Chevrolet Chevette/1000 1976-1988 Repair Guide

Transmission

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REMOVAL & INSTALLATION



Gasoline Engine


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Fig. Fig. 1Cross-sectional view of the 4-speed manual transmission

  1. Remove the shift lever as outlined in this section.
  2.  
  3. Raise and safely support the vehicle and drain the lubricant from the transmission.
  4.  
  5. Remove the driveshaft as described in .
  6.  
  7. Disconnect the speedometer cable and back-up light switch.
  8.  
  9. Disconnect the return spring and clutch cable at the clutch release fork.
  10.  
  11. Remove the crossmember-to-transmission mount bolts.
  12.  
  13. Remove the exhaust manifold nuts and converter-to-tailpipe bolts and nuts. Remove the converter-to-transmission bracket bolts and remove the converter.
  14.  
  15. Remove the crossmember-to-frame bolts and remove the crossmember.
  16.  
  17. Remove the dust cover.
  18.  
  19. Remove the clutch housing-to-engine retaining bolts, slide the transmission and clutch housing to the rear, and remove the transmission.
  20.  

To install:

  1. Place the transmission in gear, position the transmission and clutch housing, and slide forward. Turn the output shaft to align the input shaft splines with the clutch hub.
  2.  
  3. Install the clutch housing retaining bolts and lockwashers. Tighten the bolts to 25 ft. lbs.
  4.  
  5. Install the dust cover.
  6.  
  7. Position the crossmember to the frame and loosely install the retaining bolts. Install the crossmember-to-transmission mounting bolts. Tighten the center nuts to 33 ft. lbs.; the end nuts to 21 ft. lbs. Tighten the crossmember-to-frame bolts to 40 ft. lbs.
  8.  
  9. Install the exhaust pipe to the manifold and the converter bracket on the transmission. Tighten the converter bracket rear support nuts to 150 in. lbs.
  10.  
  11. Connect the clutch cable. Perform Initial Ball Stud Adjustment and Clutch Cable Attachment and Adjustment. Also, adjust clutch pedal free-play, if necessary.
  12.  
  13. Connect the speedometer cable and backup light switch.
  14.  
  15. Install the driveshaft.
  16.  
  17. Fill the transmission to the correct level. Please refer to under Fluids And Lubricants and the Capacities Chart for the correct type and quantity of lubricant. Lower the car.
  18.  
  19. Install the shift lever and check operation of the transmission.
  20.  

Diesel Engine


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Fig. Fig. 2Cut-away view of the 5-speed manual transmission-diesel engines

  1. Disconnect the negative battery cable.
  2.  
  3. Unscrew the retaining screws and then remove the shift lever console.
  4.  
  5. Remove the mounting screws and remove the shift lever assembly.
  6.  
  7. Unscrew and remove the upper starter mounting bolts.
  8.  
  9. Raise the front of the car and drain the lubricant from the transmission.
  10.  
  11. Remove the driveshaft as detailed in .
  12.  
  13. Disconnect the speedometer and the backup light switch wires.
  14.  
  15. Disconnect the return spring and clutch cable at the clutch release fork.
  16.  
  17. Remove the starter lower bolt and support the starter.
  18.  
  19. Unscrew the retaining bolts and disconnect the exhaust pipe from the manifold.
  20.  
  21. Remove the flywheel inspection cover.
  22.  
  23. Unscrew the rear transmission support mounting bolt. Support the transmission underneath the case and then remove the rear support from the frame.
  24.  
  25. Lower the transmission approximately 4".
  26.  
  27. Remove the transmission housing-to-engine blockbolts. Pull the transmission straight back and away from the engine.
  28.  
  29. Installation of the remaining components is in the reverse order of removal. Please note the following:
  30.  
    1. Be sure to lubricate the drive gear shaft with a light coat of grease before installing the transmission.
    2.  
    3. After installation, fill the transmission to the level of the filler hole. Please refer to under Fluids And Lubricants and the Capacities Chart for the correct type and quantity of lubricant. Lower the car.
    4.  

  31. Install the shift lever and check operation of the transmission.
  32.  

SHIFT LEVER REPLACEMENT





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Fig. Fig. 3Shift lever removal and installation-4-speed manual transmission shown

  1. Remove the floor console and/or boot retainer.
  2.  
  3. Raise the shift lever boot to gain access to the locknut on the lever. Loosen the locknut and unscrew the upper portion of the shift lever with the knob attached.
  4.  
  5. Remove the foam insulator to gain access to the control assembly bolts.
  6.  
  7. Remove the three bolts on the extension and remove the control assembly.
  8.  

