I am seeing replacement wheels for trucks sized 31, 33, 36 (Inter Mountain, Kadee, Etc) and 40 (Precision Scale and NW Short Line) How do I know what size wheel sets to purchase for my truck over-haul project? 36 seems to be the most common. I am thinking maybe the truck type dicatates the size of the wheels-or is it something else? Thanks for all of the advice.
Weight carrying capacity is one thing that dictates wheel size. The 33 inch wheels are the most common on older and smaller rolling stock, with 36 inch being used mostly on modern covered hoppers. The 40 inch wheels would most likely be for diesel locomotive replacments. Some well cars for containers use 31 inch wheels on the ends and 33s for the intermediate trucks.
TOFC flats and auto racks also often have the smaller diameter wheels in many cases. You have to check each appluication, as they vary.
Passenger cars typically ran 36" wheels. Be aware with many older plastic trucks, smaller wheels were used for clearance purposes. Old AHM/IHC cars may need brake shoes trimmed, etc to clear 36" wheels. Some test fitting is in order in any case before you make a big investment in wheels for any such conversion.
Basically, if you model before 1980 or so (very roughly, as there are exceptions ) 33s go on everything freight except covered hoppers (taller and became widespread after the bigger capacity - 286000 lbs? was allowed) and speciality flat cars (lower), while passenger cars get 36". After that, things get considerably more mixed up.
When buying replacement wheelsets, you should also check the overall width over the ends of the axle. This can vary among manufacturers and result in poorly running trucks if not well-fitted.
Mike Lehman
Urbana, IL
A general rule of thumb:
Most cars including older covered hoppers up to 77 Ton capacity used 33" Wheels.
100 Ton Capacity Cars, all newere covered hoppers, some of the 60' and 86' Boxcars depending on the capacity of the car used 36" Wheels.
125 Ton Capacity, like some of the more modern cars, but older cars like the Flexiflow Covered Hopper, the NYC/P&LE Hot Coil Cars and the end units on the large container cars (the intermediate units used 33" Wheels.) used 38" Wheels.
28" Wheels were used in intermodal / autorack service to get a lower profile car as weight of loaded trailers and autos did not max out the capacities of these cars.
40" Wheels as mentioned in a previous post were used on most engines although the EMD E series used 36" Wheels and some Baldwin Engines used 42" wheels.
31" wheels were the size on all AHM cars as the flanges on those cars originally had the NEM specifications (a very deep flange) and when AHM/Rivarossi changed to the RP25 flange they left the wheel diameter at 31" and this is not a prototype wheel size.
Also, the sideframe could be the same on all the various wheel sizes but the journal size, length and spring package would determine the capacity that the car could carry.
Rick J
Rule 1: This is my railroad.
Rule 2: I make the rules.
Rule 3: Illuminating discussion of prototype history, equipment and operating practices is always welcome, but in the event of visitor-perceived anacronisms, detail descrepancies or operating errors, consult RULE 1!
Thank you gentlemen. This will certainly help me decide what I will buy new trucks for and what units I will try to just upgrade with new wheel sets.
I haven't seen 31-inch wheel sets offered by Intermountain, Proto 2000, Kadee and other makers. They must be fairly rare?
FYI, you can get a set from Reboxx which is a sample set with various sized axles lengths to test if it matters. I've found more often than not, the worst case is axles can be a little on the sloppy side but work fine - like the bulk pack of 33" Intermountain wheels I have installed.
Rio Grande. The Action Road - Focus 1977-1983
IHC inherited the undersize 31" size from Rivarossi and AHM but they eliminated the NEM flanges but kept the diameter. Only in code 110 though.
Hello all,
Another thing to consider (especially with NWSL) is axle length.
Many manufacturers offer different axle lengths. I discovered this at a closeout sale where only wheel sets left had narrower or wider axles than the "stock" size.
To paraphrase: "Measure twice, purchase once."
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
I was just about to post this exact question as there are some pieces of rolling stock that I would like to upgrade and was confused on which cars needed 33" and what needed 36"
some hoppers I have say the weigh 162000lbs so they would need a 36" wheel correct ?
The controling factor is the trucks that you are mounting them in. What will they take, what can you get away with before yo bind floors or other elements.
You must be ready to buy severral sets of wheelsets to keep on hand and use where you need them. Do hnot be afraid to spand the money while the car is still in the shop, it costs a lot of money to bring cars to the shop. You want them to be correct when they go back out again!
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS