Ford 9 Inch Posi Differential 3rd Member
Ford 9", Limited Slip Differential Type, 1310 Yoke U-Joint Series, Standard Ring Gear Weight
- Get FREE shipping when your order includes this item and exceeds $99! Ground shipping only in the contiguous US.
- This item 91049345 is made to order. It will be shipped from our warehouse when it is produced.
If you’re looking for a complete third member for your Ford 9-inch rear end housing, but want the added performance of a limited slip differential, Speedway Motors now offers you a 9" Ford street 3rd member for your street rod, muscle car or truck. We start with a new reinforced Speedway motors carrier housing and then install bearings, seals, a heavy duty "Daytona" pinion support, a 1310-series yoke, and your choice of ring-and-pinion ratios. The 1310-series yoke is the correct size for many Ford applications with cups 1-1/16 inch in outside diameter and a span of 3-7/32 inch across.
Coupling this bulletproof foundation with our clutch style posi-traction differential provides a proven combination and a welcome alternative to locker & spool differentials which are often overkill and more expensive than the common street car requires. Based off of the original limited slip designs of the OEMs, these differential units provide the added benefits of millions of miles and decades of proven reliability. Speedway has taken this engineering to the next step in performance with increased clutch pressure and holding power, suiting it well for heavy duty street car applications.
- Clutch style, spider gear differential = proven reliability
- Forged steel case
- Heat treated spider gears
- Quiet operation, no clicking when disengaging for corners
- Spring loaded clutch pack with improved grip over OEM designs
- Proven reliability and economical design
- Ideal for street tires and medium horsepower applications
This differential has performed well in our Week to Wicked 1952 Chevy Truck, handling the job of transferring a 430 HP GM Performance LS3 to the ground. Speedway Motors continues to bring quality products at an affordable price to keep your project on the road and the race track.
Racing applications with 10.5” tires, drag radials or slicks are better suited for the more expensive locker and Powertrax style carrier designs.
All third members are assembled by our team of professionals and are delivered to you in a handy plastic carrying case, for an overall value that can’t be beat.
Available in your choice of 3.00, 3.25, 3.50, 3.70, 3.89, 4.11 or 4.56 gear ratio in both 28 and 31 spline.
*Note-When selecting ratio, be sure you are also selecting the correct spline.
Gear lube recommendations :
91044090 - For street and every day driving under normal conditions
91044140 - For extreme duty, towing or very hot climates
No warranty is offered or made for durability or specific performance. No warranty is offered for commercial, off road, street performance, or racing use.
- Differential Type:Limited Slip
- Housing Material:Cast-Iron
- Axle Splines:Select Spline/Ratio to see
- Gear Ratio:Select Spline/Ratio to see
- Yoke U-Joint Series:1310
- Yoke Width:3-7/32"
- U-Joint Cap Size:1-1/16"
- Ring Gear Weight:Standard
- Weight:78.55 lbs
- MFG. Part #:Select Spline/Ratio to see
- Sold in Quantity:Each
- Gear Material:Steel
As featured on Classic Truck’s Week to Wicked. Watch the transformation here!
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Q & A
Tim talks about our Winters quick change rear end & components.
Finally, Project Chevelle gets a real hot rod engine under its hood! And what about that flimsy old column shift three-speed? We've got that covered too.
Speedway Motors employees are committed to helping customers, as well as working on their own projects during down time. Follow along as our employee, Zach, rebuilds a 10 Bolt.
Lucas P. explains how to choose the correct part for a Ford 9" third member build in order to achieve a bulletproof rear. You will find specific recommended parts to use from Speedway Motors.
Diagrams showing the proper measuring techniques for axles and identification diagrams for the various 9-Inch housings.
A brief overview of the steps Speedway Motors takes to ensure you get a quality differential.
In this Tech Tip, John responds to a customer looking to upgrade the 8” stock differential in his Cougar to a 9” open diff.