Use caution when removing the clip on the control housing as the internal components are under spring pressure.

  1. Remove the locknut, boot retainer, and seat from the threaded end of the shift lever.
  2.  
  3. Remove the spring and guide from the forked end of the shift lever.
  4.  

To install:

  1. To assemble the shift lever, install the spring and guide on the forked end of the lever.
  2.  
  3. Install the seat, boot retainer and the locknut over the threaded end of the lever.
  4.  
  5. Assemble the components in the control housing and install the clip on the control housing.
  6.  
  7. Install the control assembly on the extension making sure that the fork at the lower end of the lever engages the shifter shaft lever arm pin. Tighten the shift lever retaining bolts to 35 in. lbs.
  8.  
  9. Install the foam insulator, boot, retainer, and/or floor console.
  10.  
  11. Slide the boot below the threaded portion of the shift lever and install the upper shift lever. Tighten the locknut.
  12.  

4-SPEED (70MM) TRANSMISSION OVERHAUL



Transmission Case


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Fig. Fig. 4Exploded view of the 70mm 4-speed manual transmission

  1. Place the transmission so that it is resting on the bell housing.
  2.  
  3. Drive the spring pin from the shifter shaft arm assembly and the shifter shaft, then remove the shifter shaft arm assembly.
  4.  
  5. Remove the 5 extension housing-to-case bolts and the extension housing.
  6.  
  7. Press down on the speedometer gear retainer, then remove the gear and the retainer from the mainshaft.
  8.  
  9. Remove the snaprings from the shifter shaft, then the Reverse shifter shaft cover, the shifter shaft detent cap, the spring, the ball and the interlock lock pin.
  10.  
  11. Pull the Reverse lever shaft outward to disengage the Reverse idler, then remove the idler shaft with the gear attached.
  12.  
  13. Remove the Reverse gear snapring, the Reverse countershaft gear and the gears.
  14.  
  15. Turn the case on its side and remove the clutch gear bearing retainer bolts, the retainer and the gasket.
  16.  
  17. Remove the clutch gear ball bearing-to-bell housing snapring, then the bell housing-to-case bolts.
  18.  
  19. Turn the case so that it rests on the bell housing, then expand the mainshaft bearing snapring and remove the case by lifting it off the mainshaft.
  20.  

Make sure that the mainshaft assembly, the countergear and shifter shaft assembly stay with the bell housing.

  1. Lift the entire mainshaft assembly complete with shifter forks and countergear from the bell housing.
  2.  

To assemble:
  1. Using a press, install the shielded ball bearing to the clutch gear shaft with the snapring groove up.
  2.  
  3. Install the snapring on the clutch gear shaft. Place the pilot bearings into the clutch gear cavity, using heavy grease to hold them in place.
  4.  
  5. Assemble the clutch gear to the mainshaft and the detent lever to the shift shaft with the roll pin.
  6.  
  7. Position the 1st/2nd gear shifter so that it engages the detent lever.
  8.  
  9. Assemble the 3rd/4th gear shifter fork to the detent bushing and slide the assembly on the shift shaft to place it below the 1st/2nd shifter fork arm.
  10.  
  11. Install the shifter assembly to the synchronizer sleeve grooves on the mainshaft.
  12.  
  13. With the front of the bell housing resting on wooden blocks, place a thrust washer over the hole for the countergear shaft. The thrust washer must be placed in the holes in the bellhousing.
  14.  
  15. Mesh the countershaft gears to the mainshaft gears and install this assembly into the bellhousing.
  16.  
  17. Turn the bellhousing on its side, then install the snapring to the ball bearing on the clutch gear and the bearing retainer to the bell housing. Use sealant on the 4 retaining bolts.
  18.  
  19. Turn the bell housing (so that it is resting on the blocks) and install the Reverse lever to the case using grease to hold it in place. When installing the Reverse lever, the screwdriver slot should be parallel to the front of the case.
  20.  
  21. Install the Reverse lever snapring and the roller bearing-to-countergear opening with the snapring groove inside of the case.
  22.  
  23. Using rubber cement, install the gasket on the bell housing. Before installing the case, make sure the synchronizers are in the Neutral position, the detent bushing slot is facing outward and the Reverse lever is flush with the inside wall of the case.
  24.  
  25. Expand the snapring in the mainshaft case opening and let it slide over the bearing.
  26.  
  27. Install the interlock lock pin with locking compound to hold the shifter shaft in place and the idler shaft so it engages with the Reverse lever inside the shaft.
  28.  
  29. Install the cover over the screwdriver arm to hold the Reverse lever in place.
  30.  
  31. Install the detent ball, the spring and the cap in the case, then the Reverse gear (with the chamfer on the gear teeth facing up). Push the Reverse gear onto the splines and secure with a snapring.
  32.  
  33. Install the smaller Reverse gear on the countergear shaft (with the shoulder resting against the countergear bearing) and secure with a snapring.
  34.  
  35. Install the snapring, the thrust washer and the Reverse idler gear (with the gear teeth chamfer facing down) to the idler shaft, then secure with the thrust washer and the snapring.
  36.  
  37. Install the shifter shaft snaprings and engage the speedometer gear retainer in the hole in the mainshaft (with the retainer loop toward the front), then slide the speedometer gear over the mainshaft and into position.
  38.  

