At the front pump, there's a brass bushing used to prolong service life.A small cut is made to the leading edge of the pump crescent. Thisquiets down the characteristic whining sound the C6 transmission makesat idle. A later model pump stator is used with CPT rebuilds becausethis stator offers improved lubrication qualities. Better lubricationand pump pressure means longer transmission life.
With the billet servo assembly installed into the transmission case, wecan proceed with the intermediate clutch band. Band tension is adjustedafter assembly at an adjustment point outside the transmission case. | 
A small bevel cut is made to the leading edge of the pump crescent. Itmakes the transmission much quieter at idle. | 
Once the front pump is assembled, it's easy to see how the bevel cutworks in quieting the transmission. The pump's G-rotor teeth no longersnag on the leading edge of the crescent. Smoother operation meansquiet. |
Another durability improvement California Performance Transmission usesis special Teflon rings on the pump stator shaft, as well as the forwardclutch drum. The original steel rings are prone to excessive wear andhave a way of creating grooves where they aren't wanted. We tossed them.
The stock C6 valvebody is used, but it receives several modifications toreally be effective. Some are in-house secrets that we can't tell youabout. What we can say is CPT uses a larger accumulator spring forfurther improved second gear shift firmness. A larger pressure regulatorspring is used to increase line pressure, which also improves shiftquality and firmness. Further, CPT enlarges certain oil passageways inthe custom valvebody separator plate that improves high-gear shiftfirmness.
These Teflon rings are used on the pump stator shaft and forward clutchdrum to prolong service life, prevent scoring, and eliminate leaks. | 
The CPT-modified valvebody is ready to install onto the transmission. Bymodifying the valvebody separator plate, the transmission can beprogrammed to match your application exactly. | |
Improvements to a CPT rebuild don't stop here. CPT also makes its ownhigh-performance torque converters in-house. They don't use inexpensivemetric converter covers, but rather they use their own assembly thatprovides a stall speed of about 2,500 rpm, depending on your performanceneeds. Stall speed is where the torque converter begins to transferengine power to the transmission. Choose your stall speed based on whereyour engine makes power. Street applications need a stall speed around1,800-2,500 rpm. Racers need higher stall speeds to get the engine intothe power band before torque multiplication and power transfer happen.
This photo shows the factory plastic stator used in the original torqueconverter next to the CPT steel replacement. The steel part used by CPTenhances durability inside the torque converter and prevents bending orshearing of vanes. Simply put, this is a bulletproof torque converter. | 
Here's a CPT torque converter opened up so we can see the heavy-dutyconstruction. CPT converters feature 4340 steel shaft and pump hubs. Allfins and impellers are furnace brazed and welded for optimum strength. | 
With the transmission assembly nearing completion, the valvebody isinstalled. A standard or reverse pattern valvebody can be specified, andmany modifications are possible. CPT has some in-house secrets that theyuse in the preparation of automatic transmission valvebodies gained fromover 50 years experience. |
One more high-performance trick CPT uses is a deep sump finnedtransmission fluid pan. The additional fluid volume combined with thebroader surface area provided by the fins means a cooler runningtransmission. We would recommend the use of an external cooler, as well.the cooler your C6 runs, the longer it will live. | 
With the torque converter installed, our heavy-duty C6 transmissionbuild is complete and ready for big-block power. All of theseimprovements combined make for a Ford C6 automatic gearbox that shiftsbetter, is much stronger, and far more reliable than the stock versionof this excellent transmission. | |