Thanks to the following Bolters for their help with this article:
Mike Boteler (Mike B)
Grant Ensrud (heavyhauler)
Pat Ertel (Editor, Vintage Truck Magazine)
John Gott (42Chevy)
Spanky Hardy (Spanky)
Grigg Mullen Jr.
Scott Ward (48bigtrucks)
Lee Young (Archivist, American Truck Historical Society)
For My Big Bolt!
You are nearing the end of your Big Bolt project and want to get it on the road. But your tires have too many dry rot cracks and not enough tread. Maybe you don't want the bias ply, tubed tires anyway and want to upgrade to a tubeless radial. Many of us "Big Bolt" owners have wondered what modern (i.e., tubeless) wheels will fit our trucks. Here's Grigg with some info on how to find...
Note: This is the first installment of an article that will eventually cover all the medium duty trucks (1.5-ton & 2-ton conventional and COE), 'late '30's through '73. For starters, we're covering 3/4-ton through 2-ton AD trucks.
Nomenclature used in this article
"Tire" -- The rubber part with tread that is mounted on a wheel.
"Wheel" -- The steel or aluminum part that the tire is mounted to. Also commonly referred to as a "rim."
"Lug" -- The bolts that wheels are attached to on the ends of the axles. Also used in differentiating the bolt patterns on different wheels (i.e., 8-lug, 10-lug, etc). Interchangeable with the word "stud."
"Big Bolt" -- A Stovebolt.com nickname for 1.5-ton and larger GM trucks.
"Dually" -- From "Dual Rear Wheels." In modern usage, this term refers to 1-ton pickup (and larger) trucks with four wheels on the rear axle. Duallies (Editor's Note: This is the correct plural form, guys :) )don't give a truck added traction, but they do provide greater stability and capacity for heavier loads.
Don't confuse with "Tandem" (see next entry).
"Tandem" -- This refers to wheels and axles that are one in front of the other (not next to each other) as on 10-wheeled road tractors that have "tandem duals" on the back -- two rear axles with 4 tires each). Single wheeled tandems on trucks are rare and generally only seen on tactical military vehicles running "Super Singles." Most car hauler-type trailers that you would pull behind a pickup truck, for example, are tandem axles. Semi trailers have recently started using super single tandem applications, though.
"Tubeless Tire" -- First offered by Chevrolet in 1956 on 22.5-inch wheels. They were not popular at first, due to the nascent technology not being as durable as modern versions. Modern style (usually radial ply) tires used on contemporary vehicles, generally offering smoother ride and easier maintenance.
"Bias-Ply/Tubed tires" -- Older style tires that require tubes. Rugged but not as smooth riding as a modern radial tire. A fine tire set up for original/unmodified trucks. Up-engined or otherwise modified trucks built for highway speeds may prefer use of radial tires and appropriate wheels.
"Budd Wheels" -- Generically used when referring to wheels that bolt on with a central circle of studs on the hub (normal wheels). They can interchange front to back, inside to outside, etc. There are two different designs for mounting and centering wheels, “hub-piloted”, and “stud-piloted”. Still in use today on light, medium and heavy duty rigs in both mounting designs, although hub-piloted is becoming the most popular for big trucks.
"Stud-Piloted" -- True “Budd” wheels are stud-piloted self-centering. These wheels bolt to the hub using conical female surfaces in the wheel and matching conical nuts to fit one another snugly to support the weight of the truck in addition to centering the wheels to the hub (by way of the studs and nuts). Dual Budd wheels require two types of nuts, inner and outer, to hold the respective wheels in place. A single (like for the front axle) wheel usually has yet another different type of nut.
"Hub-Piloted" -- Look very similar to true Budd wheels, but with different mounting details. Hub-piloted wheels have an accurately machined hole in the very center of the wheel that fits snugly on a spigot machined on the hub, thereby centering the wheel to the hub. The lug nuts have a flat washer face and only serve to clamp the wheel to the hub; they do not center the wheel. This is the design we are talking about for the 10-lug Advanced Design Chevy big trucks.
