Dana 44 Pinion Spline

I am collecting parts for my CJ6 project with waggy axles. I have several older early cj dana 44 axles with 5.38 gears. I was going to swap the gears over to the waggy axles. I am wanting to run 23 spline flanges instead of yokes for the driveshafts. I looked in the parts book last night and noticed some dana 44 in the early cjs had 10 spline and some had 23 spline. The years overlap by quite a bit. Is it just luck of the draw which one you have. Any certain models have a certain type. Not that it matters I'm kinda curious if anyone knows why they would use two different types in the same jeep in the same model year. I am currently away from these axles so can't go out and check right quick.

 

Hate to say it but you're going to have to look to see what you have. Overlap most likely to use up existing stock of gears and new manufacture of commonly used ratios. Most older Jeeps used the coarse 10 spline but it depends on what year you have and what ratio.
The 23 spline is stronger so I'm sure that's part of the reason for the switch as well as to come in line with what other manufacturers were using (cost).