Before installation, heat the gear to 175°F; use an oven or heat lamp, not a torch.

  1. Place the extension housing and the gasket on the case, then loosely install the two pilot bolts (one in the top right-hand corner and the other in the bottom left-hand corner) and the other three bolts. The pilot bolts must be installed in the right holes to prevent splitting the case.
  2.  
  3. Assemble the shifter shaft arm over the shifter shaft, align with the drilled hole near the end of the shaft, then drive the spring pin into the shifter shaft arm and shaft.
  4.  
  5. Turn the case on its side and loosely install the two pilot bolts through the bell housing and then the 4 retaining bolts.
  6.  

Mainshaft
  1. Separate the shift shaft assembly and countergear from the mainshaft.
  2.  
  3. Remove the clutch gear and the blocking ring from the mainshaft; make sure you don't lose any of the clutch gear roller bearings.
  4.  
  5. Remove the 3rd/4th gear synchronizer hub snapring and the hub, using an arbor press if necessary.
  6.  
  7. Remove the blocking ring and the 3rd speed gear. Using an arbor press, press the plates, then remove the ball bearing from the rear of the mainshaft. Remove the remaining parts from the mainshaft, keeping them in order for later reassembly.
  8.  

To assemble:
  1. With the rear of the mainshaft turned up, install the 2nd speed gear with the clutching teeth facing upward; the rear face of the gear will butt against the flange of the mainshaft.
  2.  
  3. Install a blocking ring (with the clutching teeth down) over the 2nd speed gear.
  4.  
  5. Install the 1st/2nd synchronizer assembly (with the fork slot down), then press it onto the splines on the mainshaft until it bottoms.
  6.  

Make sure the notches of the blocking ring align with the keys of the synchronizer assembly.

  1. Install the synchronizer hub-to-mainshaft snapring, then install a blocking ring (with the notches facing down) so they align with the keys of the 1st/2nd gear synchronizer assembly.
  2.  
  3. Install the 1st speed gear (with the clutching teeth down), then the rear ball bearing (with the snapring groove down) and press it into place on the mainshaft.
  4.  
  5. Turn the mainshaft up and install the 3rd speed gear (with the clutching teeth facing up); the front face of the gear will butt against the flange on the mainshaft.
  6.  
  7. Install a blocking ring (with the clutching teeth facing down) over the synchronizer surface of the 3rd speed gear.
  8.  
  9. Install the 3rd/4th gear synchronizer assembly (with the fork slot facing down); make sure the notches of the blocking ring align with the keys of the synchronizer assembly.
  10.  
  11. Install the synchronizer hub-to-mainshaft snapring and a blocking ring (with the notches facing down) so that they align with the keys of the 3rd/4th gear synchronizer assembly.
  12.  

Synchronizer Keys And Springs

The synchronizer hubs and the sliding sleeves are an assembly which should be kept together as an assembly; the keys and the springs can be replaced.

  1. Mark the position of the hub and the sleeve for reassembly.
  2.  
  3. Push the hub from the sliding sleeve; the keys will fall out and the springs can be easily removed.
  4.  
  5. Place the new springs in position (with one on each side of the hub) so that the three keys are engaged by both springs.
  6.  
  7. Place and hold the keys in position, then slide the sleeve into the hub aligning the marks made during disassembly.
  8.  

