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TSB 21-11-97 Rev.A

Reverse Buzz (46RE)

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Date: Sep 5, 1997
This is a revised TSB which supersedes a previous TSB.

Models 1996-97 BR (Ram) with automatics

Symptom: A buzz (some call it a moan) sound when shifting into reverse.  This condition may be more noticeable on a cold vehicle that has been parked outside overnight.

Diagnosis: Start with a cold vehicle (parked outside overnight), start the engine and shift from park to reverse and from drive to reverse several times while listening for a buzz sound in reverse.  The buzz may be more noticeable with the windows down or from outside the cab.  If the buzz is heard in reverse, perform the repair procedure.


(point of information - CC now has regular 7176 ATF, called CC ATF, and ATF+2, and ATF+3.  The feeling is that eventually all will be ATF+3 which is probably 100% synthetic and OK for all CC automatics.)

Procedure: involves removing the OD unit, prop shaft(s) and transfer case if necessary, replacing the rear band adjusting lever, reaction lever and strut with high ratio components along with replacement of the regulator valve pressure plug and sleeve.


  1. Shift the transmission into park and the transfer case into neutral.
  2. Disconnect the negative battery cable(s).
  3. Raise the vehicle on a hoist.
  4. Remove the transfer case skid pad if so equipped.
  5. Mark the front and rear propeller shafts and U-joints for alignment reference and remove the shafts.
  6. Disconnect the wires at the vehicle speed sensor.
  7. Disconnect the vent hose and vacuum harness at the transfer case switch.
  8. Disconnect the shift rod from the grommet in the transfer case shift lever, or from floor shift arm - whichever has easier access.
  9. Support the transmission on a jack stand.
  10. Remove the rear cross member.
  11. Support the transfer case with a jack stand and secure the T-case to the stand with safety chains.
  12. Remove the nuts attaching the T-case to the transmission.
  13. Move the T-case rearward until it is free of the transmission output shaft.
  14. Lower the jack and move the T-case from under the vehicle.
  1. Remove the gear shift and throttle levers from shaft of valve body.
  2. Disconnect wires at solenoid case connector.
  3. Position a drain pan under the transmission.
  4. Loosen the transmission oil pan bolts and allow the transmission fluid to drain into the drain pan.
  5. While supporting the oil pan, remove the bolts an lower the pan from the transmission. Dump the remaining fluid into the drain pan.
  6. Remove the fluid filter from the valve body.
  7. Remove the valve body to transmission case bolts.
  8. Lower the valve body enough to remove accumulator piston and springs.
  9. Work manual lever shaft and electrical connector out of the transmission case.
  10. Lower valve body, rotate valve body away from case, pull park rod out of sprag, and remove valve body.
  1. Remove the bolts attaching the OD unit to the transmission.
  2. Carefully slide the OD unit off the intermediate shaft. Do not tilt unit during removal. Keep OD unit as level as possible.
  3. Insert alignment tool 6227-2 into the splines of the planetary gear on overrunning clutch to prevent the splines from rotation out of alignment.
  4. Remove and retain the overdrive piston thrust bearing and spacer.
  1. Loosen the locknut and unscrew the reverse band adjusting screw (but do not remove the screw).
  2. Using a small punch and hammer, tap the reverse band reaction pin out from the front until it can be removed. Remove the shaft so both levers can be removed (Fig 1). Discard the removed levers and strut.
  3. Inspect the shaft "O" rings and replace them if necessary P/N 06030910.
  4. Compress the rear servo piston enough to permit snap ring removal.
  5. Remove the servo piston snap ring. Use caution when removing to prevent servo bore scratching.
  6. Remove the rear servo retainer, spring, and piston assembly (Fig 2).
  7. Measure the distance from the end of the rear servo piston plug to the face of the piston (Fig 3). Record this measurement for future use when adjusting the rear band.
  8. Reinstall the rear servo retainer, spring, and piston into the transmission. Secure it with a snap ring.
  9. Install the band adjusting screw (from old lever) and partially install the new band adjusting lever by pushing the reaction shaft through one flange of the lever P/N 04897877AA.
  10. Using petroleum jelly, assemble the replacement strut and reaction lever P/N 04897877AA.
  11. Install the assembled strut and reaction lever inside the adjusting lever and push the reaction pin completely through the assembly until it is flush with the back of the transmission case.
  1. Inspect the gasket to ensure it was not damaged during removal. If damaged, refer to the service manual for replacement.
  2. Install the thrust bearing and spacer in overdrive unit sliding hub. Use petroleum jelly to keep it in place.
  3. Carefully slide the alignment tool 6227-2 out of the unit.
  4. Raise the overdrive unit and carefully slide it straight onto the intermediate shaft.
  5. Install the attaching bolts and tighten them to 25 ft-lbs (34 Nm) in a diagonal pattern.
  6. Install transmission mount and tighten to 30 ft-lbs (41 NM)
  7. Connect speed sensors and speedometer wires.
  1. Remove the plug in the rear servo test port.
  2. Based on the measurement taken in step 7 of REVERSE BAND LEVERS AND STRUT REPLACEMENT select the appropriate size drill bit from the following table:
  3. Insert the butt end of the appropriate drill into the test port 3" deep and centered beneath the servo plug.
  4. With the bit properly located, tighten the reverse band adjusting screw to 72 in-lbs (8 Nm) and back off the screw 2 1/4 turns.
  5. Loosen the adjusting screw and repeat step 4. While holding the adjusting screw, tighten the adj screw lock nut to 25 in-lbs (34 Nm).
  6. Remove the drill bit and replace the rear servo test port plug.
  1. Without disassembling the valve body, remove the regulator valve cover hiding the pressure plug and sleeve (Fig 4).
  2. Remove the existing pressure plug and sleeve and discard the old parts. Install the replacement parts from the kit.
  3. Reinstall the regulator valve cover and tighten the screws.
  1. Place valve body manual lever in low (1 position) so ball on rod will be easier to install in sprag.
  2. Position valve body in case and work end of park lock rod into and through pawl sprag. Move rod to check engagement.
  3. Install accumulator piston and springs. The inner spring has a smaller diameter.
  4. Swing valve body over piston and outer spring to hold it in place. Align accumulator piston and outer spring, manual lever shaft, and electrical connector in case.
  5. Seat valve body in case and install the bolts. Alternately tighten each bolt to 100 in-lbs (11 Nm).
  6. Install the fluid filter. Replace as necessary (ALWAYS -Dave) with P/N 03515996.
  7. Install throttle and gearshift levers on valve body manual shaft.
  8. Check and adjust front band.
  9. Connect solenoid case connector wires.
  10. Install the transmission oil pan with a new gasket P/N 02464324. Tighten the pan bolts to 13 ft-lbs (17 Nm).
  11. If applicable, mount the transfer case on a jack and secure the case with chains.
  12. Align transfer case and transmission shaft and install transfer case on transmission. Tighten transfer case bolts to 26 ft-lbs (35 Nm).
  13. Connect the vent hose.
  14. Connect indicator switch harness to transfer case if necessary. Secure wire harness to clips on transfer case.
  15. Align and connect propeller shafts. Tighten attaching bolts to 170 in-lbs (19 Nm).
  16. Lower the vehicle.
  17. Fill transmission with mopar ATF +2, type 176 fluid P/N 04798233.
  18. Reconnect negative battery cable and reset radio and clock.
  19. Adjust gearshift linkage and throttle valve cable if necessary.
Time allowance: 2.7 hr, add 1.7 hr for 4X4

Thanks to Bob Bergevin and Barry Drodge for supplying this TSB information

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This page was edited on: May 3, 2004