Dale Amy
October 1, 2003

Horse Sense:
The laws of gearhead economics dictate that a wise man will always have a clutch that is just a tad weaker than his transmission, since it's far cheaper to replace and should act as a driveline fuse.

V-8 Mustangs and manual gearboxes go together like peanut butter and jelly, pizza and beer, bureaucrats and taxes. There's just something about a successful up- or downshift's orchestrated ballet of hand and foot that is deeply satisfying to the enthusiast's soul.

Pleasure aside, all the horsepower in the world is meaningless without some way of getting it to the wheels in efficient fashion, so it's important to understand the basics of power flow from the crankshaft to the rear-end. And, as with so many aspects of Mustang ownership, we're bombarded with options when it comes to upgrading clutches and cables, bellhousings, shifters, driveshafts, and of course, the transmissions. With all these thoughts spinning and meshing in our heads, join us now for a beginner's basic primer on stick-shift hardware and how it all ties together.

But first, we must give credit where credit's due. It seems that every time we want the straight skinny on manual gearboxes, we turn to Don Walsh Sr. at D&D Performance, both for his seemingly bottomless well of knowledge on the subject, and for his guru-like patience in dealing with our often-infantile questions and time-consuming photography. Gearhead, Mustang drag racer, and all-round gentleman, before retiring in mid-2000 to devote full time to D&D Performance's rapidly expanding business, Don was senior drivetrain and chassis engineer at Ford Motorsport SVO (now Ford Racing Performance Parts). This man genuinely seems to know at least as much about drivetrains as most people know about breathing. Don spent the majority of his corporate engineering career with Ford, but he also spent a few quality years with both Rocketdyne and TRW, working on propulsion systems for the Apollo space program. So, you see, he literally is a rocket scientist, and that's good enough for us.

No discussion of Mustang manual gearboxes would be complete without a quick mention of the manufacturer(s) involved. Back in the day, Borg-Warner and Tremec were competing entities, each building its own line of five-speed transmissions. Nowadays the two product lines are merged under the ownership of Transmission Technologies Corporation (TTC), so it's all one big happy family. For simplicity and familiarity, we may occasionally slip back to the old corporate names. Hopefully, TTC will forgive us.