3198BullittBob

When inspecting the Ford 9 inch rear, how does one determine if it is 28, or 31 spline without taking apart? Thank you.

Yonco

I was thinkin the same thing. I think the only way is to undo the 3 bolts behind the bearing on the end and slide it out and see, but i dont want it to leak any fluid, so im not doing that. -Jon

68SCode4speed

Isn't the hub face on the outside of the axle dimpled one way or the other???

chillininnh

I believe the only way to tell is to slide the axles out and count the splines. Not many cars came original with the 31 spline axles. Big block cars got them and maybe the Boss 302 and probably some trucks.

Yonco

Mine was put in by the owner before me so im not sure and neither was he! -Jon

Scott H.

Great reference material for the Ford 9". He also has what appears to be a nice swap for disc brakes on a 9".

http://www.ultrastang.com/Rearinfo.asp?Page_ID=1#

There is a lot more than just this one page. I'd suggest perusing his whole site. It's very well done.

69mach1377

3 bolts? 4 IIRC. You shouldn't leak much if any. You could always have the other side lower if you truly fear this...

3198BullittBob

Thank you all for your feedback. I guess The only real way to determine 28, or 31 is ti pull an axle out and count .

69mach1377

Might as well count if it is out, but 31s have no taper to the shaft, while 28s do neck down some.