I have a "pinion" in a "CAT" box. Pinion is stamped 2B8246. I can't find this # anywhere but in tractorparts.com cat listings that just say "pinion". It is straight tooth, not helical. I'd guess 20" long, tapered with threads at small end. I sealed it back in orig. box but forgot to count the large straight teeth. I would guess ten or twelve. I hate to tear open the box again as it is old and weak. Anybody out there know what this pinion would fit?

That is all my paper NPR says too. It does say it weighs 27 pounds.
Ken

In 1958 it cost $65.98 new from Cat. That was still no help on what it fit.

NPR says fits a whole lot of wide gauge groups. The first group listed was for Forty, Diesel 40, RD6 and R5. This is a final drive pinion. The early Forty and Diesel 40 used keyed tapered end, then the splined design was used.