Bruce A. Frank
Member
This subject keeps popping up in my thoughts. I read somewhere that the ra-10 is based on an eaton design but built by ihc to their ideas. Wondering if anyone knows of any interchangeability with parts of an eaton axle?
Decades ago, as I have related on this site, I had my first s120 which had a crack in the differential area on the front d44. I found a pickup in a salvage yard in slc that had suffered a fire shortly after restoration. It was a later model pickup than was my '56 s120 Travelall. The front d44 was the same but with a variation in spring perches. I made some mods on the spring mounts on my frame to make the match and it went well.
But I had a problem. The highest speed axle ratios listed for the '56 s120 was 4.11. The "new" front I'd found was a 3.73. Pulled the ra-10 diff on my s120 to check the gears(no tag or stamp that I could find) and found it to also be 3.73. How could that be?
The rear axle under the pickup appeared to be a duplicate of my ra 10 and the tag on the bolt in the diff housing said 3.73. Great, I was set. My "new" front axle worked and I put 200,000+ miles on the vehicle.
Now the puzzle. The s120 I had came from the u of utah geophysics dept and had only 80,000 on it when I bought it. It had been student abused. Since the 3.73 gear set was not a listed part I have to assume that the u at some time had changed the third member to one from a later model ihc vehicle. My question is, is there data out there on ra 10 used in later models with the 3.73 gear set or was the third member exchangeable with the "similar" eaton? Or, another ihc model axle that shared the same removable third member as the ra-10?
My desire is to change my ratios on my current s120 Travelall to 3.73. Any help would be appreciated. The front d44 should be relatively easy. That ra 10 is the problem. And, no I do not remember the model of the pickup, though I vaguely place it as an early '60s model ('64-'65?).
Decades ago, as I have related on this site, I had my first s120 which had a crack in the differential area on the front d44. I found a pickup in a salvage yard in slc that had suffered a fire shortly after restoration. It was a later model pickup than was my '56 s120 Travelall. The front d44 was the same but with a variation in spring perches. I made some mods on the spring mounts on my frame to make the match and it went well.
But I had a problem. The highest speed axle ratios listed for the '56 s120 was 4.11. The "new" front I'd found was a 3.73. Pulled the ra-10 diff on my s120 to check the gears(no tag or stamp that I could find) and found it to also be 3.73. How could that be?
The rear axle under the pickup appeared to be a duplicate of my ra 10 and the tag on the bolt in the diff housing said 3.73. Great, I was set. My "new" front axle worked and I put 200,000+ miles on the vehicle.
Now the puzzle. The s120 I had came from the u of utah geophysics dept and had only 80,000 on it when I bought it. It had been student abused. Since the 3.73 gear set was not a listed part I have to assume that the u at some time had changed the third member to one from a later model ihc vehicle. My question is, is there data out there on ra 10 used in later models with the 3.73 gear set or was the third member exchangeable with the "similar" eaton? Or, another ihc model axle that shared the same removable third member as the ra-10?
My desire is to change my ratios on my current s120 Travelall to 3.73. Any help would be appreciated. The front d44 should be relatively easy. That ra 10 is the problem. And, no I do not remember the model of the pickup, though I vaguely place it as an early '60s model ('64-'65?).