Extension Oil Seal
  1. Pry the oil seal and drive the bushing from rear of the extension housing.
  2.  
  3. Coat the inside diameter of the seal and bushing with transmission fluid and install them.
  4.  

Drive Gear Bearing Oil Seal

Pry out the old seal and install a new one making sure that it bottoms properly in its bore.

5-SPEED (77MM) TRANSMISSION OVERHAUL



Transmission Case


Click image to see an enlarged view

Fig. Fig. 5Exploded view of the 77mm 5-speed manual transmission-page 1 of 2



Click image to see an enlarged view

Fig. Fig. 6Key list for the 77mm 5-speed manual transmission-page 2 of 2

Many special tools and an arbor press are required to properly disassemble and assemble this transmission. Read the entire procedure carefully before starting the job.

  1. Remove the transmission from the vehicle as outlined in the appropriate section, then drain the lubricant from the transmission.
  2.  
  3. Using a pin punch and a hammer, carefully the offset lever-to-shift rail roll pin.
  4.  
  5. Remove the extension housing-to-case bolts. Remove the housing and offset lever as an assembly.
  6.  


CAUTION
DO NOT attempt to remove the housing with the offset lever in place.

  1. Remove the detent ball and the spring from the offset lever, then the roll pin from the extension housing or offset lever.
  2.  
  3. Remove the plastic funnel, the thrust bearing race and thrust bearing from the rear of the countershaft.
  4.  

The funnel and race may be found inside the extension.

  1. Remove the cover-to-case bolts and lift the cover assembly off of the case.
  2.  

Two of the cover bolts are alignment type dowel bolts. Mark the location of these bolts so that they may be reinstalled in their original locations.

  1. Place a wooden block under the 5th gear shift fork and drive the roll pin from the fork. The wood must be used to prevent damage to the shift rail.
  2.  
  3. Remove the following items from the rear of the countershaft.
  4.  
    1. The 5th gear synchronizer snapring.
    2.  
    3. The shift fork.
    4.  
    5. The 5th gear synchronizer sleeve.
    6.  
    7. The blocking ring.
    8.  
    9. The 5th speed drive gear.
    10.  

  5. Remove the 5th gear synchronizer springs and the inserts from the sleeve and the hub. Mark the sleeve and the hub so that they may be properly reassembled.
  6.  
  7. Remove the snapring from the 5th speed driven gear. Using the Kent-Moore puller tool No. J-25215, remove the driven gear.
  8.  
  9. Mark the front bearing cap and the case, so that the cap may be reinstalled in its proper position, then remove the front bearing cap.
  10.  
  11. Remove the front bearing brace and the end-play shim(s) from the bearing cap. Using a small prybar, carefully pry the oil seal from the cap.
  12.  
  13. Rotate the clutch shaft until the flat surface on the main drive gear faces the countershaft, then remove the clutch shaft and the main gear unit from the case.
  14.  

The clutch shaft bearing is pressed on; an arbor press must be used to replace the bearing if the bearing is rough.

  1. Remove the mainshaft rear bearing race and tilt the shaft upward, then remove the output shaft assembly from the case.
  2.  
  3. Unhook the overcenter spring from the front of the case.
  4.  
  5. Remove the Reverse lever C-clip and the pivot bolt.
  6.  
  7. Rotate the 5th/Reverse shift rail clockwise, to disengage it from the Reverse lever, then remove the rail from the rear of the case.
  8.  
  9. Drive the roll pin from the forward end of the Reverse idler shaft, then remove the Reverse idler shaft, the rubber O-ring and the gear from the case.
  10.  
  11. Remove the gear countershaft snapring and the spacer.
  12.  
  13. Insert a brass drift through the main drive gear opening in the front of the case, so that it contacts the countershaft gear assembly. Using an arbor press (positioned at the other end of the drift), carefully press the countershaft gear rearward (just enough) to remove the countershaft rear bearing.
  14.  

During the assembly, note that the bearing identification numbers should face outward.

  1. Move the countershaft assembly rearward, tilt it upward, then remove the assembly from the case. Mark the position of the front countershaft thrust washer (so that it may be reinstalled properly), then remove the washer from the case.
  2.  
  3. Remove the countershaft rear bearing spacer.
  4.  
  5. Drive the roll pin from the front of the Reverse idler shaft, then remove the shaft and the gear from the case.
  6.  

Mark the position of the gear, so that it may be reinstalled properly.