"Dayton Wheels" -- Not really applicable to this discussion, but refers to a brand of cast spoke wheels with de-mountable rims. They were popular east of the Mississippi and used primarily on heavy duty trucks. Most tube-type Dayton wheels made since the 1950's are easily and directly replaceable with new tubeless rims. As always, check your measurements.
"Multi-piece wheels" -- Older style wheels that usual consist of a main wheel rim with a fixed tire flange on one side and a detachable flange on the other. As can be seen in the image, there are many different ways to lock in the detachable flange -- some work better than others, and one style -- the RH-5 center split (see below) is to be avoided. The multi-piece wheel is, perhaps, the oldest style of automotive wheel and was designed to make changing tires feasible out on the road with simpler tools. Today, they are found mostly on antique vehicles and some farm & construction equipment.
"Locking Ring/2-Piece" or "3-Piece Wheels" -- Older style multi-piece wheels that mount tubed bias-ply tires. The wheels on most AD Chevy trucks are the locking ring type. Not to be confused with center split 2-piece wheels (see below), They can be serviced by professionals and are still useable if in good condition. Most big truck tire centers and Ag shops will still work with these wheels.
"Split Rim wheels" -- These wheels should be avoided.This scan from the 1949 Budd Wheel catalog illustrates the different wheel types. The dangerous 2-piece "split rim" (also know as the "widow maker") is the Firestone Type RH-5. The dominant feature of the RH-5 is the attachment of its halves near the wheel's center line. This connection point has an overlapping raised band around the inside of the wheel. This band will be seen on all types of RH-5 wheels, whether Budd style or traditional drop-center light-truck wheels. These wheels can be hard to identify because you can’t really see how they are made while assembled. It’s easier to identify them by eliminating the other possible wheel types. They are not "Locking Ring," "2-Piece" or "3-Piece Wheels" because they don’t have an easily identifiable ring or rings on one side (lip) of the wheel. They are not singe piece tubeless wheels because they do not have a dropped center (where the tire bead goes to allow you to work it over the rim for installation or removal). RH-5 wheels became popular in the late '40's (with manufacturers...) and were used extensively throughout the '50's and '60's. They were last available from Budd in 1972 and from Kelsey-Hayes in 1976. Due to their design, they have not aged well.
DANGER -- Wheels split in the very middle should be avoided! -- DANGER
Don’t even try to put air in one that is low!
When we get an antique truck to restore or drive as is, almost invariably it will need to have its tires replaced as the tires found on most restoration "projects" are not only worn but dry rotted and cracked as well. We have two options: staying original and just replacing the original style tubed tires (assuming the wheels are still serviceable); or upgrading to modern tubeless tires and single piece wheels. We will focus on the available newer wheels and tubeless tires.
Most of the information I have is about the 10-lug wheels used on our AD (Advanced Design 1948-1954) trucks. Much of what I have learned comes from experience with AD trucks and reading the Accuride Wheel Catalog. Of particular interest is page 28 with the 10 lug on 7.25" circle and 5.25" center hole. This is the exact bolt pattern used on late AD 1.5 and 2 ton trucks. Earlier trucks have the same bolt pattern but a smaller 4.75” center hole, because of this the new Accuride wheels are not a direct replacement for trucks with this smaller hub diameter, we’ll get to the details and solutions later.
As a side note, Ford used the same bolt pattern with a larger 5.46" center hole on the F-Super Duty trucks from 88-97, available in a 16" rim. Because of the larger center hole these wheels are not directly useable on our Chevy trucks without bushings in the center holes, as the wheels are hub-piloted and it is important that the center hole fit snugly on the hub. Also different are the Ford wheels/hubs use 9/16” studs, while our AD Chevy trucks use 5/8” studs.
The first thing to do when searching up more modern wheels for your truck is to know what you need. Knowing your lug pattern, center hole diameter, etc is critical in finding wheels to fit your truck. Here is some info on the factory set up. Given that our trucks have often led hard lives and weren't always maintained according to factory spec, it's always a good idea to check if your wheels and tires are even the correct ones for your truck! There's no telling, sometimes, what might have happened 40 years ago in the middle of a corn field to keep the truck rolling...
