A Guide to Manual Transmissions and Components
We all know that automatics are convenient, but there’s just something about the way manual transmissions connect you with your car that makes them appealing. As the driver, you have more input and say in what’s going on. You become a mechanical component of the driveline every time you push the clutch pedal and pull the trans into another gear. Using engine braking as you roll off the highway, holding it in second gear to build rpm on an entrance ramp, and the sheer thrill of the 1-2 speed shift that breaks the tires loose on the hit.
Years ago, racers chose manual transmissions due to their robust strength, being able to control the engine rpm at the launch and the fact that automatics were far from efficient nor practical in performance applications. Today, automatics can hold their own with sticks for the most part, but the venerable manual transmissions are still the choice for many a hot rodder and track racer.
Choosing a manual trans may not be for everyone, but if you enjoy stirring your own gears there are a lot of fun options parts available these days. From brand new four-speeds on up to six-gears with economy-boosting overdrives, hydraulic clutch setups, strong-gripping clutches and shifters, there’s never been a better time to drive a stick.
Lokar has been known for its high-quality line of automatic shifters for years, so it certainly made sense when the company introduced the AxiShift to stir manual gearboxes. The AxiShift allows you to position the shift lever to precisely fit your application and comfort.
Two attachment options are available, providing 360-degrees of rotation and 15-degrees of tilt so you can find the ideal location. The shifters are machined from high-strength steel for extreme durability and are available to bolt onto the control lever of a Tremec TKO 500 and 600. The AxiShift Pro is a complete assembly designed to replace the original control lever.
Bowler Performance Transmissions
If you’re looking to swap to a manual trans or upgrade from an old four-speed, Bowler Performance Transmissions serves as a one-stop shop. As an Elite Tremec dealer, not only can they get you the right five- or six-speed to connect to your engine, but they can supply a complete swap kit for your application.
Think about all the different parts you need to upgrade the transmission. We’re talking about the bellhousing, clutch assembly, a crossmember, and don’t forget a custom-offset shifter! Bowler has it all with one call. Plus, the Bowler team has experienced techs to help with any issues you may encounter during your swap.
Better & Stronger
Hanlon Motorsports, out of Elverson, Pennsylvania, has been adapting and building five-speed swaps for muscle cars long before it was embraced by OEM suppliers. They now offer an affordable alternative for a five-speed swap with their TREMEC 3650 conversion system.
The 3650 transmission enjoyed a 10-year OEM run in GT Mustangs ending with the 2011 model. Hanlon goes through the entire trans, updating the weak links with performance components and adds a billet adapter ring/cover plate allowing the trans to be used behind other engines. Three levels of builds are available, including a very economical starting point up to a trans that will handle up to 1,000 horsepower!
Inland Empire Driveline
So, your hot is all set with oodles of horsepower backed by a new five-speed and a fresh posi in the rear. But have you considered whether the link between the trans and the rearend can handle the power and pending speed shifts? You probably should check in with Inland Empire Driveline before dumping the clutch and grabbing those gears.
Inland specializes in transferring power with their custom driveshafts. Every driveshaft is built to order using steel, aluminum or even composite materials. They also manufacture a variety of forged chrome moly yokes to fit GM, Mopar, and Ford components and can help build your shaft every step of the way including polyurethane cushion center supports.
Sidebar: How to Measure for a Driveshaft?
Greg Frick, Inland Empire Driveline
“First, make sure the engine, trans, and rearend are mounted in their final location and have the vehicle sitting with all four wheels on the ground. Measure from the tip of the trans output shaft to the centerline of the pinion U-joint. Next, measure from the tip of the trans output shaft back to the seal on the trans housing. For the U-joint, measure between the pinion yoke centering tabs, then the U-joint cap seat.
“This information is shared on a printable form on the Inland website, which we recommend being filled out and sent in with your order. Other information includes the number of splines on the output shaft, the type of trans and the differential make and model.”
