Step-by-Step: Upgrading a Ford 9" Rear Axle with a Summit Racing Ring and Pinion Set


Slide Show

You've been working on lowering your elapsed times all season—bumping up horsepower here, tweaking the suspension there, and practicing your tail off at test and tune night—when you hit that proverbial brick wall. No matter what you do, your ETs won't budge. What do you do?

Try a rear axle gear swap. Changing the gear ratio changes the effective drive ratio at the rear wheels, which ultimately determines how fast your car accelerates. And after all, ET is simply a measure of acceleration.

We decided to go the gear swap route with Summit's Chevy S-10 race truck. With a 383 cubic inch small block, Turbo 350 tranny with 6,200 rpm stall converter, ladder bar suspension, a Ford 9 inch rear axle with a 4.33 gear and a Strange spool, and 29 1/2 inch Mickey Thompson ET Drag slicks, the S-10 was running 11.30 second ETs. We figured a switch to a Summit Ring and Pinion Set with a 4.56 gear ratoio that would put the truck in the 11-teens.

The main slide show covers the Summit Ring and Pinion installation. But while we had the rear axle apart, we also upgraded the carrier assembly with a Strange aluminum pinion bearing support, and added a Moroso filler cap to the axle housing to make filling chores easier.

So, follow along and see what it takes to upgrade a Ford 9 inch for track duty--or any kind of duty, for that matter.

SUM-G7827Summit Racing Ring and Pinion Set, 4.56 Ratio, Ford 9 Inch
SUM-G7814Summit Racing Ring and Pinion Installation Kit, Ford 9 Inch
STR-N1923Strange 28-Spline Pinion Bearing Installation Kit, Ford 9 Inch
STR-N1922Strange Aluminum Pinion Support, Ford 9 Inch
MOR-85280Moroso Universal Filler Cap Kit, Steel Bung
RED-57904Red Line 74W90 Synthetic Gear Lube, Quart (3 Used)
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