|
|
How To - Install A Five-Speed TransmissionModern Driveline is an excellent resource for five-speed manual transmission conversions for classic Mustangs From the December, 2011 issue of Mustang Monthly By Miles Cook Photography by Miles Cook
|
|
If the vintage Mustang you’re driving still has its original transmission, then your freeway performance is not anything like an ’83 or newer Fox, SN-95, or S197—all of which have an overdrive gear ratio for Fourth, Fifth, or Sixth gear, depending on if the car has an automatic or manual. Whether manual or automatic, pretty much all vintage transmissions have a final drive ratio of 1:1. Even with a relatively tall 3.00:1 rear-axle gear ratio, you’re still spinning about 3,000 rpm—or maybe even more—just to maintain a 65-75-mph speed limit. If you’re trying to keep up with your buddies who are equipped with overdrive, you can forget about it. They’ll just pull away from you like you’re hauling lumber. If your vintage Mustang is an around-town grocery getter that makes it to an occasional cruise night on the weekends, then a final drive ratio of 1:1 probably doesn’t bother you very much. On the other hand, if you like to drive your ’65-’73 Mustang on the open road, then the addition of overdrive will convert your car from a freeway buzz-bomb into a quiet and smooth ride than can accomplish a 500-mile day with ease. If you’ve never experienced a vintage Mustang or other early Ford with an overdrive gear, you should definitely try out a friend’s conversion because it will seem almost miraculous as the transmission shifts into top gear and the tachometer drops from 3,000 rpm or more down to around 2,000 rpm or less. If you’ve had enough of the right lane and you’re ready to turn your car into a freeway flyer, then an upgrade to a manual-shift overdrive gearbox is the solution. There are several different types of five- and even six-speed manual transmissions out there, but the T-5, as used in ’83-’93 Fox-body Mustangs, is the most popular. For price and performance, it’s hard to beat this time-tested and continually improved gearbox. One of the more interesting cars we’ve seen lately is our nearly perfect ’65 Mustang fastback subject car dressed up as a Shelby GT350 replica. The car was equipped with a C4 three-speed automatic, so it was an ideal candidate for a T-5 five-speed conversion. We were reluctant to take this car very far from home because of the 1:1 final drive ratio. An hour or so on California freeways, with the tach reading 3,300 rpm trying to stay in front of the trucks that were blowing by us, got old pretty fast. We solved that problem by contacting Modern Driveline. The company is a recognized leader when it comes to vintage Mustang manual-transmission conversions, and owner Bruce Couture has carefully engineered the company’s T-5 conversion kits to install easily and fit right the first time. Only the most reliable components are used in the creation of its setups. Join us and we’ll show you how to install one in your ’65-’73 Mustang.  1 The heart of the Modern...  1 The heart of the Modern Driveline conversion kit is a new Tremec T-5 “Z-trans” (referring to Ford Racing’s M-7003-Z) five-speed gearbox. The gear ratios are 2.95:1, 1.94:1, 1.34:1, 1:1, and 0.63:1. The transmission also features double moly hardening on second and third gears and on the countershaft as well. This transmission is rated to handle 330 lb-ft of torque. Also shown is the Modern Driveline conversion crossmember and transmission mount.  2 We used Modern Driveline’s...  2 We used Modern Driveline’s optional kit that features a capacity of 450 horsepower. It upgrades the package with a Kevlar clutch kit and a lightened billet flywheel. Both are shown here as well as the hydraulic clutch conversion kit. If you are converting an automatic car, then Modern Driveline also has manual transmission pedals available for ’65-’70 Mustangs.  3 This Quick Time steel bellhousing...  3 This Quick Time steel bellhousing is also an upgrade from the standard T-5 bellhousing, which is an aluminum casting. The QT piece is far stronger and is SFI certified at 6.1. The QT housing also saves 20 pounds when compared to a conventional scattershield. The rings at the bottom are adapters that allow the bellhousing to be used with several different transmissions. Available at Modern Driveline as part number MD-401-6065, the bellhousing includes an engine-block plate.  4 Beginning inside the car,...  4 Beginning inside the car, the automatic-transmission shifter is the first thing to go.  5 Underneath the car, remove...  5 Underneath the car, remove the driveshaft. We’ll shorten it by one inch and then have new u-joints installed. You may also have to remove your car’s exhaust system for clearance when removing the transmission.  6 Remove the small inspection...  6 Remove the small inspection cover and disconnect the flexplate from the torque converter by removing the nuts on the studs welded to the converter. You’ll need to rotate the engine in order to access all the studs.  7 With the transmission supported...  7 With the transmission supported by a screw jack, the bellhousing bolts are removed. Next, the stock transmission crossmember is removed, as seen here.  8 Here, the C4 automatic...  8 Here, the C4 automatic transmission is lowered out of the car. The transmission jack will also come in handy when installing the new gearbox because precise positioning is required.  9 Next, we used a cut-off...  9 Next, we used a cut-off wheel to remove the automatic transmission kick-down lever from the throttle linkage. With a manual transmission, the lever is no longer needed.  10 Here, a new pilot bearing...  10 Here, a new pilot bearing is installed into the recess in the crankshaft. This bearing replaces the standard solid bushing normally used. No bearing or bushing is needed for automatic transmission applications.  11 Next, the new billet flywheel...  11 Next, the new billet flywheel is installed onto the crankshaft. Red Loctite was used on the bolts and they were tightened to the correct torque specifications, which is about 50-70 ft-lb depending on the application.  12 Install the Kevlar clutch...  