'47-'53* "Advance Design" Trucks
7.00 - 20
7.50 - 20
2-Ton(COE & 6400)
* Post 1953: In 1954 the 10-lug center hole diameter increased to 5.25" In mid 1955, GM switched the stock wheel from a multi-piece tubed tire to a single piece tubeless for the '56 model year. The tubed tires (and their wheels) were still offered as an option (and were preferred until technology improved the quality and durability of the early tubeless tires. Stock wheels are 20" (tubed) and 22.5” (tubeless), the bolt pattern is 10-lugs on 7.25" circle. The center hole is 5.25". Studs are 5/8-18. In 1956, Chevy switched to the 6-lug pattern on the 2-ton trucks. We'll be adding info on the later trucks in the future.
Original (Tubed/Bias Ply) size/style
If you plan on staying with your original wheels (assuming they are serviceable and correct for your application), let's go tire shopping! The good news is that 20” tube type tires are easily available to fit the original wheels -- even the 1.5 and 2-ton two or three-piece “locking ring” wheels.
For pickups, check the Links Section for specialty retailers offering new tires to fit your original wheels.
For the Big Bolts, most truck tire centers or Ag stores (like Southern States, Agri-Supply, etc.) can find you modern tubed tires to fit. 7.50X20 is a normal size. 8.25X20 can often be used although with a slight decrease in turning radius because the rear edge of the front tire will rub the springs in a hard turn, most people don’t consider this a problem. Just remember to check what kind of wheels you have -- 2-piece locking rim or 3-piece rims are okay. Center split 2-piece wheels are not. Most big truck or Ag tire facilities will have people knowledgeable and willing to work on your multi-piece rims as long as they are not the center splits. Don't even bother trying one of the chain tire retail outlets.
Upgrading to Modern Wheels and Tires
When upgrading to modern wheels and tires, you will need to find wheels before you can begin tire shopping, so we'll start with the harder effort first.
Please note: Listing every possible replacement wheel to fit your particular application is well beyond the scope of this article.
The point here isn't to present an exhaustive list of what fits and what doesn't, but to educate you as to what to look for, and how to look for it. As long as you know your lug pattern, center hole diameter, etc, and understand the info presented below, you should be well-armed to navigate the myriad possibilities open to you for replacement wheels and tires -- good luck and happy hunting!
Before you do anything else, I highly recommend reading the "general information" section in the Accuride catalog, starting with page 36. It includes chart for matching tire size to rim size/widths, pictures of rim shapes (5 degree tube type different rim constructions, and 15 degree tubeless), how to spot damaged rims (very important for old wheels), recommended nut torque, chart with crossover from tube type to tubeless tires (8.25X20 = 9R22.5), correct dual spacing. All very important info that's well worth reading so you know where to go when questions come up un the future.
So, now that you know what you need to fit (on your existing hubs), you say, "Why don't I get some 22.5" wheels and use modern tubeless tires on my AD truck?" Well, easier said than done. To start with, 8X22.5" tires are very hard to find these days. On the plus side, the 9R22.5 tires are made and easy to get at any truck tire store.
I've looked long and hard and have yet to find any newly manufactured 22.5" wheels made with the small 7.25" bolt pattern we use. In 1956 Chevy used that bolt pattern with 22.5" wheels on the 1.5 ton trucks. As far as I know it was only 1.5-tons, as the 2-tons had 6-lug, stud-centered Budd wheels. Best I can tell these wheels were only installed on Chevy trucks from 1956-1959. That makes the wheels somewhat difficult to find. Although I have seen a few trucks with them, and I have found a set for use on my '48 2-ton.
