59" Center Ford 9" axle length?

[WEBSTER51]

I have a 59" centered rear end what size axles should I run? I was thinking 31" lr and 32.5 rr third member is a full spool and I have sw speed hubs if that makes a difference. Looking for any input thanks!!

[speedbuggy]

This is a question that I always get confused about, too. My thinking is that you measure axle width from wheel mounting surface to wheel mounting surface. Also, you measure axles from wheel mounting surface to the end of the splined end.

If you measured in those terms for the example above, there is no way you could put those axles in that housing because 31 + 32.5 = 63.5. The axles would touch in the middle before the bearings would get close to the housing mounting flanges.

My thinking is for a centered housing, you need something like 1.0-1.5 difference in the axle lengths for a full spool and 1.5-2.0 inch gap for a mini-spool (gotta have room for the pin). I am talking about the gap between the axle ends in the center when the axle bearings are fully seated in the ends.

Following that logic, my suggestion for the above question would be a 30 and a 28 for a full spool, and 29.5 and a 27.5 for a mini-spool, give or take a half inch.

You fellers that know this stuff, help us out.

[speedbuggy]

whoops....now that I re-read his post, I see that he is talking about a floater. I was talking about a semi-floater...

[WEBSTER51]

I know When flush with the axle cap the 32.5 is in the third member about 1" so guess ill stick with that and run a tape down the lr axle tube till it hits the rr axle and measure the distance from hub face/axle cap to get the length of axle I will need?

[racin6mod]

I know When flush with the axle cap the 32.5 is in the third member about 1" so guess ill stick with that and run a tape down the lr axle tube till it hits the rr axle and measure the distance from hub face/axle cap to get the length of axle I will need?

the hubs and drive flanges make a difference in the axle lengths. not knowing the info of those makes it impossible to know how long each axle needs to be.

[Lizardracing]

Ford 9 inch is 4 inch offset from axle centerline to pinion center.

I would mount both hubs with just bearing and snug up the spindle nut. Remove the axle end caps if installed. Run a tape measure all the way through from cap to cap and note that measurement. Divide that by two. Subtract 2 from one axle and add 2 to the other.

So example if your measurement is 62 from cap to cap,
31=(62/2)

29=(31-2)
33=(31+2)


To make them perfect fits.....Subtract 1/2" from both axles. in this case that's 28.5 and 32.5. Thread a (5/16 fine threaded)nut onto a (5/16 fine thread) bolt. Thread both of those into the end of the shortest axle(spool end) and use it as an adjustable spacer between the two axles to keep the splines in the drive flanges fully engaged. 1/8 play is acceptable or 1/16 per side, cap to to axle end clearance.