31 spline axles

[winr]

Anyone have 31 spline axles in their 9" rear end ??


Or come across any 31 spline axles that fit up 1972 Ford trucks ??


I have 3 3rd members, all 31 spline and my truck has 28 spline axles.


Richard.

[OLE69F100]

I have a 31 spline in a 9 3/8" rear. I am not sure if they would fit but someone might.

[old timer]

most all the four wheel drives I've run into have 31 spline axles

[F100builder]

I don't know about the 4WD's but I don't think that Ford used 31 spline axles in the 9" pickups (2WD anyway) until the dentsides came along. I'd like to know if there is a 31 spline axle that's the correct length for a bump's housing. I do know you can't put dentside 31's in a bumpside's housing even if you change the pumpkin to a 31 spline differential as those axles are too long.

[Rockcrusher]

There are two bumpside 31 spline axles that I know of . . . Both were 9.375's.

WEY axles were open and WFF's were limited slips.

-A . . . 3.25:1
-B . . . 3.50:1
-C . . . 4.09:1

[F100builder]

But not 9" rears.

[convincor]

I'd like to know if there is a 31 spline axle that's the correct length for a bump's housing.

Me to.. I haven't had a chance yet but plan on looking into it once I pull a axle out of the 68 and measure it up.
But it really doesn't matter to me because I'm planning custom axle anyway. I've got a 31 spline Currie trac/lock and want to convert to 5 on 4-1/2" also due to wheel options.. But I'll check it out..

[F100builder]

I found another link here. It says (post 14 in the thread) that '71-'73 Mustangs have the same housing width. However, the passenger car 9" rears had two different length axles because of the off-center third member. In addition, I'm not aware of any 31 spline '71-'73 'Stangs. I know some of the bigger muscle and passenger cars (Torino, Galaxie, etc.) had 31's but not sure of the length.

Here's the link:
http://www.fordification.com/forum/view ... hp?t=27351

It sure would be nice to just swap the axles and pumpkin. I've already got new spring perches welded to a dentside housing for bolting it into my bump so I guess I'll continue with the shock mounts and just finish it. It's got equal length 31 spline and a Trac-Loc 3.50 diff.

[AlleyCat]

I have heard there were 31 spline axles used in bumps but I've never actually seen one.I was told 71 & 72 used them with limited slip rears.My 72 has a 9" limited slip but the tag is gone so I'll have to pull an axle to check.I plan to do the dentside housing swap this coming winter.With a little luck I won't have to build a center section.

[averagef250]

I've seen several of them. My '70 F-100 had a 31 spline LS 3.50 big bearing.

It's very easy to tell if a bumpside has a 31 spline 9 inch under it. If it does, it clearly has a big bearing housing that's a lot different from the little 28 spline one.

[Wes]

If ya want to run 31 spin axles you can swap the pinion side gears out

[F100builder]

If ya want to run 31 spin axles you can swap the pinion side gears out

Good idea. I guess I never thought of that.