Loadflite/Torqueflite A727, A904-LA, A904T, A998, A999

Fig. 1 Loadflite 727 automatic transmission less lock-up torque converter:

Fig. 2 Loadflite 727 automatic transmission w/lock-up torque converter:

Fig. 3 Loadflite A-904T, A-998 & A-999 automatic transmission w/lock-up torque converter:

Fig. 4 Clutch, band & gear system:

These transmissions, Figs. 1 through 3 combine a torque converter with a fully automatic three speed gear system. The converter housing and transmission case are an integral aluminum casting. The A-998 and A-999 transmission is similar in appearance and operation to the A-904 transmission. The service procedures for both transmissions are the same as the A-904 transmission. The transmission consists of two multiple disc clutches, an overrunning (one-way) clutch, two servos and bands and two planetary gear sets to provide three forward speeds and reverse, Fig. 4.
The common sun gear of the planetary gear sets is connected to the front clutch by a driving shell that is splined to the sun gear and to the front clutch retainer.

Fig. 5 Wide ratio planetary gear set used on A-904T, A-998 & A-999 transmissions:

All A-904T, A-998 and A-999 transmissions, Fig. 5, are equipped with a wide ratio gear set. Low gear ratio is 2.74 to 1. The sun gear and front planetary gear set is unique to the wide ratio transmission.
The hydraulic system consists of a single oil pump and a valve body that contains all the valves except the governor valve.
Venting of the transmission is accomplished by a drilled passage through the upper part of the front pump housing.
The torque converter is attached to the engine crankshaft through a flexible driving plate. The converter is cooled by circulating the transmission fluid through an oil-to-water type cooler located in the radiator lower tank. The converter is a sealed assembly that cannot be disassembled.

Fig. 6 Lock-up torque converter operation:

A lock-up clutch (torque converter clutch) is incorporated in some transmission applications, Fig. 6.
The lock-up mode is activated only in direct drive above a minimum preset vehicle speed. At wider throttle openings, where the 2-3 upshift occurs above the minimum lock-up speed, the lock-up shift will occur immediately after the 2-3 upshift.