  1. Using an arbor press, remove the countershaft front bearing from the case.
  2.  
  3. Remove the clutch shaft front bearing.
  4.  
  5. Using a flat drift and a hammer, carefully tap out the rear extension and the adapter housing seal.
  6.  

To assemble:

If a replacement fastener is used, be sure that it matches the original EXACTLY. Many metric fasteners are used in this transmission.

  1. Apply a coat of Loctite® 601 to the outer cage of the front countershaft bearing, then press the bearing into its bore until it is flush with the case.
  2.  
  3. Apply a coat of petroleum jelly to the tabbed countershaft thrust washer, then install the washer so that its tab engages the corresponding depression in the case.
  4.  
  5. Tip the case on end and install the countershaft into the front bearing bore.
  6.  
  7. Install the countershaft rear bearing spacer and coat the rear countershaft bearing with petroleum jelly. Using the Kent-Moore installer tool No. J-29895 and the sleeve protector tool No. J-33032, install the rear countershaft bearing.
  8.  

When properly installed, the rear bearing will extend 3mm beyond the case surface.

  1. Position the Reverse idler gear into the case (with the shift lever groove facing rearward) and install the Reverse idler shaft from the rear of the case.
  2.  
  3. Install the shaft retaining pin.
  4.  
  5. Install the mainshaft assembly and the rear mainshaft bearing race into the case.
  6.  
  7. Using an arbor press, install the clutch shaft/main gear bearing (if removed).
  8.  
  9. Coat the main drive gear roller bearings with petroleum jelly and install them into the rear of the clutch shaft/main gear unit.
  10.  
  11. Install the thrust bearing and the race into the rear of the clutch shaft/main gear unit.
  12.  
  13. Install the 4th gear blocking ring onto the mainshaft.
  14.  
  15. Install the clutch shaft/main gear unit into the case, engaging the 3rd/4th synchronizer blocking ring.
  16.  
  17. Evenly and carefully, tap a new front bearing cap seal into place.
  18.  
  19. Install the front bearing race into the front bearing cap; do not install the front bearing cap shims.
  20.  
  21. Temporarily install the front bearing cap, without sealant.
  22.  
  23. Install the following:
  24.  
    1. The 5th/Reverse lever.
    2.  
    3. The pivot bolt.
    4.  
    5. The C-clip retainer.
    6.  


Coat the pivot bolt threads with nonhardening sealant (RTV is preferred). Also, be sure to engage the Reverse lever fork in the Reverse idler gear.

  1. Install the countershaft rear bearing spacer and the snapring.
  2.  
  3. Install the 5th speed gear onto the mainshaft.
  4.  
  5. Install the 5th/Reverse rail through the rear case opening and into the 5th/Reverse lever, then rotate the rail to engage it with the lever.
  6.  
  7. Position the 5th speed synchronizer assembly on the 5th speed shift fork, then slide the assembly onto the countershaft and the 5th/Reverse rail.
  8.  

The 5th/Reverse rail roll pin hole must be aligned with the hole of the 5th speed shift fork.

  1. Support the 5th speed shift fork rail and the fork with a block of wood, then drive the roll pin into place.
  2.  
  3. Install the following:
  4.  
    1. Thrust race against the 5th speed synchronizer hub, then retain with the snapring.
    2.  
    3. Needle type thrust bearing against the thrust race on the countershaft (coat the bearing and the race with petroleum jelly).
    4.  
    5. Lipped thrust race over the needle type thrust bearing.
    6.  
    7. Plastic funnel into the hole in the end of the countershaft gear.
    8.  

  5. Temporarily install the extension/adapter housing and the bolts.
  6.  
  7. Turn the case on end. Mount a dial indicator on the extension/adapter housing, so that the indicator needle contacts the end of the mainshaft, then zero the indicator needle.
  8.  
  9. Pull upward on the mainshaft to remove the end-play, then read the indicator and record the reading.
  10.  
  11. Select a shim pack which measures 0.025-0.130mm thicker than the end-play reading obtained during the previous step.
  12.  
  13. Position the case horizontally. Remove the front bearing cap and the bearing race, then install the shim pack. Reinstall the bearing race.
  14.  
  15. Apply a 1 / 8 " bead of RTV sealer on the front bearing cap-to-case mating surface. Align the case and the cap matchmarks. Install the bearing cap and tighten the bolts to 15 ft. lbs.
  16.  
  17. Recheck the end-play; no play should be evident.
  18.  
  19. Remove the extension and adapter housing, then carefully drive a new housing seal into place.
  20.  
  21. Move the shift forks of the cover and the synchronizer sleeves to their Neutral positions.
  22.  
  23. Apply a 1 / 8 " bead of RTV sealer to the cover-to-case mating surface. While aligning the shift forks with the synchronizer sleeves, carefully lower the cover assembly into the case.
  24.  
  25. Center the cover and to engage the Reverse relay lever, then install the alignment type (dowel) cover attaching bolts. Install the remaining cover bolts and tighten to 10 ft. lbs.
  26.  