Two in One
If you’re making the move to a powerful LT1, Coyote or Gen 3 Hemi, Tilton Engineering offers a twin disc assembly that can handle the serious power of these modern drivelines. Tilton has applied their nearly 50 years of experience with racing clutches to develop their new ST-246 twin-disc clutch kit for the performance street market.
The assembly starts with an aluminum clutch cover that is shared with Tilton’s proven line of racing clutches. The assembly features heavy-duty straps that attach the pressure plate and floater plate to minimize noise. The ST-246 is available with either sprung-hub organic discs for the street or solid-hub cerametallic discs for street/strip applications. A billet chrome moly steel flywheel is also supplied.
Advanced Clutch Technology
In the Clutch
Choosing the right clutch for your hot rod, and following the installation process completely, is imperative in producing millions of trouble-free shifts. Advanced Clutch Technology, known simply as ACT, offers up to 28 different pressure plate and disc combinations to suit mild street rides to full-on track use.
ACT engineers every application including designing entirely new diaphragms and pressure plate faces. These components are all manufactured, never rebuilt from used parts, which is important in producing stronger torque holding capacities ranging in improvements from 20- to 400-percent.
Running the right oil is vital in the life and performance of your manual transmission. This isn’t exactly new news, but for the performance oil specialists at Lucas Oil, it is gospel worthy of spreading across the hot rod world.
Lucas offers their 85W-140 gear oil which shares the same technology they developed in making their popular Lucas Heavy Duty Oil Stabilizer supplement. This formula is fortified with special anti-wear agents and lubricity agents to control wear and drag as well as special additives to control heat which are not found in ordinary gear oils. The 85W-140 is ideal for performance hot rods, classics and on the track.
Even a major OEM understands the joy of driving with a manual transmission, which is why Ford Performance now offers the Gen 3 Coyote crate engine with a six-speed! We’re talking about the GT 5.0L from the ’18-’19 Mustang that produces 460 horsepower combined with a Tremec six-speed.
The Power Module, M-9000-PMCM3, is supplied with a complete engine controller and wiring harness to support the aluminum powerhouse Coyote as well as the six-speed, which features a 2.66:1 first gear ratio. The assembly comes with a Quick Time steel bellhousing, roller pilot bearing, clutch kit, and dual mass billet flywheel.
Sidebar: OD Results
Swapping to an overdrive will lower the engine rpm, which can save wear and tear on the driveline, on the driver (and passengers), and of course, improve your mileage. There are different overdrive ratios available in manual transmissions and to make the right choice, you’ll need to consider the axle ratio, tire size, and rpm/speed. As an example, following are the rpm results of a car with 3.55:1 gears, and a 28-inch tire while running at 70mph:
Final Drive Ratio…Engine RPM
McLeod Racing has been designing and manufacturing clutch assemblies and driveline components for years. (Maybe you’ve seen their president blast down the ¼-mile in their Top Fuel Funny Car?) All of that experience and passion flows right into their product development, even when it comes to muscle cars and street rods. Recently, McLeod partnered with Tremec to offer new transmissions with their specialty installation kits.
Each new Tremec install kit includes a TKO trans along with McLeod’s adjustable steel crossmember, speedometer adapter kit, IsoTech trans mount, pilot bushing, trick shifter, slip yoke, and reverse light harness. McLeod can also help direct you to the ideal clutch assembly and hydraulic clutch system.
Between the engine and the trans is that extremely important connection called the bellhousing. A bellhousing needs to be accurately designed in order to have the trans and clutch components aligned precisely. It also needs to be strong to keep your toes and legs safe in the rare case of a driveline failure (more so for racing applications). One company that lives up to each of these specs is Quick Time.
Quick Time bellhousings are designed for an accurate fit due to a unique manufacturing process where the cones are spun, not rolled or stamped. Built of high-grade steel, the assemblies deliver over 80,000psi strength, double that of other housings, and are 100-percent built in the USA. Working on something a little different? Give Quick Time a call to develop a custom assembly!
