Tech Tips on Tires and Rims

Tire Identification -- How Old Are They?

Jim asked on the CJ-3B Bulletin Board how to tell if his tires are originals (as the previous owner claimed.)

Well, the type of tires originally installed would depend on what year of Jeep we're talking about. In the 1950s, tire size was specified as 6.00x16, 4 ply (7.00x15 optional, also 7.00x16 on military M606.) Most CJ-3Bs came with military-style non-directional tread tires (see Tires For Your CJ-3B on CJ3B.info). We don't currently know exactly when these were replaced as standard equipment by a newer tread design; possibly when 15" wheels became standard in the early 1960s.

Toledo 1959This factory photo, believed to have been taken around 1959, shows both NDT tires (right) which were perhaps only being used on military orders at that point, and at least a couple of other types of tires.

Bill Oakes said on the Bulletin Board that Goodyear Suburbanites (400K JPEG) are the originals on his '62 CJ-5. The tires on the left in the photo look similar, although not identical, to the original Suburbanites that were still on a 1963 CJ-3B in 2002.

Keith Buckley provided this information: "I don't know when the DOT (Department of Transportation) started tire serial numbers, but most tires in the last 50 years that I have seen, have a DOT serial number on them.

"The first 2 digits indicate tire manufacturer and which plant location they are made in, the next 2 indicate the tire size, the next 4 are option symbols that can be used by the tire manufacturer, and the last 3 indicate the week and year the tire was produced (example: 032 = the 3rd week of 1952,62,72,82,or 92). on July 2, 2000 this was changed such that the last 4 digits indicate week and year (0302 = 3rd week of 2002).

"This means if the particular tire line you are interested in was made for over 10 years you had no idea of what decade they were from. You can usually figure it out from the dealer advertising, or old copies of the Bennet Garfield Tread Design Guide. I have them from 1966 up, but only every 4th year or so. Their web page is at www.tireguides.com and maybe they have info on past years?"

(Note: There is lots of useful tire information on the Tire Guides site.)


Original wheelNeil asked: "I was just wondering what bolt pattern the Willys rims are the same as -- Ford, Dodge, or GM? I would like to put just plain steel 15-inch by 7 or 8-inch rims on my Jeep and would like to go to a wrecking yard to get these rims but don't know what to tell him for size."

Louie Larson responded: "Your bolt pattern is 5 on 5-1/2. The following have them: CJ-5, CJ-7 all years, Jeep full size trucks and wagons up to 1972. C-101 Jeepster Comanando '67 to '74, IH Scout all years. Ford truck wheels have to have the center machined to fit over your front hub. All the aftermarket wheels with this 5 on 5-1/2 bolt pattern have the large center hole. I run Americam mag alum 8" wide wheels with 235/75R15 with great success."

Bobby added: "The Lada Kosak and Niva Jeep use the same pattern. I think Ford wheels from a 4X4 should have a large enough center hole, unless Ford's locking hubs were smaller than the Jeep's."

Rus Curtis commented on CWML: "There were solid rims on early 2A's and slotted Kelsey Hayes or Motowheels rims from then on. I've been looking hard at the 15" wheels specifically, for my '54 3B. The original ones I have (photo at right) are riveted. I've discovered that there are also welded wheels as well. Do the welded wheels pre-date the riveted type or visa versa? Since mine are riveted I assume that riveted wheels were the available wheel in 1954. Yet after checking, I've discovered what appears to be another '54 3B with welded rims. Were they manufactured side-by-side?"

Left/Right Lug Nuts

LMany a first-time Willys owner has been puzzled by the wheel lug nuts. I stripped one of mine before I finally figured it out.

Charlie C: "I'm about to remove the wheels on my '54. The studs are marked with "R" on the passenger side and "L" on the drivers' side. My question is: does "L" mean loosen lug nuts by turning to the left or tighten by turning left? In other words, which side is not standard?"

The first response: "L = left hand threads, loosen turning clockwise, and the other side the opposite (normal) direction."

RBob S. added: "Easy way to remember: no matter which side you are on, turn toward the back to loosen."

A word of caution: sometimes the "L" and "R" are packed with grime and you don't notice them. Make sure the "L" hubs are on the left and the "R" hubs on the right. Apparently at that time there was a theory that normal lug nuts on the left side would work loose and cause the wheel to take leave of the vehicle. It has since been disproven.

