A/T - Circuit Leaks, Low/Reverse Accumulator Cover
TECHNICAL BULLETIN # 231DATE: 1994
TRANSMISSION: 41TE (A-604)
SUBJECT:
Circuit leaks, low/reverse accumulator cover assembly
APPLICATION: Chrysler, Plymouth
Low/reverse clutch circuit leaks can cause several types of operational problems, such as:
^ Coasting 2-1 downshift clunks or chatters.
^ Delayed forward and reverse engagements.
^ Chatter or slipping in first and reverse gears under load.
^ False Trouble Code 24; Low/Rev. Pressure Switch.
^ Repeat Fail-safe Mode. Trouble Code 39, (89-90) or Codes 50 or 51 (91 & up).
To avoid leak problems after a rebuild, pay close attention to the following three areas of the low/reverse circuit.
(Step 1):
Make sure that the orifice/screen assembly is in place in the low/rev. piston (figure 1). It has been known to blow out resulting in a 1/8" hole in the piston, rather than a .020" orifice.
(Step 2):
The low/rev. piston housing (figure 2), is a stamped steel dish fastened to the back of the case with three little screws. A gasket between the piston housing and the case is used to seal the apply oil route through the piston (figure 3). Normal forces tend to distort the housing by "bending out" the screw holes toward the gasket. This can result in a leak. It's a good idea to get a new housing during overhaul. If you reuse the old one, make sure you lay the housing face down on a hard, flat surface and tap the holes flat again (figure 4).
Lay the low/reverse housing on top of an AOD intermediate roller clutch race. The race is used to support the screw holes.
You can increase the gasket clamping force over the housing apply hole by laying the housing face up on a rag on your bench. Hold a 7/16" deep socket directly over the apply hole and smack it a couple of times with a hammer (figure 5).
(Step 3):
The low/rev. accumulator cover has an "O"-ring in it's groove. This groove is closer to one side of the cover than the other (figure 6). If the cover is installed into the case upside down, the "O"-ring will not go down far enough into its case bore to be supported correctly. The "O"-ring blows itself out of its groove in bits and pieces, creating a substantial leak in the apply circuit.
The cover should be installed with the three bumps facing the accumulator and the single bump facing the snap-ring (figure 7).