So, you’ve installed a new TKO five-speed in your Chevelle, but want to retain the factory console? Hurst Shifters has a solution with their Blackjack Shifter series of shifters, which are designed to position the handle location of many Tremec transmissions to fit OEM consoles.
The Blackjack Shifter housings are CNC-machined from billet 6061 aluminum, and then finished with a tough black MIL-Spec anodized finish. For positive-yet-quiet operation, a Delrin pivot ball is used along with hardened chrome moly pins. A Hurst-engraved chrome flat bar stick is provided and topped with a classic, muscle car style white shift ball.
Centerforce SST (Solid Street Twin)
Looking for a high-quality twin-disc clutch system that is ideal for everyday use yet can handle spirited excursions on the track? The clutch gurus at Centerforce offer their new Solid Street Twin system for engines producing 400 to 925 lb-ft of torque. The SST 10.4-inch discs utilize solid hubs to reduce the rotational weight on the input shaft for quick, clean shifts and the discs are built using high-quality friction materials for smooth engagement and longevity.
A lightened, billet steel flywheel is supplied for low inertia, resulting in quicker revs, while Centerforce’s effective anti-rattle system reduces any floater noise. The SST system includes a billet steel flywheel, two discs, a floater plate, pressure plate, pilot bearing, alignment tool, and ARP hardware. The SST is an economical choice for street car enthusiasts looking for a complete high-quality twin-disc clutch system that can also handle some track time.
Sidebar: Choosing a Manual Overdrive
Craig Meyer, Bowler Performance Transmission
“One important thing to consider is if you’re willing to cut up your car to make the trans fit? Most older cars do not have the tunnel space to accommodate a TKO or Magnum without making some sheet metal modifications or a custom crossmember.
“Next is how you plan to drive – casual weekend performance or more of a race car? If it’s for cruising and a few burnouts here and there, a Tremec TKO will support those demands and is a little smaller. If racing is more of a priority, the Magnum series is a better choice, but is a larger case.”
So, you really want to install an overdrive in your classic but just don’t want to deal with the modifications that come along with installing a modern five- or six-speed. The answer is simple: Gear Vendors.
The Gear Vendors Overdrive unit is a compact auxiliary transmission that bolts to the back of your existing trans (such as a Top Loader, Mopar 833, Muncie or T-10). From there, Gear Vendors can give your vehicle up to twice the forward gear ratios as it splits the gears, keeping the engine rpm in the powerband through the shifts and when it comes to shifting into overdrive, your 4.10 gears will cruise like 3.20s (or a set of 3.55s will cruise like a set of 2.77s). And all of these benefits can be yours without even pulling the bellhousing or moving your shifter.
Pick up a 6-Pack
Tremec transmissions, such as the TKO 500 and 600, are known for their robust quality and are favorites of hot rodders and builders, not to mention the Detroit Three for modern muscle cars. Tremec leverages this experience to serve the automotive enthusiast and sportsman racing communities.
When it comes to handling serious torque, the Magnum XL six-speed is up to task. The XL is ready to handle up to 700 lb-ft of torque and is available with either a 2.66 or 2.97 first gear ratio. The trans was originally designed as a performance update for the S197 Mustangs, so you know it is ready to handle some on-track abuse – it even comes with an SFI-approved steel bellhousing!
Whether you are installing a modern five- or six-Speed in your classic Chevy truck, getting the mechanical clutch linkage to work properly can be a challenge. In fact, most new engines don’t even have a provision for a mechanical clutch pivot ball! The modern alternative is to step up to a juice clutch system and American Powertrain has what it takes to complete the upgrade.
