***Hellcat vehicles ONLY / ONLY ZF8HP95 transmissions – If you have an 8HP90 you will need to update the planet ring gear to an 8HP95 style to use this part***
The 8HP series of transmissions is an amazing feat of engineering. The unit is lightweight, strong, and shifts amazing. Like so many other 5th generation transmissions the majority of its internal parts are made of cast aluminum. While extremely lightweight, cast aluminum does not have the strength of 7075 aluminum or steel.
This unit uses cast aluminum in a very wear prone area. In fact, it’s the first transmission we know of that uses aluminum as a clutch hub. It also uses aluminum as a splined coupling in the E clutch drum. This area is a major concern and it is very common to see either stripped splines, twisted splines or excessively worn clutch hub teeth. These issues are as common on the smaller 8HP45 as they are on the 8HP95.
Our design features a 7075 billet aluminum clutch hub. This hub will greatly resist deformation where the steel plates contact it due to our Mil-Spec Type III anodized coating. The factory drum is made of 333 Cast aluminum. 333 has a shear strength of 17,300PSI. Our drum is made of 7075-T6 which has a shear strength of 48,000PSI. While this drum is nowhere near as strong as our billet 4140HTSR version which has a shear strength of 167,000PSI it still will give enough increase in strength for most street cars. We DO NOT recommend the aluminum drum for drag cars or cars that produce over 1000HP as it will fail at this power level. Any vehicles producing more than 1000HP please purchase our steel version!
The RevMax Patent Pending E clutch hub assembly fixes all of these issues and also improves rigidity and overall holding capacity. Our design has a shoulder that extends all the way out to the edge of the steel pressure plate to support it. The factory design has tremendous flexing due to the absence of any support area for the pressure plate to rest against. Additionally, we offer billet apply pistons as an upgrade for the 8HP45, 845RE, 870RE, 8HP70, and 8HP75. These pistons feature a full contact area for the apply to contact resulting in cleaner engagement, less deflection, and increased holding capacity. Buy upgrading to the billet piston design allows for the use yet another additional friction and therefore increasing holding capacity even more.
Last, the RevMax design allows for the use of one additional friction on all applications. All of the hubs come with custom Kolene steels. These steels are to be used with factory thickness clutches and will enable the builder to add capacity to the drum.