9 Inch Ford Cut-to-Fit Axle Kit, Big Ford/New Style, 31 Spline
Ford 9 Inch, 31 Spline Count, Multi: 5 on 5" | 4.75" | 4.50" Bolt Pattern, Steel
- Allows you to build your own custom width rear end easily
- Includes two 31 spline cut to fit axles, long axle length 33" and short axle length 29.51"
- Premium steel construction for consistent performance and reliability
- Axle has the new style big bearing Ford (Torino style) bearing size
- Features three bolt patterns 5 on 4-1/2", 5 on 4-3/4", and 5 on 5"
Build Your KitYou're almost there! This kit has an option or two for you to select. Let us know which options you want for your new kit.
These steel axle shafts have a natural finish and are sold as a pair. They are perfect for small shops and will allow you to build your own custom width rear end easily. Axle length is measured from the flange to the end of the splines.
- Circle track / off road application 5/8" thread wheel studs sold separately 910-05957 and 910-05958
- Street application 1/2" thread wheel studs sold separately 910-05959 and 545-46190
- 9 Inch Ford
- 31 spline axles
- Long & Short axles included
- Axle has the new style big bearing ends on it
- Bearing measures 3.150"
- Bearings already pressed in
- 2-1/2" Offset
- Drilled for 5 on 4-1/2", 5 on 4-3/4", and 5 on 5" wheel bolt patterns using 0.685" knurl dia.
- PA20 set bearing
- AR375 Torino retainer
- Axle length is from the flange to the end of the splines
- Axles have 3 bolt patterns in them: 5 on 4-1/2", 5 on 4-3/4", and 5 on 5"
- The hub pilot (center of the axle flange) measures 3.055"
- The O.D. of the axle flange measures 5.93"
For more information on determining the proper axle length and the Ford 9 Inch, be sure to check out our tech articles; How to Measure and ID Differential Housings and The Rearend Debate: Ford vs. Chevy.
- 33" length with 9-1/4" of spline
- 29.51" length with 10" of spline
Also available for consideration when a replacement axle bearing retainer for either of the following Ford applications may be required:
Disc brake kits may require increasing the i/d of the center hole in the rotor to match the o/d register or hub pilot on the axle flange, or reducing the diameter of the register or hub pilot on the axle to fit properly to the i/d of the rotor.
When installing new axles in rearends with posi traction differentials, be sure to install the driver's side axle first to keep the splines properly aligned. Failure to do so may move the two splined gears out of alignment, and it may be difficult to install the driver's side axle properly if the passenger side axle is already installed.
If installation of passenger side axle is done first it may require two people when installing the driver's side axle, with both parties rotating reach axle until splines are in line and the driver's side axle fully sides into the housing.
When cutting axles to desired lengths, it is recommended that the following procedures are performed:
- Normal steel cutting machinery (cold saw, band saw, chop saw, etc.)
- Using a sleeve around the axle such as a small piece of PVC tubing - this allows:
- The axle to be spun in place while being cut
- A perimeter cut around the outer diameter assisting in keeping the cut square
- Avoiding the build-up of too much heat by doing a straight cut (like a knife though a stick of butter)
To ensure you get the most out of your new 9 Inch components, it is recommended that you perform a proper break-in process:
- Use a name brand mineral-based gear oil, preferably 85w140 (Extremely high quality synthetic oils may be used once break-in process has been successfully performed)
- Place vehicle on jack stands and let the rearend spin while the vehicle idles - run transmission in both forward and reverse periodically throughout the process
- Continue to run the rearend until the pinion gets hot (place hand on bottom of the differential housing to verify this)
- Proper break-in allows:
- The ability to install new axles and hit the track the same day without worry
- Extended life for rearend components
- Keeps the quality and life of your gear oil
- Get FREE shipping when your order includes this item and exceeds $99! Ground shipping only in the contiguous US.
What's In The Kit
Short 31 Spline 9 Inch Ford Cut-to-Fit Axle with BearingPart # 91045127-31-SHORTQty x 1
Long 31 Spline 9 Inch Ford Cut-to-Fit Axle with BearingPart # 91045127-31-LONGQty x 1
Q & A
Check out our 6th episode of the 410 Sprint Car Build series. Last time we assembled the rear axle and now we are installing it!
Today on our 410 sprint car, the guys are assembling the front axle. The process can be a bit messy, but the finished product is so worth it!
Pat talks about our 67-72 pickup rear end housing and some of the options we have for it.
When it comes to a traditional style build on an early hot rod it just has to be rolling on a solid front axle of some sort. In this buyer's guide we take you through I-beam and round tube solid axles, spindle choices, radius rod needs, and more.
In this Tech Tip, John responds to a customer looking to upgrade the 8” stock differential in his Cougar to a 9” open diff.
A routine weekly maintenance checklist to perform between each race in order to keep a clean and efficient race car at the track.
We will show you the differences among traditional I-beam and tube axles and suspension designs used on hot rods; the differences between cross and traditional steering, measuring for springs, what spindles to choose, and much more.