This Allstar Performance mini spool is a 31-spline steel mini spool for Ford 9in differential housings. Unlike a fullsize spool, a mini spool replaces only the spider gears inside the stock carrier, keeping the factory ring gear and carrier in place while still locking both axles together for full power lockup. This gives drag racers and oval track racers a lower-cost way to eliminate differential action without swapping the entire third member.
Compatibility: Fits Ford 9in housings using the stock carrier and requires matching 31-spline axles. This is a mini spool, not a fullsize spool, and is a different design from the 28-spline mini spool ALL68121.
FAQ
What is a mini spool?
A mini spool replaces the spider gears inside the stock differential carrier, keeping the factory ring gear and carrier while locking both axles together.
What spline count is this mini spool?
31 spline.
What housing does this fit?
Ford 9in differential housings using the stock carrier.
How is this different from a fullsize spool?
A fullsize spool replaces the entire carrier assembly; this mini spool only replaces the internal spider gears within the existing stock carrier.
What material is it made from?
Steel.

