Ford 9 inch Rear axles - 28 Spline vs 31 Spline

rsimoes · #1 (**permalink**) 02-03-2003, 02:42 PM

Is it worth the extra money to upgrade to a 31 spline axle?

I'll be running a 460 with 480 foot pounds of torque through a TKOII and 3.33 or 3.50 gears.

By the way, which gears do you recommend?
Is the Ford OEM Traction Lok a good unit?

B. SMITH · #2 (**permalink**) 02-03-2003, 03:05 PM

WITH THAT MUCH TORQUE AND A RELATIVELY LOW REVING ENGINE I WOULD CHOSE THE 3.33:1 GEAR.

ON STREET TIRES, YOU ARE FINE WITH THE 28 SPLINE. IF "SLICK" TYPE TIRES ARE IN THE FUTURE ARE IN THE FUTURE, UPGRADE THE SPLINES.

GOOD LUCK, B, SMITH

dan adams · #3 (**permalink**) 02-03-2003, 04:37 PM

I have moser 28 spline axles, ford trac lok,3:50 ford gear set.
My engine is a 535hp 460 with a wide ratio toploader trans.
It hasn't been on the road yet, couple of months to go. I am not
worried. But I will try to roll out, or at least load the drive train
before dropping the hammer.
Dan

ac andy · #4 (**permalink**) 02-04-2003, 04:07 AM

31 spline axles give more surface area for the diff centre to bind to therfore making a stronger combination.

Ron61 · #5 (**permalink**) 02-04-2003, 06:49 AM

Rsimos,

The ford trac-loc will work fine if you aren't going to race it hard or run slicks. I ran a Motorcraft trac-loc for a few years until I busted it and my stroker puts out over 500 pound torque. I figured with the light rear end I could get away with it and when I busted it the guy that built the Eaton unit up for me told me the down shifting I had done hurt it as much as the up shifts. But I don't drag race and am not dumping the clutch from a dead stop. When I had the Eaton unit done I also installed the 31 spline axels. The high performance big block Fords like my 1969 Daytona Torino Cobra came with the 31 spline setup from the factory. So the 28 spline would most likely be ok for you unless as stated above, you are going to really be banging gears and running slicks and drag racing.

Ron