Swapping a T5 overdrive manual transmission into an early Mustang or Falcon (or their Mercury cousins) has never been more popular.
We first did this swap in our ’67 Mustang several years ago, but since then countless others have also made the conversion to the modern-day five-speed for the sake of better fuel economy and faster acceleration.
For many of you, the swap was a no-brainer -your car was already a manual and you simply purchased the necessary conversion parts, the T5, and bolted it up.
Your mechanical clutch linkage worked just fine, though not nearly as smooth as the cable or hydraulic mechanisms typically found in a late model, T5 equipped, Mustang or Thunderbird.
For some of us, the conversion was a little more challenging due to the fact our cars were originally equipped with an automatic transmission. Hence we had to source the rare, and expensive, clutch pedal and associated linkage. Many of us ended up modifying parts from other model years or scrapping the swap altogether. Undoubtedly there are a good number of people still on the sidelines waiting to get into the T5 game but are unable to due to the growing scarcity of mechanical linkage components for their vehicles.
Regardless of which group you are in you can now bring your early Ford another step closer to the ease, practicality, and fun of an overdrive five-speed.
Modern Driveline has spent the last several years perfecting a clutch cable conversion kit for ’65-’68 Mustangs and Cougars and ’60-’65 Falcons and Comets.
The kit replaces all the original mechanical linkage between the pedal and the bellhousing. The only stock piece required is a clutch pedal.
The cable conversion kit is designed to work with any of the late model transmissions using a cable-actuated bellhousing (i.e. T5, T56, TKO)
In theory, the cable kit could work with any manual transmission, however, because the early Toploader and Borg Warners use a “push” style clutch fork, the bellhousings have no provision for mounting the cable-actuated fork.
There is no comparison between the pedal effort of an early mechanical clutch and that of the cable clutch mechanism found in newer cars. Cable clutches offer a huge reduction in friction and force required to depress the clutch. Furthermore, they are much easier to set up and adjust than their mechanical counterparts. Combined with a late-model diaphragm clutch the pedal effort of a cable is nearly half that of a long style pressure plate and “z” bar linkage.
The beauty of a cable is that it takes up very little space, and offers plenty of room for larger engine swaps, custom headers, or other atypical modifications that cause grief with the stock clutch linkage.
We’ve been considering a cable or hydraulic clutch conversion for quite some time. In the past couple of years, a handful of small vendors have developed kits, and we have taken them into consideration. Many of the kits required welding on the clutch pedal or firewall.
Some kits used an OE cable, while others had one custom-made.
The bottom line was the kits never seemed to be well thought out and designed.
We’ve seen many of the early designs lead to cracked or warped firewalls due to lack of load distribution.
We’ve also heard reports of poor clutch release due to improper leverage.
The Modern Driveline kit is by far the best-designed kit we’ve looked at. While it may require a little more time to install, the kit makes no compromises.
The cable passes through a steel bracket which not only distributes the load of the cable but strengthens the inherently weak firewall area behind the master cylinder.
There is no welding or modification necessary other than drilling a hole – making the entire project easily reversible if ever needed.
Follow along as we install the cable conversion kit into our ’67 Mustang
Modern Driveline claims 90 minutes to install the kit, however, that is assuming you have the T5 removed. You will need to install a cable-actuated clutch fork, as found in late model Mustangs (not included).
This requires the removal of the transmission and bellhousing.
Note if you have a T5 conversion kit that uses an adapter plate and original four-speed bellhousing, you will need to obtain a T5 or Lakewood bellhousing in order to mount the cable fork pivot.
Shown is the typical linkage from a 67-68 Mustang. The reduction in moving parts is astonishing: Upper and lower pushrods, “z” bar, upper and lower return springs, underdash bracket and spring, block and frame pivots, and special bellhousing pivot mount required when using late-model 302 blocks without a pivot mount provision.
With power brakes, you will most likely need to remove the entire assembly in order to get the bracket into place. You should only have to disconnect the two main lines at the master cylinder. Always use a flare nut wrench when removing brake lines.
18. Though not absolutely necessary, it is recommended that you use a late-model diaphragm style clutch. The release rate of the belvile springs are designed for a cable mechanism, whereas long-style “three finger” clutches are designed around mechanical linkage. If you do use the latter with the cable mechanism you should ensure there is sufficient fork travel to release the clutch properly, and also check for about 1/8″ air gap between the throwout bearing and clutch fingers when the clutch is engaged.
19. We ended up ordering a Stage 3 SPEC clutch. The clutch uses a diaphragm style pressure plate, which is shorter in height than a long style and thus clears up our cable length problems.
The SPEC clutch disc is composed of six carbon metallic paddles, and is rated to hold 600 horsepower, without the aggressiveness of the sintered iron we were using previously.
20. With the clutch and bellhousing mounted, the cable end is passed through the bellhousing flange.
Secure the cable to fork nut and jam nut.
Also if you get a clamp style booster you will likely need to reposition the clamp bolt to prevent interference with the cable.