is same 8 x 6.5 and so is Ford until 1999 when they changed to 8 x 170mm.

[harrydunn]

Originally Posted by Stocker

Yes, Dodge is same 8 x 6.5 and so is Ford until 1999 when they changed to 8 x 170mm.

"6.5" here refers to the lug offset I'm assuming? Still learning about these trucks. I've owned it a little under 3 months now.

[Stocker]

6.5" is the distance from the center of any lug to the center of the lug directly across from it -- that is, the farthest distance, center-to-center, between any two lugs.

[ETsC10]

Not to look like a ditz but what is hubcentric?

[special-K]

It means the weight bearing on the hubs,not just the studs. The hole in the wheel fits snug on the hub. I never worried about it and never had a problem. This is what I was referring to in my last post,not lug pattern. I know they all are the same,except when Ford went metric. I believe the whole hubcentric thing is from the '70 & earlier one tons that had flat back lugs and wheels were not chamfered. But,I ran a '70 C/30 with aftermarket chrome Budds and never had a problem. The wheels,of course,were drilled for 9/16" studs,too.

[1972K20]

Special-k, are you talking about semi-floating/full-floating axles when you say "hubcentric?"

[Frkypunk70]

Are split rims even legal? I remember my dad and I replaced the split rims on his 67 1 ton dump in the late 80's and I seem to remember there was some issue with it being illegal. Might just be my state. I also remember they were dangerous as hell.

[tcb-1]

Originally Posted by 1972K20

Special-k, are you talking about semi-floating/full-floating axles when you say "hubcentric?"

I'll jump if for you, Tim.

the term "hubcentric" has nothing to do with the axle per se. it refers to the centering characteristic of a rim. most older vehicles were lug centric, which meant the theoretic centerline of the wheel was based on the lug nuts centering the rim itself on the axle.

hubcentric rims have a closer tolerance center hole that centers the rim on the axle hub. the lug nuts do not center the rim, the hub to rim fit does.

[Frkypunk70]

Sorry did not mean to get off subject. I was thinking aloud (and somehow typing).

[tcb-1]

Originally Posted by Frkypunk70

Sorry did not mean to get off subject. I was thinking aloud (and somehow typing).

not off subject at all, partner....

split rims are illegal in several states. and yes, the are as dangerous as hell. I knew a guy back around 1980 that had half of his face removed from one. they are dangerous, yes, but can be serviced safely with a proper cage setup.

however with that said, I have always been an admirer of the splits. nothing says work like a set of splits and 8 plys.

[Stocker]

Originally Posted by tcb-1

split rims are illegal in several states. and yes, the are as dangerous as hell. I knew a guy back around 1980 that had half of his face removed from one. they are dangerous, yes, but can be serviced safely with a proper cage setup.

Learn something every day.... I did not know they were illegal anywhere. I know they can be deadly if not handled properly. That said, I have seen a lot of them changed on a concrete floor with no cage, by guys who did it every day, usually on big stuff for semi trucks.

[mr48chev]

Originally Posted by Stocker

Learn something every day.... I did not know they were illegal anywhere. I know they can be deadly if not handled properly. That said, I have seen a lot of them changed on a concrete floor with no cage, by guys who did it every day, usually on big stuff for semi trucks.

While they may not be illegal as the law goes the majority of tire shops won't work on them anymore due to the safety issues for their workers in the tire shop. If you were to look at the cages they have to air them up in you would see that the bars in most of those cages are bent where the ring came off the rim inside the cage when it was being aired up. The guy I bought tires from in the early 70's got killed when he didn't put one in a cage and it took the top of his head off when he aired it up and the ring blew off.

[Frkypunk70]

I call my dad and ask him what he used. If it was available in the late 80's it would be easy to find a that cheap replacement today.

[Frkypunk70]

Well I called him and he used ambulance wheels from later model but said he had trouble with the holes for the lugs being oversized and cut spacers out of pipe that filled the void. (sounds as dangerous as split rims) LOL

[tcb-1]

stocker,
I think I am going to back off the statement that splits are illegal. I did a little research and did not find anything concrete to tell me that they are indeed illegal..... so for the sake of sticking my foot in my mouth, don't trust me.

however, that still does not say that it will be hard to find a service shop that will touch them. it's a major liability that the shop will just wouldn't want to cover.

[Spoof]

I was shooting the bull a few months back, talking about the worst injury or call we've ever seen. The f.fighter next to me said it was a rim/tire explosion during an air fill, the tech. was half gone, the rest of him was all over the shop.
Just sayin...

[harrydunn]

I may have found a set of one-piece 8-lug wheels close by. They are off of an '86 Chevy 2500 (photo below). Will the back-spacing be okay from an '86? I can't remember the cut-off year. Looks like my hubcaps should fit right up.

Also, they are only a 6.5" rim. My split rims are 7.5" running 235/85R16 tires. Is a 6.5" rim too narrow for this tire size? Seems like it could be.

I've got a forum member who may have a set for me if these don't work out.

Thanks.