Overdriven Excitement - Mega Monster AOD Transmission Installation

With the flexplate in place, it was time for Mark and Demetri to hoist our Mega Monster in place...

...but first they had to install our new torque converter. What you see here is one of Monster Transmission's 1,800-rpm-stall units, which is 12-inches in diameter and built for street cruising and longevity. With an upgraded engine or a focus on drag racing, we would recommend running a higher stall converter, but this will be perfect for getting us up and running.

Depending on your luck, the alignment of the stars, and several other factors beyond your control, installing the actual transmission assembly can either go smoothly or it can be a test of patience. Luckily, Demetri and Mark were able to get everything lined up on the first try, and the converter, flexplate, and bellhousing all lined up immediately.

The C4-to-AOD conversion package also comes with a new crossmember, which is offset to allow it to bolt in the factory location on the chassis, while still being able to support the transmission. Not shown here is the transmission mount, which bolts to the tail housing.

Using the transmission jack to line everything up, Demetri loosely bolted the crossmember to the transmission mount and then slid the entire crossmember into place. Monster is even nice enough to supply new bolts, which we installed before lowering the transmission jack out of the way...

... but not before bolting the torque converter to our new flexplate. Actually tightening the nuts to the torque converter is simple, although rotating the flexplate to access the four studs can be tricky. We prefer to use the starter access hole and a large screwdriver or prybar to push the flexplate up and around, spinning the entire assembly.

With the torque converter bolted to the flexplate, Mark installed the dust shield and tightened down the block plate-to-transmission bolts. We should probably do something about that oil leak in the near future!

Luckily, the factory starter can be reused with this swap, which will save you some money. It bolts back in place with the factory bolts and uses the factory wiring.

Conveniently, the factory C4 shifter, which was built for a three-speed transmission, can be reused in an AOD application. Using the supplied, fully adjustable linkage (bottom), we will be able to control every gear change with our stock shifter and ditch the clumsy stock piece (top) in the process.

The adjustable gear selector bolts directly to the stock shifter assembly (top) and then to the Monster AOD transmission (bottom) using the supplied hardware.

It's impossible to install this piece without making some on-car adjustments, which is something we will show you how to do after we finish the rest of the undercar install.

One major difference between a C4 and an AOD, besides the obvious additional gear, is the use of a throttle valve (TV) cable. While the C4 relied on a kick-down lever to control the transmission during heavy acceleration, the AOD relies on a TV cable, which is adjustable, and controls line pressure and shift timing based on pedal position.

Installing the Lokar TV cable on the transmission is simple, as it bolts in the same place as the gear selector, although it faces down instead of up. Using an existing bolt in the transmission pan, Mark mounted the TV cable in place and then routed it up toward our carburetor.

Our '70 Mustang came with a transmission cooler inside the radiator and we chose to reuse it with our new AOD. If your project doesn't have a factory cooler, or if you are simply looking to upgrade, we recommend installing a standalone cooler.

Transmissions live and die by heat, so keeping the fluid cool is a major consideration.

Monster Transmissions' conversion kit also comes with a new dipstick, which installs easily and allows for simple fluid level checks from a convenient place in the engine bay.

One thing that doesn't ship with the Monster conversion is a new driveshaft, although it's possible to reuse your stock unit, if you are willing to have it shortened by an inch. If you are looking to upgrade, now would be a great time to switch to an aluminum shaft, for a little extra horsepower and weight reduction.

For budget reasons, we decided to modify our stock driveshaft, which Demetri was able to cut and re-weld, shortening it by an inch to make it fit perfectly between our factory rearend and new AOD transmission. With the driveshaft installed, we were almost finished under the car, so we lowered the lift and got to work in the engine bay.

As we mentioned earlier, one of the most important parts of this conversion is installing the new TV cable. Since we were using a Holley carburetor and an Edelbrock intake manifold, we chose to install this Lokar adjustable bracket and Lokar cable. Remember, setting up your TV cable correctly is essential to proper transmission operation, so take your time and make sure this is right.

As a baseline, you want the TV cable to be a little loose but almost snug against the transmission lever. Setting the cable too loose will result in sloppy shifts, a decrease in line pressure and, overtime, excessive wear and tear on the transmission. Having it too tight will make for firm shifts and slightly higher shift rpm, so the balance between adjustments must be perfect.

Happy with our initial adjustments, Mark began to fill the Mega Monster with Schaeffer's All-Trans Supreme ATF. This fully synthetic ATF is recommended by Monster for it's superior formulation and long life, which will keep our transmission running well for a long time.

With the installation almost complete, Mark jumped in our '70 Mustang and began shifting through the gears, to make sure our linkage was adjusted correctly. At first, we had our adjustable rod too long, which made it difficult to go into Reverse and impossible to go into Park. A simple twist of the rod shortened the linkage and allowed us access to all of the gears.

And with that, we were ready to get back on the ground. As you can see, the Monster Transmissions AOD conversion came with everything we needed for a quick and easy install. Not only did we not have to go near the junkyard for parts, but we're confident in our new AOD and can't wait to get it out on the road.

Last but not least, Monster Transmissions loaded our '70 Mustang onto its in-house Mustang Dyno and drove her through all of the gears, including Reverse, to make sure everything was operating properly. Believe it or not, Monster does this with every transmission it builds, so the customer can be sure it's in tiptop shape before it leaves the factory. For us, we're ready to get out on the open road, shift into Overdrive and start cruising!