Truth about dually tires rubbing each other

[curtis73]

I've heard that dually tires touching is a really bad thing, and I understand how it could be... sorta
Anyway the long story is I got a freebie chevy dually with 10-year-old 7.50x16 flat tires. I replaced them with some good used 235/85-16 and the rears are darn close to touching. I'm sure they'll touch with a load on. Can they touch a little, not at all, how much space is safe?

[Fiat48]

You don't want them rubbing. Someone should make a wheel spacer that would solve that. Use no more thickness than you need and make sure both sides of the spacer is completly flat AND full diameter. If you cannot find something...have a machinest make you a couple aluminum spacers.

[curtis73]

I'll try that, but I only have about three threads showing on the studs. I don't think there is enough space there to add enough of a spacer to do any good.
I've seen spacers that bolt on and then have their own studs, but I can't imagine they would retain the weight capacity.

[JetBoatRich]

I've seen spacers that bolt on and then have their own studs, but I can't imagine they would retain the weight capacity.
I have these, no problems :cool:

[curtis73]

http://i15.ebayimg.com/06/i/07/e6/15/58_1.JPG
Do you have something like this?
Here's my whole thought process from two weeks of working on this problem.
Simple spacers: I only have three threads showing above the nut, so I could only space about 1/8". I could install longer studs, but these are 30-year-old drums and I've been told that pressing old studs out is completely out of the question on 14-bolt drums. So I could get new drums since I can get them wholesale, but they're still over $120 each plus the longer studs if I can find them.
Skinnier tires: since the original tire is a 7.50x16, its a 32" diameter. The 235/85 closely matches that at about 31.9. The 215/85 is a mere 30". Not too big of a deal, but the next big problem with 215s is that they're D-range, not E. Some would do OK, but with a GVW of 11,800 some would be barely on target (especially since I like overkill). Then the third problem with 215s is that they are an incredibly uncommon size. I'd have to buy them new ($90 each at cost) which would be $650 until you add shipping and mounting.
Bolt on spacers (like above) have to be really thick, like at least 1.5" and that's too much. That would rub my fenders big time.
Jetboatrich... so does the order of your installation go like this: inner wheel, spacer over the studs, lug nuts on the spacer, outer wheel on the spacer studs, then lug nuts? Are your wheels acorned? The problem with my wheels (since they're made to install in any position) is they don't have any acorns and if I space them they won't be hubcentric.
Grrrr. I was hoping for an easy solution, but it seems like this is all so impossible.

[JetBoatRich]

http://i15.ebayimg.com/06/i/07/e6/15/58_1.JPG
Do you have something like this?
Jetboatrich... so does the order of your installation go like this: inner wheel, spacer over the studs, lug nuts on the spacer, outer wheel on the spacer studs, then lug nuts? Are your wheels acorned? The problem with my wheels (since they're made to install in any position) is they don't have any acorns and if I space them they won't be hubcentric.
Grrrr. I was hoping for an easy solution, but it seems like this is all so impossible.
Yes, that is how there are installed. No problem with rubbing withe 35's, look at the picture below
http://www.***boat.com/image_center/data/520/78Steph_835.jpg

[Fiat48]

I'll try that, but I only have about three threads showing on the studs. I don't think there is enough space there to add enough of a spacer to do any good.
I've seen spacers that bolt on and then have their own studs, but I can't imagine they would retain the weight capacity.
Something is up with that. Not the right studs or was not a dually in the first place.

[curtis73]

Oh, it was definitely a dually. I'm well versed in 14-bolts. Absolutely no doubt about it. I'll get you a picture later of everything installed. the lug studs are 1-1/4" long (same as other early 14-bolts) and the wheels are made of 1/4" steel. That leaves 3/4" for the retainer ring and lug nuts.
Keep in mind also, this is a commercial chassis which has much beefier wheels involved.
Let me try and upload a picture I did. Its not to scale but humor me :) Open it in a new window and follow along.
The wheels are flat around the lug holes; no conical seats. The lug nuts are conical, so the retaining ring that goes on the outside has conical seats. Now also take note of the fact that only the very inner part of the hub has the little chamfer for the hubcentric part. Its exactly enough to center both wheels and no more.
So... spacing out the wheel will cause the second wheel to be off the chamfer and no longer centered. If the wheels had conical seats I'd do it since the acorns would center it on the lugs but I don't have that option.
So, another thought. Since these wheels are 1/4" thick, could I have a conical seat machined into the wheel? It wouldnt' need to be much, just maybe 1/4" chamfer that cuts into the wheel about 1/8"? Possible??