1-tons & 3/4-tons
3/4-ton & 1-ton w/ singles -- These trucks use the same size stud-piloted wheel (refer to the chart above). The center hole size for single wheels is less critical, as they rely on the studs for location, not the center hole. You can find new single 19.5" tubeless wheels with the 8-lug pattern from Rickson Truck Wheels. Single 19.5” 8 lug wheels (to fit 19.5" tires) can be found used in junk yards -- they may look large, and you could try some different tire sizes smaller than the 8R19.5. Although 8R19.5 tires should just fit without rubbing if you like the look, (and increased road speed). Double check that the countersink angle in the wheels match the lug nuts you will use, as the angle has changed over the years and with different manufacturers/brands of wheels.
1-ton w/duals -- Although the original dual wheels were 18", for modern replacements, use 8-lug dual 19.5" wheels from a 1975-99 “step van” and 8R19.5 tires. They are also available new from Accuride, Rickson Truck Wheels and other sources. I believe Accuride part number 29015 is what you are looking for, but do confirm that they will work before buying. Although I did own some of these 19.5” 8 lug duals at one time, I never tried them on an old Chevy truck.
1.5 & 2-tons
1.5-ton -- See the chart above. Originally, the 1.5-ton trucks used locking ring 20" wheels. Be sure to check the center hole diameter before you buy new wheels, the earlier wheels (prior to 1954) have 4.75" and later ('54 and later) wheels have 5.25" center holes. New 10-lug 19.5" wheels (with a 5.25" center hole) from the larger size 1977-05step van should work look for Accuride part number 27775 or 29667, the second number is a newer and slightly stronger wheel, either should be fine. (See note below). These wheels fit the 8R19.5 tries also, but they are several inches shorter than the original tires. I think they look too small on a 1.5 or 2 ton. If you want aluminum wheels, ALCOA at one time offered the 19.5" aluminum wheels, as part numbers 761001A and 761002A, for use on a Chevy 3500HD or P30 chassis with the 10 lug on 7.25” bolt pattern. Accuride may no longer offer them, but I am reasonably sure they did in the past. I have never seen 20 or 22.5" aluminum wheels with that bolt pattern, though.
2-ton -- See the chart above. Originally, the the 2-tons used the three piece 20" wheels (but same lug pattern and center hole diameter as the 1.5-tons). Be sure to check the center hole diameter before you buy new wheels, the earlier wheels (prior to 1954) have 4.75" and later ('54 and later) wheels have 5.25" center holes. New 10-lug 19.5" wheels (with a 5.25" center hole) from the larger size 1977-05step van should work look for Accuride part number 27775 or 29667, the second number is a newer and slightly stronger wheel, either should be fine. (See note below). These wheels fit the 8R19.5 tries also, but they are several inches shorter than the original tires. I think they look too small on a 1.5 or 2 ton. If you want aluminum wheels, ALCOA at one time offered the 19.5" aluminum wheels, as part numbers 761001A and 761002A, for use on a Chevy 3500HD or P30 chassis with the 10 lug on 7.25” bolt pattern. Accuride may no longer offer them, but I am reasonably sure they did in the past. I have never seen 20 or 22.5" aluminum wheels with that bolt pattern, though.
Both -- In my opinion, most desirable option for either a 1.5 or a 2-ton is a set of 10-lug 22.5" wheelsfrom a '56-'59 Chevy 1.5 ton. Same deal with the 5.25" center hole. They are not real easy to find, although prices are generally fair if you do find some. Many tire choices are available, and 9R22.5 is probably a good one, comparable to 8.25X20.
Note on the 10-lug wheels with 7.25” bolt circle -- The one problem you may have with the new wheels is the wrong center hole size. To start with you need to know what size center hole your original wheels have, actually measure it, or get an idea from the list of years and bolt patterns below. All the new style tubeless wheels have a large 5.25” center hole (except for the larger ford 5.46 center hole wheels). The problem comes when you want to use these new wheels on an older (generally pre 1954) truck, as there is a ½” difference in hole size. Because these wheels are hub-piloted and it is very important that the center hole fit snugly on the hub as designed.