The offset lever-to-shift rail roll pin hole must be positioned vertically.

  1. Apply a 1 / 8 " bead of RTV sealer to the extension/adapter housing-to-case mating surface and install the housing over the mainshaft.
  2.  

The shift rail must be positioned so that it just enters the shift cover opening.

  1. Install the detent spring into the offset lever and place the steel ball into the Neutral guide plate detent. Apply pressure on the steel ball with the detent spring and the offset lever, then slide the offset lever on the shift rail and seat the extension/adapter against the case.
  2.  
  3. Install the extension/adapter housing bolts and tighten to 25 ft. lbs.
  4.  
  5. Install the roll pin into the offset lever and the shift rail.
  6.  
  7. Install the damper sleeve in the offset lever. Coat the back up lamp switch threads with RTV sealant, then install the switch into the case and tighten to 15 ft. lbs.
  8.  

Mainshaft
  1. Remove the thrust bearing and the washer from the front of the mainshaft.
  2.  
  3. Scribe matchmarks on the 3rd/4th synchronizer hub and the sleeve to indicate their relationship for proper reassembly.
  4.  
  5. Remove the 3rd/4th synchronizer blocking ring, the sleeve and hub from the mainshaft as an assembly. Mark the positions of these items, so that they may be properly reassembled.
  6.  
  7. Remove the snapring, the tabbed thrust washer and the 2nd gear from the mainshaft.
  8.  
  9. Using an arbor press and the puller tool, remove the 5th speed gear from the mainshaft.
  10.  
  11. Slide the rear mainshaft bearing off of the mainshaft.
  12.  
  13. Remove the 1st gear thrust washer, the roll pin, the 1st speed gear and the blocking ring.
  14.  
  15. Scribe matchmarks on the 1st/2nd synchronizer hub and the sleeve for reassembly purposes.
  16.  
  17. Remove the insert spring and the inserts from the 1st/Reverse sliding gear, then the gear from the mainshaft.
  18.  


CAUTION
Do not attempt to remove the 1st/2nd/Reverse hub from the mainshaft as these parts are machined as a matched set from the factory.

To assemble:

  1. Lubricate the mainshaft and the gear bores with a liberal coating of transmission lubricant.
  2.  
  3. Align and install the 1st/2nd synchronizer sleeve on the mainshaft, using the matchmarks made during disassembly.
  4.  
  5. If removed, install the synchronizer inserts and the springs into the 1st/2nd synchronizer sleeve.
  6.  

The tanged end of each spring should be positioned on the same insert but that the open face of each spring should be opposite the other.

  1. Install the blocking ring and the 2nd speed gear onto the mainshaft.
  2.  
  3. Install the tabbed thrust washer and the 2nd speed gear snapring onto the mainshaft.
  4.  

Be sure that the washer tab is fully seated into the mainshaft notch.

  1. Install the blocking ring and the 1st speed gear onto the mainshaft.
  2.  
  3. Carefully drive the 1st gear roll pin into place, then install the 1st gear thrust washer.
  4.  
  5. Slide the mainshaft rear bearing onto the mainshaft.
  6.  
  7. Using an arbor press and the special tools, press the 5th speed gear onto the mainshaft.
  8.  
  9. Install the 3rd speed gear, the 3rd/4th synchronizer assembly and the thrust bearing onto the mainshaft; the synchronizer hub offset must face forward.
  10.  

Cover
  1. Place the selector arm plates and the shift rail in the Neutral position (centered).
  2.  
  3. Rotate the shift rail counterclockwise until the selector arm disengages from the selector arm plates. The selector arm roll pin will now be accessible.
  4.  
  5. Using a 3 / 16 " pin punch and a hammer, carefully drive out the selector arm roll pin, then remove the shift rail.
  6.  
  7. Remove the shift forks, the selector arm plates, the selector arm, the roll pin and the interlock plate.
  8.  
  9. Remove the nylon inserts and the selector arm plates from the shift forks. Mark the positions of the inserts and the plates so they may be properly reinstalled.
  10.  

