RENN HAUS specializes in upgrading and reinforcing the five forward clutches in the Mercedes 722.6 automatic for the high horsepower gains of highly tuned engines. The 722.6 automatic is used in many Mercedes Benz as well as the Porsche 996/997 Twin Turbo and the Chrysler SRT8 products such as the Grand Cherokee, Challenger, Charger, 300 and Viper SRT10. Our performance technicians can also build a transmission manual or automatic to suit your needs. We can install everything from just and upgraded high strength clutch to a sequential gearbox in your vehicle.  Our technicians have decades of experience in performance applications.  An untrained person trying to take apart a gearbox is simply trying to get it apart without breaking or damaging the parts. Often they do not accomplish this. Conversely, the experienced technician carefully and purposely removes parts of the gearbox in a sequenced order to determine its condition.

During the disassembly, process measurements are made to determine the condition and setup of the gearbox. Certain key measurements include the ring and pinion R setting, differential bearing preload and backlash, and shift fork position. Checking these measurements is essential in determining if the gearbox has been serviced improperly during prior work or if certain components have become worn and are no longer within specification. Further disassembly allows the technician to examine parts for wear and to check the fit and finish of mating parts. During this stage the technician is looking to accomplish several things; sort out damaged or worn parts, verify and diagnose the customer complaint or gearbox problem, and begin to compile a list of parts needed for repair.
The next stage of the rebuilding process is cleaning. During this stage, all oil, grit, and foreign matter are removed from the individual Parts. This process allows the technician to double check that nothing has been missed during disassembly. Examples of problems found during cleaning include cracks in cases or gears, surface wear on bearing races, gears, shafts, and other parts.

The machining and blueprinting process is used to correct permissible tolerance variations with individual parts or to enhance the function of the part. Often machining cannot repair a part and replacement is required. However, some parts can be machined to function properly without replacement. Examples of this include: surface grinding of spacers and shims for setup, straightening bent shafts, or milling warped surfaces flat. The primary benefit of being able to able to machine and blueprint parts is that very precise setup is possible. The tolerance of the re-machined part will be much tighter than that of the original. A good example of this is the process of surface grinding spacers. The factory spacers are turned (lathe cut) and hardened; grinding the mating surfaces results in parallel and flat surfaces to within .0001/inch which is far better than factory.

The reassembly process is the final stage before the gearbox is reinstalled into the vehicle. At this time final fit and finish of each part is checked. The parts are usually put together in stages and individual subsystems are checked for perfect functionality. For example, the shift rails are assembled and detents are checked before reinstalling a case section or housing. Also, all tolerances and specifications are checked and the bolts are tightened to the correct torque.

Please call to discuss your needs in detail.