It's all too easy to make horsepower these days: add more cubic inches, some boost, or nitrous, and the pocket book is really the only limit when it comes to making power. Likewise, technology has come a long way in providing reliable transmission of that increasingly greater number of ponies to the rear tires. Looking to back an old-school Nova's supercharged Gen-1 small-block with a formidable transmission, we dropped in on Monster Transmission in Brooksville, Florida, to see what goes into the company's SS Xtreme 700-R4 overdrive transmission.
Despite the Nova's high horsepower level, the owner still wants overdrive. Having overdrive provides improved fuel economy, and while one might think that shouldn't be a concern with a supercharged small-block in an old muscle car, it is if you're burning pricey high-octane race fuel. Even premium pump gas comes at a premium cost that gets higher every year, so let's knock down that highway engine speed, save a few bucks, and give your valvesprings a break.
When it comes to overdrive GM transmissions, the 700-R4 is the go-to gearbox for applications over 750 hp and where manual control is desired. Monster offers several levels of transmission builds, and the top-of-the-line unit is the SS Xtreme. This transmission offers full manual operation, which is not possible with the later electronically controlled automatic transmissions, such as the 700-R4's younger 4L60, 4L65, and 4L70 siblings.
Monster Transmission starts its SS Xtreme build with an 1987-or-newer transmission, as the basic internals in these were much better than previous models. Each case is cleaned, threads are chased, and then it is painted for a great-looking finish.
Kolene steels have been a key component in upgrading late-model transmissions, and Monster combines these with Alto's Red Eagle clutches. Both feature higher friction properties and increased heat resistance through the use of better materials and increased surface area. The greater heat resistance extends the life of the steels and prevents warping.
Monster employs a Sonnax input housing kit to remedy a number of common failures with the factory drum and input shaft. This modified input housing is treated to reduce stress cracking that can lead to housing fatigue and failure. The kit also includes a 300M alloy input shaft that is supported by a reinforcement sleeve to prevent the shaft from cracking the housing.
On the left you can see the stock snap ring beneath the Sonnax 3-4 clutch apply plate. The snap ring has been known to fail in high-horsepower applications, so Sonnax combined a stronger bolt-on anchor plate (right) with a thinner, yet stiffer apply plate that allows room for more clutches (eight instead of six).
Another set of upgrades to the 700-R4 is this pair of billet aluminum Second and Fourth gear servos. These pieces have been designed with more surface area that transfers a greater volume of fluid for increased clamping force on the band.
Pictured here is a stock Corvette servo on the left and the Monster Transmission billet unit on the right. Transmission fluid is forced out from between the two halves, and Monster's servo on the right offers more surface area allowing more fluid to apply to the band.
Center in this group of upgrades is the Beast, which is a hardened sun shell that Monster uses. The stock sun shell can often crack at the neck collar and strip the splines in it. The Beast features thicker material with a support weld around the base for greater strength. Also in this picture are the upgraded planetary gears. A stock GM 700-R4 transmission utilizes a four-pinion planetary set, and five-pinion gear setups are mandatory for any transmission that's dealing with 500+ hp. The extra gear increases the surface area and distributes the load with less stress on the individual gears. GM eventually went to five-pinion planetary units in its later electronic transmissions.
By going to a manual-style valvebody, the throttle valve (TV) cable is eliminated. With this change, the end user no longer needs to set the transmission line pressure via the TV cable, which can be tricky for some first-time transmission installers. The pressure on this manual unit is set inside the transmission and raised above the factory specification for improved performance.
In addition to maximum-effort transmissions, Monster can also supply you with a torque converter specific to your application. The SS Xtreme employs a non-lockup design, and the stall speed can be tailored to your drivetrain combination for optimum performance. Monster specializes in swapping its overdrive transmissions into pretty much anything, and offers transmission crossmembers and coolers, slip yokes, shifters, and more.
There are numerous upgraded components and tricks that Monster employs to get its SS Xtreme to handle such high levels of horsepower, and Monster Transmission's Tony Vargas showed us the hardware while we clicked the camera shutter. If your high-powered ride needs a tough overdrive transmission to let you cruise to your destination with ease, the SS Xtreme is a viable option.
The valvebody used in this build starts out as a stock piece. All of the mating surfaces are refinished and the channel areas are cleaned. To convert the valvebody to full manual, forward-pattern operation, a TransGo Reprogramming kit is installed. Modifications required for the reprogramming include changing springs, valves, and modifying the separator plate. An integrated constant-pressure modification is also made to eliminate the need for the throttle valve cable.
With the valvebody modifications completed, the front pump can be installed. For the SS Xtreme, Monster employs a 700-R4 heavy-duty pump that features updated springs, a 0.500-inch boost valve, a 0.300-inch low/reverse boost valve, a new 10-vane rotor, new stator bushings, as well as a heavy-duty hardened pump stator. The vanes and springs are heat-treated and modified for use with the constant pressure valve body. As with many of the other components in the SS Xtreme, the billet input shaft is equally up to the 1,000hp task at hand.
Finishing up the transmission build, the output shaft is a stock piece that has been inspected and resurfaced. Monster prefers to use premium cork gaskets versus neoprene ones, stating that the neoprene can be too hard, not seat well, and cause leaks. A deep pan is also recommended to hold a greater capacity of fluid. The larger capacity will withstand more heat and dissipate it faster.
We are using a 10-inch, 30-spline PP7702 unit with furnace-brazed impeller and turbine fins and a diode stator. This is a non-lockup-style converter with a stall speed of 3,000–3,500 rpm.
Our converter was modified with an anti-balloon plate like the example on the left. Otherwise known as a flange-reinforcement plate, an anti-ballooning plate strengthens the hub area and prevents flexing that can lead to cracking and eventual failure of the component.
When installing a torque converter, it's imperative to seat it properly on the input shaft so that it is fully engaging the front pump. Depending on the transmission, you'll feel two to three clicks as you spin the converter on the input shaft and it slides further on. Here, Steve Falco installs the converter prior to the transmission being installed in one of Monster's test vehicles.
All of Monster's transmissions are vehicle-tested prior to being shipped. This SS Xtreme unit that we have been following was installed in the company's 1968 Camaro packing a stroked and blown small-block—exactly the type of destination in store for this transmission once it is boxed up and shipped to its new home. End
