Astro Performance T5 Manual Transmission - Standard Shifting Procedures

For our transmission, we went with the upgraded A-5 0.79-percent Overdrive gearset, which was installed on the respective shafts.

Here is the installed Fifth shift fork and synchronizer assembly on the cluster shaft Fifth gear.

This is an internal view of the assembled A-5 gear kit and components that we used to beef up the stock T5 transmission to 525 lb-ft of torque.

After the top cover is in place, Astro recommends putting RTV silicone not only on the tailshaft housing face, but also on the rear of the top cover where there is an O-ring. Issues in the past with leaks prompted Astro to use silicone around the outside of the O-ring on all rebuilt transmissions.

The last step in the A-5 gear kit upgrade was to remove the all-steel bearing retainer from the front of the main case to seal it and set the end play. As with the cluster shaft, Astro wants no endplay, however, the input shaft should not be shimmed so tight that you can't turn it.

Here's our complete Astro A-5 five-speed transmission that is capable of handling 525 lb-ft of torque and 650 hp. With the upgraded Fifth gear, our unit retails for $2,195. You'll need to fill the A-5 gearbox with 2 quarts of the Synergen, topped off with about half a quart of Mobil 1 synthetic ATF.

Hoffman (left) and Sarvis (right) can build just about any manual Mustang transmission you need, whether it's a stock rebuild or a stout stick box for your street/strip terror. If you're doing the wrenching on your transmission, they can also provide you with all of the parts you may need. Sarvis is a great source of knowledge when it comes to transmissions and was a great help in writing this story.

From Centerforce Clutches comes the LMC clutch and pressure plate. LMC-or light metal clutch-is Centerforce's low-inertia performance clutch. Manu-factured from high-strength billet aluminum with a riveted heat shield, this new series of light metal clutch pressure plate reduces rotating mass and uses a dual-puck-style disc and a patented ball bearing- actuated diaphragm that reduces pedal pressure while increasing performance and holding capacity. We will also employ one of Centerforce's aluminum flywheels to drop even more rotating mass.

Stolen Goods has to get the power back to the rear axle somehow, and we didn't see any reason not to use an FRPP aluminum driveshaft. They're inexpensive and lightweight and will handle our engine's power level perfectly. We ordered ours from Texas Mustang Parts in Waco.