Gear Change
- Thread starter B Atkins
- Start date
What you have sir is a very nice truck! It is so nice to see something in good shape and apparently original.
The l 120's rear axle was an IH built unit. Axle code is 1402 with a model number r 1070 (going on literature of the day); drop out gear set.
The ratios available were: 4.1:1; 4.77:1; and 5.13:1. There might be a tag left on it showing the ratio. Or you can count the drive shaft turns it takes to equal 1 revolution of a wheel.
Your only option to change ratios is find the same model axle with a different gear set.
You might try contacting a gear man up here in oregon, dave wimsett "dave the gear man." he specializes in drivetrains, and worked for IH years ago. He seemed pretty well connected with supply chains when I met some years back. His number is 541-912-1698.
The l 120's rear axle was an IH built unit. Axle code is 1402 with a model number r 1070 (going on literature of the day); drop out gear set.
The ratios available were: 4.1:1; 4.77:1; and 5.13:1. There might be a tag left on it showing the ratio. Or you can count the drive shaft turns it takes to equal 1 revolution of a wheel.
Your only option to change ratios is find the same model axle with a different gear set.
You might try contacting a gear man up here in oregon, dave wimsett "dave the gear man." he specializes in drivetrains, and worked for IH years ago. He seemed pretty well connected with supply chains when I met some years back. His number is 541-912-1698.
Last edited:
Scoutboy74
Moderator
That is sharp and clean. Not many gearing options according to my friend greg. I suppose going from a 5.13 to a 4.1 would make for a decent reduction in engine speed. Not that much of a gap between 4.77 and 5.13. It might be tough to justify the work in that case.