A friend of mine has a 36 1.5 ton dump truck that he hopes to make a parade unit for his HVAC company. His grandfather and dad started out delivering coal way back, and this is a great unit. However, the tires need to be replaced. The backs are 7.00-20's and the fronts are 6.50-20's. Those are not an easy find anymore. 7.50-20's are easier to find, and 8.25-20's are even easier. What I don't know is what will work with those rims. Any thoughts? I know our 1952 1/2 ton would handle several sizes, but I don't know how adaptable the 20 inch rims are. And given they are 2 piece, I'm letting a pro do the work. Also, I've seen some similar rims on facebook or craigslist, but don't know if the rims would fit the 36. Anyone know what year rims might interchange?
Thank you!
Jake53
Last edited by Peggy M; 08/03/20247:41 PM. Reason: added more info to the title
There were at least a couple of different wheels that could be correct for a 1936 1-1/2 ton Chevy. The wheels differed to match the tires that were on the truck. The standard wheel was suitable for a 6.00 or 6.50 X 20 tire. The '36 and earlier wheels are recognizable for their very triangular hand holes. According to my 1929-1949 Master Parts Catalog, these are "one year only" wheels. The full floating rear axle appeared in 1936 for the first time on a Chevy truck. This required a larger pilot hole in the center. The '35 and earlier wheel had a 4-1/4" hole. This was enlarged to 4-3/4" in '36 and remained at this size for many years. Wheels from AD, and possibly later trucks will fit your friends '36 and it is not uncommon to find that this has been done. The additional width and dish can be an issue, mostly on the left front where the tire can rub the drag link when turning to the left. My 1936 RD 1-1/2 ton Chevy had later wheels on the outboard duals, when I got it. They were the super heavy, 2 ton type which weigh 100 lbs. or more. The truck was wearing 7.00 X 20 tires and the wheels with more offset may have been required to prevent the tires from contacting one another at the bottom bulge when the truck was loaded. This is speculation on my part. I was lucky to find a pair of NOS wheels which matched my four originals. After much searching for a 7th wheel, I finally took a '35 wheel to a machine shop and had the pilot bored out so I could have a spare. The '35 and '36 wheels were identical except for the pilot hole. I put 6.50 X 20 tires on the truck because I already had a set of 6 and because Chevy info called for them. I am happy with the look. My speedometer reads about 5 mph slow so the 7.00 tires would have corrected some of this and a simple spacer would have solved the possible issue of tires coming in contact with each other at the bulge. I am fortunate that my truck has the faster of the two gear sets that were available for 1936. I believe they are 5.43. One more thing. These wheel use a continuous ring that requires much care and caution when mounting tires. I did this work myself. It is possible to distort the ring when removing it. This increases the danger factor. I am 75 years old and grew up on a farm where my Dad did most of his own tire work. I learned to respect/fear these wheels and always put chains around them in a couple of places when airing them up. I also put air in from the back side to the ring is facing away fro me. Start with a little air and check the ring for centering before adding more air. The wheels and rings should be thoroughly inspected before they are used. I think you can see my truck by clicking the link at the bottom of this post. I hope all this rambling is helpful. Feel free to contact me if you think I can help with anything else.
Thank you both! I had looked at the Coker option but was dealing with some sticker shock.
I saw a set online that someone had for sale, in 8.25-20 from a Chevy, but the center hole was almost 6 inches, and of course the bolt spread would then be bigger too. Seemed like a nice option, but not meant to be.
Do you think I'd have any issues if I went with the 7.50X20's? It would save a ton of money, as I can get those for half as much, and with free shipping. I'm really tempted, but not sure.
Do you know the rim width of your wheels? The first mention of a 7.50 X 20 tire, in the parts catalog, calls for a 6 inch wide rim with 5-3/8 " offset and is applicable to 1946 and later models. There is a 20 X 6 wheel shown for 1936 but says for single rear wheels only. It has only 3-1/4" offset and is for a 700 X 20 tire. You can make a spacer to go between your rear duals to gain some room but the larger tire will rub your drag link on the left front when you turn left. This could also be the case if you use later wheels to get the required rim width and offset for the rear. The same offset that solves the problem at the rear, creates a problem at the front.
Let's start by deciding what wheels you have now. Here is a picture of my 1936 truck before I blasted and powder coated my rear wheels. Note the very triangular hand holes in the wheels. I believe '36 was the last year for this design. Later wheels had holes that were more "D" shaped. At the time of this picture, my truck was wearing 6.50 X 20 tires on the front and 7.00 X 20s on the rear. I hope this helps. Mike