Worn Wheel Lug Holes

Tom asked on the Bulletin Board: "The wheels on my 3B have had some abuse over the years but are generally true. The problem is I have about one or two bolt holes on each wheel that have been "wollered" out. Is there any fix for this other than replacing the entire wheel? Oversize lug nut? Some type of washer?

H. Wooldridge: "I assume the holes are worn so much that the lug nut bottoms out and doesn't contact the wheel. I would think about running a weld bead inside the holes and redrilling. You could also recut the bevel on the lug nut to a more shallow angle but then you'd have a few that were different from all the rest."

Ed Wilson: "A flat washer and a standard NF nut (1/2-24) should work fine. I don't know about the availability of left hand thread if you have the left hand threaded lug bolts on the left side. And of course the appearance might not be what you want.

"If you have a machine shop that will take small jobs, they can weld up and reform the holes. This is not a difficult job and would look original. Considering the price of the repro wheels, I would look into this option if it were mine."

Tom wrote back: "That's what I thought, since I don't have the needed equipment for the re-drill and bevel. It can be done but it appears to be almost the cost of a wheel by the time you get it done. So I might just run some washers until I decide on new wheels. I have been running the washer with the original lug nut. It kind of flares out the washer a little but so far it stays on."

But Steve replied: "You might be surprised. Check some small body shops to find one that would run a bead around the hole in question with their MIG welder. 10 minutes labor, tops. You can then use a handheld grinder, or a grinding wheel on a drill to level off the surface. From there, use a drill bit to clean out the hole, and a larger drill bit or a countersink bit to recreate the bevel. A quick clean-up with a wire brush and a couple of shots from a spray can and you are back in business!"

Tire Size

Someone on the CJ-3B Bulletin Board asked: "Does anyone know if 235/85 tires will fit on my stock 16-inch rims? If not, what is the widest tire these rims will take? I want to get some tall, narrow tires but hate the thought of buying aftermarket rims."

John responded: "I am sure there are people on this site that have mounted 7.50x16 bias ply tires on a 4.5" wide OE rim. I am pretty sure of that since several have contacted me and asked why they now have an undriveable Jeep due to front end shimmy, but that's a whole other story. I have not done it, but was also told by the Goodyear guy that I could. I had Michelin 7.50x16's on my trash trailer and Michelin 235/85's on the truck that pulls it and the 235's are quite a bit wider. A good compromise might be to find stock Willys pickup wheels. They look just like the 4.5" wide 16's that are on the CJ's, but are an inch wider-5.5" wide or something. The Goodyear guy would probably tell you a 6" wide rim was the narrowest for the 235/85's, but I'll bet you could mount it on a 5.5" wide rim.

Another reader said: "Goodyear says 235's should be mounted on 6-7" wheels. I run 215-75-16 Goodyear AT/S blackwalls on one of my 2A's and my FC-170, both with 4.5" wheels. Goodyear says 5-6" for 215's. Excellent tires and they have the tall look I believe you are after."

Bill Oakes recommended Buckshot bias ply and radial tires.

11-15Here is the formula for the modern tire size system: The first number is the width of the tire in millimeters. The second number is the aspect ratio, that is the distance from the rim to the tread as a percentage of the width. The last number is, of course, the size of the rim.

Conversion: The metric tire width is taken at the widest point of the tire. I don't know about the old way. My 7.00-15s seem to be about 8" at the widest point, but my 11-15's (photo at left) look like they're about 11 inches. If my 7-inchers are like all the other ones, we should be looking at 205s. For a 28" diameter tire, it works out to be about a 205/75R15.

Tires -- Tubes or Tubeless?

Jerry O. asked: "I'm about to buy some new NDT tires for my CJ. What are the benefits (if any) of 6-ply over 4-ply? For my 1945 CJ I'm looking at 6.00x16's, which I believe is correct for that year. The tires on now have tubes and are cracking a little, but they've held air for two years so far. Should I go for new tubes at the same time, and is there anything else I should be on the lookout for?"

