Chrysler Full-Size Vans 1967-1988 Repair Guide

New Process A-745 3-Speed Overhaul

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The Dodge A-745 is a three-speed synchromesh transmission having helical type gears. Lubricant capacity is 3 1 / 4 pints.

DISASSEMBLY



See Figure 1

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Fig. Fig. 1: Exploded view of the New Process A-745 manual transmission

  1. Remove output flange nut, then the drum and flange assembly, if so equipped. Remove parking brake assembly, if so equipped.
  2.  
  3. Remove case cover. Measure synchronizer float with a feeler gauge between the end of a synchronizer pin and the opposite synchronizer outer ring. A measurement from 0.050-0.090" is acceptable for 1964-67 models. The measurement should be 0.060-0.117" for 1968 and up models.
  4.  
  5. Remove the extension housing from the case.
  6.  
  7. Remove the mainshaft rear bearing, if it did not come off with the extension housing.
  8.  
  9. Remove transmission case cover and gasket.
  10.  
  11. Remove the drive pinion bearing retainer.
  12.  
  13. When removing the drive pinion and bearing assembly from the transmission case, slide the front inner stop ring from the short splines on the pinion as the assembly is being removed from the case.
  14.  
  15. Remove the main drive pinion bearing snapring.
  16.  
  17. Press bearing off pinion shaft and remove oil slinger.
  18.  
  19. Remove the mainshaft pilot bearing snapring from the cavity of the pinion gear.
  20.  
  21. Remove the 15 pilot roller bearings.
  22.  
  23. Remove seal from pinion retainer.
  24.  
  25. Remove mainshaft rear bearing snapring from groove in mainshaft rear bearing bore in the case.
  26.  
  27. Remove the rear bearing snapring from groove in mainshaft rear bearing bore in the case.
  28.  
  29. Remove synchronizer assembly from the case.
  30.  
  31. Remove second and third-speed shift fork.
  32.  
  33. Remove synchronizer clutch gear, snapring, clutch gear, second-speed gear, and first and reverse sliding gear from the mainshaft.
  34.  
  35. Withdraw mainshaft and bearing out through rear of the case.
  36.  
  37. Remove the synchronizer clutch gear, second-speed gear, low and reverse sliding gear, and low and reverse shift fork from the case.
  38.  
  39. With a dummy shaft, drive the countershaft toward the rear of the case until the small key can be removed from the countershaft.
  40.  
  41. Remove the countershaft from the case.
  42.  
  43. Lift the cluster gear, the thrust washers and the dummy shaft assembly out of the case.
  44.  
  45. Dismantle the cluster gear, (88 rollers, four spacer rings and the center spacer from the cluster).
  46.  
  47. With a blunt drift, drive the reverse idler shaft toward the rear of the case far enough to remove the key from the shaft.
  48.  
  49. Completely remove the shaft from the case, then remove the idler gear.
  50.  
  51. Remove the thrust washers and 22 rollers.
  52.  
  53. With a small punch, remove low and reverse gear lever shaft tapered lock pin by driving it toward the top of the transmission case.
  54.  
  55. Remove the second and third gear lever shaft in the same manner.
  56.  
  57. Remove the lever shafts from the transmission case being careful not to lose the spring-loaded detent balls.
  58.  
  59. Remove the interlock sleeve, spring pin and detent balls.
  60.  
  61. Remove both lever shaft seals and discard same.
  62.  