To allow use of new wheels on the older trucks, a set of simple spacers may be needed. For the front these spacers/bushings would be just less than the thickness of the wheel measured at the stud holes, a shrink or press fit on the hub (nominal 4.75”), and a slip fit in the wheel (nominal 5.25”). If you used the original front clamp plate (that has only 5 lug holes and covers the other 5) the adapter bushing could be a slip fit on the hub, as this cover would keep it from falling out. The rear spacers/bushings would be similar to the front, but twice the thickness to allow dual wheels. If it was not a press fit you could again use the clamp plate like on the front, but with 10 stud holes (these clamp plates are stock). Some Loctite and frequent inspections may also work to retain the bushings.
The clamp plates' purpose is to add strength at the center of the wheel. The wheels are designed to use the clamp plates. I have used big washer face lug nuts without the clamp plates, but am switching back to using the clamp plates now that I know better.
Before you purchase any wheels -- I highly recommend test fitting any wheels you are considering for your 1.5 or 2-ton truck. These trucks are quite likely to have conflicts with 19.5" wheels -- brake drum interference can be a problem depending on brake size.
Now that you've found wheels to fit (hopefully!), let's consider your new rubber.
Modern Tubeless tires
The first thing to remember is that the diameter of the tire must match the diameter of the wheel. EXACTLY. i.e., 19.5-inch tires MUST be used on 19.5 inch wheels. With that in mind, new tubeless and radial tires to fit our 1.5 and 2-ton AD trucks are available. The easiest wheels to find seem to be the 19.5" tubeless 10 lug wheels, as found on the Chevy P30 chassis, 3500HD and other trucks in the 80’s until about 2005. Again, 19.5” tires can not be used on 20” wheels; new or used 19.5” wheels must be used. The tallest tire available (without being really wide) in 19.5" is an 8R19.5, and they are about 32" or 33" tall. I think they are intended to be a replacement for 7.50X17, although I am not 100% sure on that. If you replace your stock 7.50X20 tires with the readily available 8R19.5 tires (and new wheels) they will have a smaller outside diameter. Some people don't mind, I personally think they look much too small on a 1.5 or 2 ton truck. With smaller tires you will also lose road speed, not good for our already slow trucks. On the plus side, smaller tires give increased braking performance.
The 22.5" tires are available with an outside diameter "OD" similar to the original 20" tires used on our trucks. Therefore, upgrading from 20" to 22.5" wheels and tires (if possible) is to be preferred over the smaller 19.5" wheel/tire swap. For example, 8X22.5 is the tubeless direct replacement (approximate same OD, and approximate same tread width) for 7.50X20. The replacements for 8.25X20 tires are 9R22.5. This info is on page 45 on the Accuride catalog. There are lower profile 22.5" tires that you may use. They will be labeled as 245/75R22.5, or some such mess of numbers. I don't know the details and sizes as to what replaces what for those. To run readily available 9R22.5 tires on your AD 1.5 or 2 ton, you need a set of hard to find 22.5 wheels. They are not available new (see wheel section above for details).
A Note on Metric Tire Sizing
Metric tire sizing works like this -- as an example lets use the tire size 245/75R22.5. The first number, 245, is the width of the tire (when mounted on a specified wheel width) measured at the widest point, usually from sidewall to sidewall, this is the "Section Width" (cross section) in millimeters. 75 is the tire's profile or aspect ratio, in this case sidewall height (from rim to tread) is 75% of the tires section width, or about 184mm. Next is "R" for "Radial". And finally 22.5 is the rim diameter in inches measured at the bead seat. The mm measurements can then be converted to inches by dividing the number of millimeters by 25.4 (the number of millimeters in an inch).
Remember When scouting for more modern wheels to fit your truck, the best thing you can have with you is an accurate measurement of your wheel diameter, bolt pattern and center hole diameter. And whether your truck needs a stud-piloted or hub-piloted wheel. New/different/replacement wheels should be test fit before buying, as brake drum interference can be a problem, particularly with 19.5" wheels on some AD big bolts. You will see a LOT of wheels in junkyards and swap meets -- many of them will look like what you need, but WON'T BE! Know what you need! Measure twice and buy once!
We live in the land of the free, because of the brave who left home on our behalf.