Hydraulic System

Hydraulic System

Fluid Pump
This transmission has a gear-type pump that supplies fluid under pressure to the hydraulic system.

The torque converter impeller hub rotates the drive gear of the pump.

Filter
Fluid is drawn from the transmission pan by the pump through the filter. The filter and its accompanying seal are part of the fluid path from the sump (pan) to the pump.

Remote Fluid Filter - Early Build Vehicles:

This transmission is equipped with a remote filter transmission fluid filter. Most of the transmission fluid which leaves the front fluid cooler tube connector passes through the remote filter and is directed into the cooling circuit. The remote filter manifold, by-passes the filter element and takes 10 percent of the incoming hot fluid and directs it through a small orifice and into a serviceable filter element. The filtered transmission fluid is then directed back into the rear lubrication circuit through the larger opening in the remote filter manifold.

Late Build Vehicles:

Late build vehicles do not have the remote filter mounted on the passenger side frame rails. The remote filter and the previous design sump filter are both replaced by a high efficiency sump filter (HESF). The HESF is designed to trap smaller contaminants to help prevent solenoid sticking issues. Because the HESF is wider and taller, a new design bottom pan must be used with it as a set. The HESF requires replacement less often (60K intervals) than the remote filter element and only the automatic transmission fluid (ATF) lost when installing a new design sump filter must be replaced.