12 Install the Kevlar clutch disc into place on the flywheel and retain in the correct position with a clutch alignment tool. Make sure the alignment tool isn’t drooping when tightening the pressure plate fasteners. Here you see the torque wrench being used to bring the fasteners to the prescribed value of 25 ft-lb.  13 We also did a quick check...  13 We also did a quick check of the adapter rings to be sure we used the correct one for our transmission.  14 Here, the throw-out bearing...  14 Here, the throw-out bearing is installed onto the new clutch fork. Before the fork is installed onto the bellhousing, the ball stud will receive a small dollop of heavy grease. Don’t use too much because you don’t want excess grease getting onto the clutch.  15 We topped off the new...  15 We topped off the new five-speed with Castrol Dex/Merc automatic transmission fluid. This lubricant has the correct viscosity for a T-5. Do not use the regular weight gear oil found in a Top Loader transmission. Regular weight gear oil will ruin a T-5 because the viscosity is too high to allow cold circulation to needle bearings and other small moving parts in a T-5.  16 After installing the Quick...  16 After installing the Quick Time bellhousing onto the engine, the gearbox was supported with the screw jack, then the T-5 was hoisted into position and slid forward to seat against the face of the bellhousing. Raise the transmission and move it forward toward the bellhousing in small increments. We would say that, from a safety standpoint, the transmission is too heavy to do this by hand. The four heavy bolts fastening the transmission to the bellhousing were then installed.  17 Install the rear transmission...  17 Install the rear transmission mount onto the tailshaft housing. Once the mount is secured, the Modern Driveline crossmember is put into place, as shown here.  18 Using the supplied through-bolts...  18 Using the supplied through-bolts with nylon lock nuts, the ears of the crossmember are attached to the car. The final step in securing the transmission is the installation of the two nuts on the transmission mount studs.  19 We had the driveshaft...  19 We had the driveshaft shortened by one inch and new u-joints installed. Here, the shaft is being balanced for vibration-free operation.  20 We selected the correct...  20 We selected the correct speedometer drive gear for our 3.00:1 axle ratio and installed it onto our speedometer-drive cable. Remove the red plug and install the cable and gear into the transmission.  21 Next, the mounting bracket...  21 Next, the mounting bracket for the hydraulic clutch slave-cylinder is installed onto the side of the transmission.  22 Using the supplied fine-thread...  22 Using the supplied fine-thread fasteners, the slave cylinder is installed onto the mounting bracket.  23 Next, attach the hydraulic...  23 Next, attach the hydraulic clutch lines. This line goes from the slave to the master cylinder. We covered the master cylinder end of the line with tape, secured it under the hood, and moved up into the interior of the car.  24 Inside the car, two fasteners...  24 Inside the car, two fasteners are used to install the vintage-appearing shift handle. The boot will be secured to the floor with four sheetmetal screws. The shifter clears the hole just right, so we didn’t need to enlarge the opening on this car. The down side of not enlarging the opening is that in the unlikely event you’ll need to remove the shifter, it cannot be done without dropping the transmission.  25 We need to reduce the...  25 We need to reduce the size of the brake pedal to the manual transmission dimension to make room for the clutch pedal. Mark the pedal for the correct size and make the required cut with a cut-off wheel. You can also replace the pedal with a manual version.  26 An open spot was located...  26 An open spot was located on the firewall and the hydraulic-clutch master-cylinder reservoir was installed using the two supplied fasteners.  27 Use the supplied template...  27 Use the supplied template to determine the correct location for the hole needed to mount the clutch master cylinder.  28 A one-inch hole-saw was...  28 A one-inch hole-saw was used to create the needed opening for the clutch master cylinder. Here, you can see the aluminum spacer in place over the opening.  29 Using the furnished fasteners,...  29 Using the furnished fasteners, the master cylinder is permanently installed onto the firewall. A special backing plate is used on the inside of the firewall.  30 Shown here is the master...  30 Shown here is the master cylinder backing plate installed with its linkage. All geometry is worked out to insure the correct amount of travel at the master cylinder.  31 We removed the protective...  31 We removed the protective tape from the fluid line coming from the slave cylinder, then completed the important connection to the output of the master cylinder.  32 Here, the hose from the...  32 Here, the hose from the fluid reservoir is attached to the correct inlet on the clutch master cylinder.  33 The new clutch pedal arm...  33 The new clutch pedal arm is next, shown being lifted into position on the pedal mounting bracket.  34 Shown here is the pedal...  34 Shown here is the pedal in the installed position on the car. Notice the rubber stops to limit upward travel of the pedal arm. The pedal height can be adjusted by adding or subtracting shims.  35 Here’s an interior view...  35 Here’s an interior view of the pedal arm showing the completed installation of the fully adjustable linkage. All that remains now is to fill the fluid reservoir and bleed the hydraulic clutch system per the instructions. The system will not operate properly until the system is completely purged of any air bubbles.  36 Here’s the completed Modern...  36 Here’s the completed Modern Driveline installation with the exhaust system reinstalled. It’s a super clean setup.  37 Inside, the shifter and...  37 Inside, the shifter and pedals looks original-equipment correct. The only tip-off is the Fifth-gear shown on the shift-knob pattern. Now hitting the freeway again in this freshly restored Shelby clone will be a considerably different experience.
|
|
|