ASSEMBLY



  1. Place oil slinger on the main drive pinion with the offset outer portion next to the drive pinion teeth.
  2.  
  3. Place the main drive pinion bearing on the pinion shaft with the outer snapring away from the pinion gear.
  4.  
  5. Press the bearing into position so it is seated firmly against the oil slinger and pinion gear.
  6.  
  7. Install the bearing retaining snapring in its groove on the pinion shaft.
  8.  
  9. Heavily grease the 15 pilot bearing rollers and install them in the cavity at the rear of the main pilot drive.
  10.  
  11. Install the snapring.
  12.  
  13. Place the bearing spacer in the center of the bore in the cluster gear and use the dummy shaft to assist in assembling the roller bearings.
  14.  
  15. Install a row of 22 rollers next to one end of the spacer, using heavy grease to hold them.
  16.  
  17. Place one of the four bearing spacer rings next to the row of the rollers, and install another row of 22 rollers next to the spacer ring.
  18.  
  19. Install another spacer ring at the outside end of the second row of bearing rollers.
  20.  
  21. At the opposite end of the cluster gear bore, install the remaining spacer rings and bearing rollers in the same sequence as listed in Steps 8, 9, and 10.
  22.  
  23. With a small amount of grease, install the front thrust washer on the dummy shaft at the front end of the cluster gear, with the tabs outward.
  24.  
  25. Install the tabbed rear thrust washer onto the dummy shaft against the rear of the cluster gear with the tabs inserted in the cluster gear grooves.
  26.  
  27. Install the remaining rear thrust washer plate onto the rear of the gear and dummy shaft with the step in the washer facing upward, as viewed from the rear.
  28.  
  29. Align tabs of the front thrust washer vertically to index the notches in the transmission case.
  30.  
  31. Using the countershaft, drive the dummy shaft forward, out of the case. Countershaft end-play should be 0.0045-0.028".
  32.  
  33. Position a dummy shaft in the reverse idler gear and, using heavy grease, install the 22 roller bearings into the gear.
  34.  
  35. Place the thrust washers at each end of the reverse idler gear, then place the assembly in the case with the chamfered end of the gear teeth toward the front.
  36.  
  37. Insert the reverse idler shaft into the rear case bore with the keyway to the rear, pushing the dummy shaft toward and out of the front of the transmission.
  38.  
  39. With the keyway in proper alignment, insert the key and continue driving the shaft forward until the key seats in the recess.
  40.  
  41. Install two new lever shaft seals in the transmission case.
  42.  
  43. Lubricate and install second and third-speed lever shaft in the bores of the case.
  44.  
  45. Install the second and third speed lever shaft lock pin in the hole in the case.
  46.  
  47. Place interlock parts in the case in the following order: ball, sleeve, spring, pin and ball.
  48.  
  49. Enter low and reverse lever shaft in the case bore, depress the detent ball against spring tension and push the lever shaft firmly into position, in order to prevent the ball from escaping.
  50.  
  51. Install low and reverse lever shaft lock pin in the case.
  52.  
  53. Place low and reverse fork in the lever shaft, with the offset facing the rear.
  54.  
  55. While holding the low and reverse sliding gear in position in the fork, with the hub extension to the rear, insert the mainshaft with the rear bearing through the rear of the case and into the sliding gear.
  56.  
  57. Place synchronizer stop ring spring, then the rear stop ring, on the synchronizer splines of the second-speed gear. Install the second-speed gear onto the mainshaft. Synchronizer shims must be added if synchronizer float is more than the maximum in Step 2, disassembly. If float was less than minimum, the six pins must be shortened.
  58.  
  59. Install the synchronizer clutch to shoulder to the front.
  60.  
  61. Select the thickest synchronizer clutch gear snapring that can be used, and install it in the mainshaft groove.
  62.  
  63. Check to see that clearance between clutch gear and second-speed gear is 0.004-0.014".
  64.  
  65. Hold the synchronizer clutch gear sleeve and two outer rings together with pins properly entered into the holes in the clutch gear sleeve and with the clutch gear sleeve engaged in the groove of the second- and third-speed shift fork, position the fork in the second- and third-speed lever shaft.
  66.  
  67. While holding the synchronizer parts and fork in position, slide the mainshaft forward, entering the synchronizer clutch gear into the clutch gear sleeve and simultaneously entering the mainshaft rear bearing in the case bore.
  68.  
  69. While still holding the synchronizer parts in position, tap the mainshaft forward until the rear bearing bottoms in the case bore.
  70.  
  71. Install the mainshaft rear bearing snapring into place in the case bore.
  72.  
  73. Install a new drive pinion retainer seal.
  74.  
  75. Place the synchronizer front inner ring in position in the front outer ring, and enter the main drive pinion through the case bore.
  76.  
  77. Engage the splines on the rear of the pinion with the inner stop ring, and tap the drive pinion into the case until the outer snapring on the pinion bearing is against the transmission case.
  78.  
  79. Place the drive pinion bearing retainer over the pinion shaft and against the transmission case. While holding the retainer against the transmission case, measure the clearance between the retainer and case and choose a gasket 0.003-0.005" thicker than this reading.
  80.  
  81. Torque the front bearing retainer bolts to 30 ft. lbs.
  82.  
  83. Install a new extension housing seal.
  84.  
  85. Install extension housing and torque the bolts to 50 ft. lbs.
  86.  
  87. Install the parking brake assembly, on vehicles so equipped.
  88.  
  89. Install the parking brake drum (if so equipped) and flange assembly and torque to 175 ft. lbs.
  90.  
  91. Install the drain plug in the transmission case.
  92.  
  93. Install the gearshift operating levers, and torque to 12 ft. lbs.
  94.  
  95. Install the back-up light switch.
  96.  
  97. Install the speedometer cable and drive gear. Bring transmission to lubricant level.
  98.  

 
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