Читать книгу Ford Differentials - Joseph Palazzolo - Страница 24

Hi9 has developed an actual 9-inch gear arrangement, also called TrueHi9. Again, the pinion located above center helps with driveshaft angles and ground clearance, but it requires unique oil porting and baffling in order to catch and feed oil to the pinion bearings. This arrangement uses a unique 9-inch-style gear set, produced by Richmond Gear, that has the reverse-cut method to drive on the drive side of the gear tooth faces.

Hi9 also offers the MegaHi9. It uses gears that are made out of the stronger SAE9310 material (as compared to SAE 8620), along with a 35-tooth splined pinion arrangement. The material change makes the gears approximately 15 percent stronger.

The TrueHi9 design has a distinctive thrust button feature to help combat ring gear separating forces along with a unique reinforced gear case in the pinion pocket bearing area. This thrust button is just a hardened, threaded, adjustable support that is very close to the ring gear back face. When the ring gear deflects from high-torque loads, the thrust button surface actually contacts a specially machined surface on the back face of the ring gear and resists that deflection.

Here is a comparison of pinions from a 10-inch ring and pinion set with a 35-tooth spline (left) and a stock 9-inch pinion with a 28-tooth spline (right).

Both the TrueHi9 and the MegaHi9 units use the 9-inch-style differential, which means that all aftermarket differential options can be used in these axle housings. These axles are common upgrades for Jeep Wranglers and Ford Broncos.