[jh4rt]

Hmmm... We used to run 235/85/16 on our dually without them rubbing. You should mount them and take pictures. With 80 lbs. of air, they should be fine. You don't want them to rub, but being close is ok, so long as they don't touch under load. We ran them on a 78 Chev Dually with stock wheels towing a boat with 1500# of tongue weight.

[curtis73]

I have some photos of the studs.
jh4rt, I'm starting to wonder if newer trucks had a larger offset to the wheels. These definitely rub. At rest, stripped bare interior, 80 psi, no gas tanks, these tires are about 1/8" apart on jackstands, 1/16" apart sitting on the ground. If I just reach up and hang on the bumper I can watch the space disappear between the sidewalls. They'll rub with 10 gallons of gas, let alone a 3000-lb payload.
This first photo is the whole drum assembly... definitely a dually. The second photo is the retainer ring. The third is a closeup of the drum showing the small shoulders on the hub that make it hubcentric. The last one shows how little threads are showing as installed.

[curtis73]

Here's a photo of the space between the tires installed. No gas tanks, no interior, stripped bare. Confirmed 80 psi.

[curtis73]

jetboatrich... I assume your wheels have conical seats? That will be the problem with mine.. I don't have conical seats, so there will be nothing to center the wheel.

[JetBoatRich]

jetboatrich... I assume your wheels have conical seats? That will be the problem with mine.. I don't have conical seats, so there will be nothing to center the wheel.
obviously you need to get them centered :rolleyes: go down to you local 4X shop and see what they can do

[curtis73]

4x4 shop... great idea. Hadn't thought of that!
Thanks

[JetBoatRich]

From your pictures you only need a little spacer, should be no big deal.
I am looking to buy another set, mine was purchased for when the truck is air-downed for the sand and still not touch. I feel it is a little to much space and I probably won't be needing to air-down like that.
Let me know what you decide :cool:

[Beer-30]

All looks normal to me, just trash the 16.5s. Ooooooold Skoooool. 16" steel OR aluminum duallies are easy to get a hold of. People are always putting on custom wheels, so there are take-offs around. Conical seats and proper spacing - plus proper tire sizes and options. I run 225/75s (stock size for mine) and run 8ply on the front and 10s on the rear. Studs look normal length to me. I have chrome lug nuts, to I don't know how much thread is actually inside the enclosure, but they run up quite a bit. More than enough. I'll see if I can get you a pic or two in the next two days.

[curtis73]

Uh... it already has 16s :)

[Beer-30]

Uh... it already has 16s :)
OOOOPPPSSS. My bad. I saw the 7.50, and forgot that they made those in 16 also. 16.5 was the standard for duallys back when "7.00s and 7.50s" were the usual thing.
I'll get a pic or two of mine ('98).

[Beer-30]

Ok. Here ya go.
Stock steel inside, KMC alums on front and rear (outsides). Stock studs. 225/75-R16s
And, EDIT, I re-read your first post and see that you put on 235/85s. Yes, they will almost touch empty, touch loaded (depending on load and tire pressure). They are a little big and knock too much off of the torque curve for me. If you put 235s on the TBI motored duallys, they would hardly get out of their own way. I stuck with 215/85s on my '89 (dropped 3/5) and stayed with 225s on my current one (dropped 5/8). The shorter tire keeps the torque up and they don't touch.
I took a lug nut off so you could see the stud length:
http://www.***boat.com/image_center/data/520/2433IMG_2724.JPG
http://www.***boat.com/image_center/data/520/2433IMG_2725.JPG

[curtis73]

nice truck and thanks for the pics.
The reason I went with 235s was because they match the diameter of the 7.50x16 perfectly. By spinning the tires and counting the driveshaft turns I discovered that this has 4.56s anyway. The 215/85s are a full 2" shorter diameter and I'd be concerned about RPMs and speedo accuracy.
Much appreciated for the help everyone. I think I'll just bite the bullet and start looking for 88-later rims

[Beer-30]

Ouch. 4.56s. With 4.10s, a 4L80E overdrive tranny and 225/75s, I am about 3000 at 80. Sounds like more of a short-to-the-lake-and-back kinda truck.