Their Hydramax clutch system is based on a unique adjustable master cylinder bracket, which can be set up to mimic any original clutch rod angle to produce a smooth, modern clutch feel without hacking up your firewall. The Hydramax systems are designed to work with original and aftermarket pedals and are available for most vintage four-speeds along with popular Tremecs, Richmonds, and other modern overdrive sticks.
After swapping a transmission, you’ll likely need to shorten the existing driveshaft or better yet, upgrade to a new one. If you’re going the all-new route, consider giving QA1 a look to learn more about their REV Series carbon fiber driveshafts.
Each REV driveshaft is custom wound at QA1’s Lakeville, Minnesota, facility with a resin specifically designed for high performance, resulting in an assembly that is lighter and stronger than aluminum or steel while providing dramatic safety benefits. Each driveshaft is balanced, torsion tested, and serialized before shipping.
Sidebar: Hydraulic Setup or Mechanical Linkage?
Matt Graves, American Powertrain
“Since you’re replacing an old four-speed with a modern-tech five- or six-speed, shouldn’t you upgrade the clutch actuation? There are a number of advantages to a hydraulic clutch, including improved clearance for the headers, cleaner engine bay, and no worn-out bushings or linkage to bend or contend with.
“With a hydraulic bearing you can set your depth with shims and make adjustments so you can get perfect clutch feel. Also, modern engines make a lot of power and need a dual clutch assembly and it’s very hard to get a mechanical clutch set up for these.”
When mounting your transmission to the crossmember, it’s important to use a strong mount to limit the movement of the trans, yet be able to isolate the vibrations and frequencies of the drivetrain. Energy Suspension offers a range of upgraded manual transmission options for classic cars and trucks that can easily handle the power of today’s powertrains.
One of the latest developments from Energy is a series of transmission mounts for Mustangs. They offer their durable Hyper-Flex Performance Polyurethane mount to replace the soggy OE rubber mount on ’79 – ’93 Fox bodies equipped with a T5 trans. They also introduced a new mount insert for ’15-and-newer Mustangs along with a shifter bushing set. Each mount is available in red or black.
Chris Alston’s Chassisworks
When you’re installing an aftermarket trans in a stock chassis, or even a custom chassis, you’re going to need to modify the transmission crossmember. Why try to modify an older, weak crossmember when you can install a new, stronger unit thanks to Chris Alston’s Chassisworks.
Chassisworks offers a long list of custom-fit transmission crossmembers that will fit perimeter straight-rail and X-style frames. The crossmember tube is 1-1/4- or 1 5/8-inch diameter and available in 2–8-inch drop versions. Each kit includes the crossmember, weld-in inserts, and mounting tabs that allow it to be used in frames with a maximum width of 46-inches.
Four On the Floor
It seems that four-speed manual transmissions just aren’t talked about much these days, but you just can’t go wrong with a classic four-speed. And when it comes to new four-speed gear boxes, you can’t go wrong with a Richmond Super T-10 trans. (If you’re looking for a five-speed, they also offer their NASCAR-proven Richmond five-speed.)
The Super T10 is an upgraded version of the famous Borg-Warner trans and is ideal for a muscle car, classic truck, or street rod. The T-10 is rated up to 375 lb-ft of torque, features a close-ratio gear set including a low first gear, along with a strong side lever rail shift mechanism. If you plan to see more track day use, consider the Super T-10 Plus with brass synchro assemblies and a billet front bearing retainer. The Super T-10s are available for Chevy, Buick, Olds and Pontiac V8s with several gear ratio combinations.
Looking for a short-throw shifter for a T5, TKO or T56 Magnum trans? Be sure to look check out Modern Driveline’s Quick-Stik. This well-engineered shifter was designed to reduce modifications to your floor or console and features a small top turret for improved clearance.
The billet aluminum assembly is light weight with plenty of strength to row the gears. The shifter stub has an offset of 2-inches forward or backward from the pivot point along with an optional offset toward the driver if needed. The shifter plates are anodized and easy to install with new hardware and a high-temp, lower-dust oil boot.