Easy Way To Tell 10 Or 19 Spline ?

What would be the best way for a quick check to identify between an early 10 spline or 19 spline rear axle.
If the stock gears were still attached, what year was the change made?

 

The change to 19 involute splines occurred in conjunction with optional D44 Powr Lok differential units.
Very late in the 1956 model year.

 

Ok that is some help. I picked up a rebuilt offset cj5 rear 44 with 4.10 gears and a disc brake narrow 30 with matching gears. This is one with the little weep hole on the left side. We took the cover off for a quick peek, just don't remember checking for the year. Thinking it may not be worth installing behind the 225 and if I sell it might be best if I knew it was a 19 spline.

 

Yeah, 19 involute spline is certainly larger diameter and stronger than a ten milled spline shaft.
Since the gears were changed out there is no reasonable way to determine exact year of manufacture.
The only differences between a 10 spline and 19 assembly would be the shafts themselves and the differential side gears.
Everything else remains identical.
The housings and differential cases also change whenever you go to 30 rolled spline shafts.

 

If nobody is going to say it, I have to-the difference between 10 spline and 19 spline is----9 splines. ahhahahahahaha

 

I wonder if one could decipher the clock or numbers? Also it appears a spacer was needed when changing out to 11 inch brakes or perhaps was used on the older 44's?

 

Chances are pretty good it's 19. Is there a powerlok in it? Can you just pull the cover and look? If it's open diff, you can probably see the ends of the shafts well enough to tell what the spline count is. If it has a powerlok, then you'll have to pull a shaft to know for sure most likely.

 

Can't see the whole housing but best I can tell........
That particular D-44 housing sure looks to be the late 1960's version. (1965-1970)
It's different than the earlier castings with a bigger reinforcement webbing along the side.

 

Ok so if I was to convert to a full floater even though it was a 19 spline it should be strong enough for a low geared v6 engine?

 

If you're going to go the cost and effort of a full float conversion, why not go with 30 spline axle shafts and a selectable locker or similar?

 

It is more like I found another 19 spline axle that is a full floater already with a Detroit locker. Just kicking all available options.

 

I ran a pretty warmed up Ford small block, manual 3 speed, and a hefty 16-25 yr old foot on a 19 spline Dana 44 for alot of years. Never broke a rear axle. That one had a powerlok early on and then an ARB Air Locker. In fact...It's the same rear end that's in my CJ-6 now. It's bent, but not broke. lol