Hello all.
Neat truck! Just making sure . . . this isn't the truck that belongs to Boomer/Todd is it?
Hopefully, I can help with some specific info.
Check out my FaceBook page (International Harvester 140/160 4x4 Trucks) or website (
https://ih1404x4.weebly.com/) and let me know if I can help in any way. I'm rarely on the OldIhc site. Facebook is the best way to reach me.
When IH wanted to make the R-140 4x4, they started with the 150 frame added a heavier steering box (I think from a 160 or 170).
The front axle is an Eaton designed, IH built 5,000lb rated axle. It's most commonly called a FA50 axle, but I've also seen it listed as F480 in IH literature and F5000/FD5000 elsewhere. It uses a Bendix-Weiss 5 ball design. Some folks call it a "ball & claw". The R-140 and S-140 were typically identical, but when they went to the A/B body style, the axles got wider and they changed the transfer case. The R/S 140/160 used the Timken (Rockwell) T-32 transfer case. The A/B 140/160 4x4's used the Rockwell T-223 transfer case.
160 4x4's used the same front axle and transfer case as the 140 of the same body style, but the frames, rear axles, etc were a little heavier. You could also get a 7,500lb axle in the B-160 4x4's, but I've only seen a few of those over the years. (EDIT: There were also a few S-160 4x4's that were built with the 7,500lb front axle. IH would build pretty much whatever the customer wanted.)
Most 140 4x4's had 11,000GVW, but some were uprated as a 142 or 144 and had 13,000GVW. Most 160 4x4's had 15,000GVW. Interestingly, many manufacturers simply added the front and rear axle capacity to get the GVW rating of the truck. In my opinion, IH underrated (overbuilt) their trucks. For example, the R-140 4x4's had a 10,000lb RA20 rear axle and a 5,000lb front axle, but a GVW of 11,000-13,000lb.
Another interesting item about the 140 4x4's is that the chunk (carrier/differential/ring & pinion) in the FA50 front axle and the RA20 rear axle will interchange. (You just have to flip the oil scoop. Some RA20's had a Detroit No Spin, which wouldn't work well in a front axle!) Additionally, the same chunk was used in the RA15 rear axle used in so many 130/1300 series IH trucks. This would also allow someone to change the 6.16 gears in these trucks to the 5.57 or 4.88 gears used in the RA15 axles. I believe there was also a ratio in RA15 in the low-4's, but I can't remember the ratio. (EDIT - A 4.30 ratio was also available in the RA15 rear axles.)
The 140 4x4, according to IH paperwork, should weigh around 5,200-5,500lbs without a bed. How much do ya think that 9.5' bed weighs? 300lb? If it has fishplates on the frame, that would add a few pounds also.
The front sheet metal is the same as the 150-180 trucks, with one possible exception that I'm aware of, which is that the 140's with the 17" wheels/tires (and probably the 150's with the 17" wheels/tires) had a smaller wheel opening in the fender. The sheet metal will interchange between the 140-180 trucks even with the different wheel opening. It just might look odd to have the fenders with the smaller wheel opening on a truck with 20" or larger wheels/tires.
I have lots more info on these trucks, so let me know if you have more questions.
Can you post a pic of the data plate or serial number? If so, I can give a ballpark of when it was manufactured. Take care. Good luck!