Beginning with the 1996 model year, all of the 42RE and 47RE models with electronically controlled governor pressure were produced with an added No. 10 checkball in the transfer plate, as shown in Figure 1.
To ensure sequential downshifts.
(1) Transfer Plate – Changes in the lower-side casting to accommodate the added No. 10 check-ball (illustrated in Figure 1), and the transfer-plate upper side, illustrated in Figure 2, where the No. 9 checkball is not used in the 47RE.
(2) Overdrive Spacer Plate – Changes in the hole configuration to accommodate the added No. 10 checkball, as illustrated in Figure 3.
Figure 4 illustrates the main spacer plate.
(3) Overdrive Valve Body – Casting changes to accommodate the added No. 10 checkball, as illustrated in Figure 5.
None of the individual parts listed will inter-change with previous-design-level parts. A complete service package will back-service any 42RE or 47RE.
Figure 6 shows the checkball locations in the main valve body.
Figure 7 describes each checkball and its function.
No 3-4 shift before and after rebuild.
A bad VSS, TPS, ECT, OD-cancel switch, solenoid and/or solenoid gasket, ignition switch or park/neutral switch is the primary cause of no 3-4 shift or TCC apply. But in many instances, early-model trucks have been equipped with an incorrect SMEC (single-module engine controller) at the factory (See Figure 8). Vehicle owners may be unaware that there was no 3-4 shift. After overhaul, the technician struggles to correct this condition. At some point the computer is determined to be defective. When a new computer is installed, it also may not be the right one.
The confusion is that Ram vans, wagons, pickups and Ram Chargers could have a 3-speed transmission (904, 999 or 727) or might be equipped with a 4-speed (A500 or 518). When ordering a computer for a vehicle with a 4-speed transmission, you must specify that it is a 4-speed unit. Do not rely on engine size alone. A 1989 5.2-liter pickup with a 3-speed would have an SMEC part number of 4379887, but the same vehicle equipped with a 4-speed would use part number 4379889.
Install the correct computer.
Beginning at the start of production for the 1997 model year, all 4L80-E/4L80-EHD transmissions were produced with a center lube, in addition to front and rear lube. This bulletin covers some of the changes that occurred in the center-gearbox area.
To provide a more-desirable distribution of lube flow to the center of the transmission.
(1) Sun-Gear Shaft – Has revised bushing journals, as shown in Figure 9, to accommodate the new center support and must be used with the new center support.
(2) Sun Gear – Has larger lubrication passages on the inside splines of the sun gear, and the new design has a smaller hole between the gears, as shown in Figure 10.
(3) Rear Ring-Gear Shaft – The lube holes that were cross-drilled in the previous shaft, and the lube passage through the center, have been eliminated in the new-design shaft, as shown in Figure 11.
(4) Rear Internal Ring Gear – New design level has lube passages cut through the area where the shaft splines into the ring gear, and cut into the bearing race that goes on the internal ring gear in this location, as shown in Figure 12.
(5) Output Shaft – New design has eliminated the lube hole that was present in the previous models, as shown in Figure 13.
None of the parts listed will interchange with any of the previous-design-level parts, and none of the previous-design-level parts can be used in the units with center lube.
July 2000 Issue
Volume 17, No. 7
- Chrysler 42RE and 47RE: Checkball Locations and Functions; New Checkball Added in Transfer Plate
- A500/A518: No Overdrive
- THM 4L80-E/4L80-EHD: Center-Gearbox Differences On Center-Lube Transmissions