[Big Kahunaa]

Ok. Here ya go.
Stock steel inside, KMC alums on front and rear (outsides). Stock studs. 225/75-R16s
And, EDIT, I re-read your first post and see that you put on 235/85s. Yes, they will almost touch empty, touch loaded (depending on load and tire pressure). They are a little big and knock too much off of the torque curve for me. If you put 235s on the TBI motored duallys, they would hardly get out of their own way. I stuck with 215/85s on my '89 (dropped 3/5) and stayed with 225s on my current one (dropped 5/8). The shorter tire keeps the torque up and they don't touch.
I took a lug nut off so you could see the stud length:
http://www.***boat.com/image_center/data/520/2433IMG_2724.JPG
http://www.***boat.com/image_center/data/520/2433IMG_2725.JPG
my 95 ford has this same spacing with stock steel inside rim and stock alcoa outers

[curtis73]

Ouch. 4.56s. With 4.10s, a 4L80E overdrive tranny and 225/75s, I am about 3000 at 80. Sounds like more of a short-to-the-lake-and-back kinda truck.
Yep. I'll be at 3000 at about 63. That was par for the course in the day... take one beefy 4-bolt 350, castrate it with pathetic heads and cam so it only makes 130 hp, then make up for how pathetic it is by stuffing crazy gears in it. It was also from a time when 55 was the federal speed limit and its only turning 2600 then.
I kinda like the 4.56s There was an optional 5.14:1 :cry:

[Beer-30]

Mine will be for sale mid-year.

[BAE_557]

http://i15.ebayimg.com/06/i/07/e6/15/58_1.JPG
Who makes these and where can I get them?

[curtis73]

Not sure about quality, but Ebay has thousands of them in every size from 1/4" up to 4"
That's where I stole that photo; ebay.

[moneysucker]

If you are running aluminum rims, you should be running mag lugs not the lugs that came with the steel rims. That may be where some of the 3 thread problem can be solved. There are some places that do adaptors and spacers they advertise in Truckin' magazine and you should be able to find them easily. I am not sure how much space you arre looking to gain but with mag lugs and a set of spacers, you should be able to gain around an inch.

[Schiada Time]

Beer 30-When you get ready to sell that dually PM me. It would look great towing my mostly RED & white Schiada V-drive.
Thanks

[Beer-30]

I understand the order forms for the new HDs are at the dealerships. I am going to wait a little longer to order, a few more months, as I want the new one to be nice and clean for SEMA.
You will actually be 2nd in line, as I got a PM a few months ago from someone else on here that wants to be notified.
I'll keep you informed.
Thanks.

[Beer-30]

Shoot me a PM and I will put it with the other one to keep tabs on who is interested. I don't know if I would remember which thread your post was in.
Thanks again.

[JetBoatRich]

Think I have seen you around town.
Where is around town:confused: I drive it now and then:D

[New Login]

So those are stock width dually wheels and 35"s what is the width of your spacer ???

[JetBoatRich]

6" for now, I want to pick up smaller spacers. These were used to air down in sand and keep the tires from hitting. I rarely go in the sand:jawdrop:

[JetBoatRich]

Near L & 55w
I would say it is me then:D

[JetBoatRich]

I got my Rims after seeing yours, very nice.
I will have to look for your truck then:rolleyes:

[Emanon Performance Marine]

I am looking for 3/8" or 1/2" wheel spacers, discs. For 8 on 6.5" lugs. Does anyone know where I can find some ?
Thank you

[RidinRed]

I've heard that dually tires touching is a really bad thing, and I understand how it could be... sorta
Anyway the long story is I got a freebie chevy dually with 10-year-old 7.50x16 flat tires. I replaced them with some good used 235/85-16 and the rears are darn close to touching. I'm sure they'll touch with a load on. Can they touch a little, not at all, how much space is safe?
might it have been cab/chassis? I think they used differant rear end width (drum to drum). Wheel spacers are around or can be made. Just use good material. They will be thick enough for nuts to hold them on or u can use skinnier with longer studs. That is all I know of. Good luck

[Emanon Performance Marine]

Here are some spacers and adapters;
http://www.ezaccessory.com/Wheel_Spacers_s/27.htm

[Arizona Don]

235/85/16 should fit without problems, so I'm thinking that one or both of the pairs of rims you have are not offset deeply enough. Perhaps others on here could measure and post their offsets. Chevy stock steel rims have straight bored holes and are hub-centric rather than nut centric and have a nut-centric torque plate. I've got a steel spare in the back of my dually from an older model that I'll measure and update my post later.