Wes Knettle: "The 6.00-16 and the 7.00-15 were the standard tire choices. I think the advertising literature you have seen quoting 4 ply and 6 ply actually says 4 ply rated and 6 ply rated. This means that the 4 ply rated tire has only 2 plies and the 6 ply rated tire has only 4 plies. My personal preference on the highway is at least 4 actual plies in the tire. For show and low speed driving the 2 ply will work. If you're not in a hurry then pull your tubes and inspect them before you decide to buy new ones. There should also be a rubber flap or band like unit that fits snugly around the center of the wheel to protect the inner tube from chafing on the wheel. You should also make sure the hidden area of the wheel that is exposed after tire removal is clean and rust free."

Chuck: "Then the question becomes, can you run the wheels tubeless? This question came up before on a tire-related subject, and I don't think the lady was ever given a concrete answer. When I went to the tire shop to get some Denmans for my M38A1, I came back to find mounted tires on wheels. No tubes, or flaps. I was a bit concerned but they have held up so far. Jerry, I would consider non-NDT's if you will be doing any serious highway driving."

Bruce W: "I believe there were changes made to the wheel rim when tubeless tires became common. This could include the shape and angle of the rim where the tire bead contacts it to insure a good seal, and later on, a safety ring to keep the tire on the rim when it goes low or flat. Also, wheels with the centers riveted into the rim may leak at the rivets. I have seen, and even installed myself, a lot of tubeless tires on older, tube-type wheels with no apparent problems though. You're probably not likely to find anyone in a modern tire shop that can tell you the difference."

TubeTom had a number of good suggestions: "The tube vs. tubeless question has a two part answer. If you want to run tubeless tires you need to have a wheel (steel in our case) that has no pin holes or cracks in it, and tires that are made to be mounted tubeless. Most modern one-piece automotive rims, whether riveted or welded design, will hold air as long as the valve stem has a tight seal, and there are no rust holes (especially around the rivets). The tires on the other hand need to be constructed with the inside of the tire carcass sealed, so that air will not diffuse out through the rubber. The Ag industry has traditionally used tube-type tires, and tires marked as such do not perform well mounted tubeless. Tubeless advantages: less parts so they are easier to mount,less weight, less problem in balancing, if they pick up a nail, they lose air slowly. Tube-type advantage: if you have an old tire that has a heavily checked carcass you can still get it to hold air (low speed is advisable). Tube-type disadvantages: many parts make it tricky to mount, may be difficult to balance, and if you pick up a nail, they go flat immediately. When we converted our schoolbus fleet to tubeless tires back in 1986 we went about 4.7 million miles before we had our first flat tire, and it went flat here in the yard, not on the road.

"If you do want to mount tires with tubes, try these tricks:

  1. Make sure the rim is smooth with no nicks or gouges.
  2. Try to use a "flap" (band of rubber) to prevent the rim from chafing tube. Sometimes you can make a flap for a automobile rim from a piece of an old farm or contruction tire tube.
  3. Use rubber lube when slipping the tire bead onto the rim.
  4. Use talcum powder on the entire tube so that it won't stick to the inside of the tire when the tire flexes.
  5. Use tire irons or spoons to mount and dimount tires. Not screwdrivers.
  6. Start at the valve stem and work away from it. That way you will be less likely to catch it with a tire mounting tool.
  7. Try not to pinch the tube between the rim and the tire iron.
  8. Inflate and deflate the tire at least two times before you consider the job finished. That way the tube will seat the tire bead, and then have a chance to lay back down flat and wrinkle free, inside the tire, before you inflate it for the final time.
  9. NEVER EVER EVER EVER inflate a multi piece rim (also called split rims) without using an inflation cage. If something goes wrong during inflation, the potential for severe injury or death is great.
  10. Have fun doing it. There is nothing like the feeling you get when you have 'wrestled' a tire onto a rim, without the use of some fancy machine down at the tire shop!"

Thanks to everybody for their comments, and to Andy Stock for assembling them. Factory tire photo from the Images in Time collection at the Toledo Lucas County Public Library. -- Derek Redmond

Also on CJ3B.info, see lots more advice on choosing Tires For Your CJ-3B.

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Last updated 1 January 2005 by Derek Redmond redmond@cj3b.info
All content not credited and previously copyright, is copyright Derek Redmond