I am going to get a locker for my rear axle, but I didn't know what spline count it had. So I pulled it out today and I only counted 16 total splines. To my knowledge I thought there should have been 31 or 35 splines. My truck is a 1973 F250 4x4 high boy. The rear axle is a Dana 60 with 4.10 gears. Has anybody heard of so few splines on a dana 60? I would appreciate any input.
Thanks Derek

 

Don't sweat it, that is very common on all the old d60 axles. I thought the '72s got the last of the 16 splines but I must be wrong. The 35 spline is the strongest, but in terms of thickness and strength the 16 spline is as stout as the 31, so need to worry. Its a strong axle.

 

I have that exact same truck and had the same axle count too, I was told that it was common and more than strong enough. As for a locker, you might have some kind of limited slip now, mine does. Some of the limited slips require a tap on the brakes to engage both wheels as mine does.