Mazda Trucks 1972-1986 Repair Guide

Adjustments

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KICKDOWN SWITCH



See Figures 1, 2 and 3

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Fig. Fig. 1: Kickdown and downshift adjustment for the R3A automatic transmission



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Fig. Fig. 2: Kickdown switch check for the 3N71B automatic transmission



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Fig. Fig. 3: Downshift solenoid test for the 3N71B transmission

  1. Make sure that the accelerator pedal travels its entire stroke properly.
  2.  
  3. Turn the ignition switch to ON, but don't start the truck.
  4.  
  5. Depress the accelerator pedal as far as possible. As the throttle nears the wide open position, the contact point of the kickdown switch should close with a light click from the solenoid. The kickdown switch should begin operation at about 7 / 8 of full pedal stroke.
  6.  
  7. If not, loosen the kickdown switch attaching nut and adjust the switch.
  8.  
  9. Tighten the attaching nut when adjustment is correct.
  10.  
  11. If the switch cannot be made to operate properly, replace it.
  12.  

SHIFT LINKAGE R3A



See Figure 4

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Fig. Fig. 4: View of the manual linkage on the R3A transmissionarrow shows adjustment point

  1. Put the shift lever in NEUTRAL.
  2.  
  3. Raise and support the truck on jackstands.
  4.  
  5. Adjust the position of the manual lever by turning the T-joint so that the manual lever is in NEUTRAL.
  6.  
  7. Shift the gearshift lever to PARK and make sure that the parking pawl is engaged and there is no looseness in the linkage.
  8.  
  9. Lower the truck and check transmission operation.
  10.  

3N71B See Figures 5 and 6

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Fig. Fig. 5: Exploded view of the 3N71B transmission mounting



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Fig. Fig. 6: View of the 3N71B manual linkage adjustment points

  1. Put the gearshift lever in Neutral.
  2.  
  3. Raise and support the truck.
  4.  
  5. Disconnect the T-joint from the lower end of the selector lever operating arm.
  6.  
  7. Move the transmission manual lever to Neutral, the 3rd detent position from the rear of the transmission.
  8.  
  9. Loosen the two T-joint retaining nuts and adjust the T-joint so that it freely enters the hole of the lever. Tighten the retaining nuts to secure the adjustment.
  10.  
  11. Connect the T-joint to the lever and attach it with the spring washer, flat washer and retaining clip.
  12.  
  13. Lower the truck and check the operation of the linkage. Be sure that all gears engage properly.
  14.  

SHIFT LEVER HANDLE INTERLOCK3N71B



See Figures 7 and 8

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Fig. Fig. 7: View of the shift handle for the 3N71B transmission



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Fig. Fig. 8: 3N71B shifter performance chart

The interlock should be adjusted when it does not perform as shown in the accompanying illustration, or, whenever the handle has been removed.

  1. Back off the locknut below the handle.
  2.  
  3. Position the shifter in either N or D.
  4.  
  5. Screw in the handle until no play is felt at the interlock button.
  6.  
  7. Turn the handle one additional turn, if necessary, to position the button on the driver's side.
  8.  
  9. Depress the button and shift to P. If the lever cannot be moved to the P position, screw in the handle an additional turn, repeating the shift move and additional turn, until P can be engaged smoothly. From this point, shift through the various positions, confirming that the shifter works as shown in the illustration. If the lever can be shifted to R from either P or N, or into 2 from D, without depressing the button, back out on the handle.
  10.  
  11. When the adjustment is completed, check that the button protrudes 6.0mm (0.236 in.) from the handle in the N or P position. Recheck the shift pattern.
  12.  
  13. Tighten the locknut to 15 ft. lbs.
  14.  

NEUTRAL SAFETY/BACK-UP LIGHT SWITCHR3A



See Figure 9

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Fig. Fig. 9: Neutral safety/back-up light switch adjustment on the R3A transmission

The switch is located at the base of the shift lever.

  1. Remove the housing from the shift lever.
  2.  
  3. Adjust the shift lever so that there is 0-0.3mm (0-0.0118 in.) clearance between the pin and guide plate when the lever is in NEUTRAL.
  4.  
  5. Loosen the retaining screws and adjust the neutral safety switch so that the pin hole in the switch aligns with the pin hole in the sliding plate with the lever in NEUTRAL.
  6.  
  7. At this point, the engine should start only in PARK or NEUTRAL, and the back-up lights should come on only in REVERSE.
  8.  
  9. If the switch is defective, replace it by removing the retaining screws and disconnecting the wiring.
  10.  

3N71B See Figure 10

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Fig. Fig. 10: Neutral safety/back-up light switch adjustment on the 3N71B transmission

The switch is located on the right side of the transmission case.

  1. Adjust the shift linkage.
  2.  
  3. Place the transmission shift rod in Neutral (3rd detent from the rear of the transmission).
  4.  
  5. Remove the transmission shift rod retaining nut and disconnect the rod from the switch.
  6.  
  7. Loosen the switch attaching bolts. Remove the screw from the alignment pin hole at the bottom of the switch.
  8.  
  9. Rotate the switch and insert an alignment pin, 1.5mm (0.059 in.) diameter into the alignment pin hole and internal rotor.
  10.  
  11. Tighten the two switch attaching bolts and remove the alignment pin.
  12.  
  13. Reinstall the alignment pin hole screw in the switch body.
  14.  
  15. Connect the shift rod.
  16.  
  17. Check the operation of the switch. The engine should start, only with the transmission selector lever in Neutral or Park. The back-up lights should come on, only with the lever in Reverse.
  18.  
  19. If the switch is defective, replace it by simply removing the attaching screws and disconnecting the wiring.
  20.  

INTERMEDIATE BANDR3A and 3N71B



See Figures 11 and 12

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Fig. Fig. 11: Intermediate band adjustment points on the R3A transmission



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Fig. Fig. 12: Intermediate band adjustment points on the 3N71B transmission

  1. Raise and support the truck.
  2.  
  3. Place a drain pan under the transmission and loosen the pan attaching bolts to drain the fluid. Finally remove all the bolts except the two at the front.
  4.  
  5. When the fluid has drained, remove and thoroughly clean the pan.
  6.  
  7. Discard the pan gasket.
  8.  
  9. Loosen the brake band adjusting screw locknut and tighten the adjusting screw to 9-11 ft. lbs.
  10.  
  11. Back the adjusting screw off two turns.
  12.  
  13. Hold the adjusting screw locknut to 22-29 ft. lbs.
  14.  
  15. Install a new pan gasket and install the pan on the transmission.
  16.  
  17. Lower the truck and fill the transmission with fluid.
  18.  

 
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