To assemble:
  1. Attach the nylon inserts to the shift forks and install the selector arm plates into the shift forks.
  2.  
  3. If removed, apply sealer to the edges of the shift rail plug, then carefully tap the plug into place.
  4.  
  5. Coat the shift rail and the rail bores with petroleum jelly, then slide the rail into the cover until the end is flush with the inside edge of the cover.
  6.  
  7. With the offset of the 1st/2nd shift fork facing the rear of the cover, install the fork into the cover and push the shift rail through the fork.
  8.  

The the 1st/2nd fork is the larger of the two forks.

  1. Place the selector arm and the C-shaped interlock plate into the cover, then insert the shift rail through the arm.
  2.  

The widest part of the interlock plate must face away from the cover and the selector arm roll pin hole must face downward, toward the rear of the cover.

  1. With the offset of the 3rd/4th shift fork facing the rear of the cover, install the fork into the cover. The 3rd/4th shift fork selector arm plate must be positioned under the 1st/2nd arm plate. Push the shift rail completely forward, through the 3rd/4th fork and into the cover bore.
  2.  
  3. Rotate the shift rail so that the forward selector arm plate faces away from but parallel to the cover.
  4.  
  5. After aligning the holes, install the selector arm-to-shift rail roll pin.
  6.  

To prevent the roll pin from contacting the selector arm plates when shifting, the roll pin must be installed flush with the surface of the selector arm.

  1. Install the O-ring into the groove of the shift rail oil seal.
  2.  
  3. Installation of the shift rail oil seal should be performed as follows:
  4.  
    1. Install the Kent-Moore tool No. J-26628-2 over the threaded end of the shift rail.
    2.  
    3. Lubricate the lip of the oil seal with petroleum jelly.
    4.  
    5. Slide the seal over the protector tool and onto the shift rail.
    6.  
    7. Using the Kent-Moore seal installer tool No. J-26628-1, seat the seal in the cover.
    8.  


Cleaning and Inspection

The parts (except the nylon or plastic) should be thoroughly cleaned in cleaning solvent. The nylon or plastic parts, which are to be reused should just be wiped clean with a cloth. The assembled roller bearings should be dried with compressed air.


CAUTION
Do not spin the bearings with the compressed air as they could shatter and cause personal injury. The individual bearing rollers, washers and thrust bearings should be allowed to air dry after cleaning, though they may be wiped with a clean cloth.

Inspect the parts for excessive wear and/or damage such as scoring, cracks, nicks or rough edges; replace the defective parts. To check the condition of the assembled bearings, first clean and dry them, then coat the bearings with light engine oil. Slowly spin the bearings by hand and check for any signs of roughness. If the bearing does not feel perfectly smooth, it should be replaced.

5-SPEED (69.5MM) TRANSMISSION OVERHAUL



Transmission Case


Click image to see an enlarged view

Fig. Fig. 7Exploded view of the 69.5mm 5-speed manual transmission

The use of an arbor press is required to properly disassemble and assemble this transmission. Read the entire procedure carefully before starting the job.

  1. Remove the drain plug and allow the lubricant to drain from the case.
  2.  
  3. Remove the throwout bearing and the fork from the transmission as outlined in the appropriate car section.
  4.  
  5. Remove the drive gear bearing retainer. If damaged, remove the ball stud.
  6.  
  7. Remove the Belleville spring from the front of the drive gear bearing.
  8.  
  9. Remove the bolt, the retainer and the speedometer driven gear from the side of the case.
  10.  
  11. Remove the shift lever quadrant from the extension housing.
  12.  
  13. Remove the back up light switch.
  14.  
  15. Remove the extension housing bolts and the housing.
  16.  
  17. Remove the snaprings, the speedometer drive gear, the spacer and the bearing from the mainshaft.
  18.  
  19. Remove the snapring, then the thrust washer and the lock ball from the driveshaft.
  20.  
  21. Remove the large snapring from the main drive gear bearing.
  22.  
  23. Remove the following components from the case as an assembly:
  24.  
    1. The center support
    2.  
    3. The mainshaft
    4.  
    5. The countergear
    6.  
    7. The drive gear
    8.  

  25. Using a drift punch and a hammer, carefully drive the roll pins from the 1st/2nd, the 3rd/4th and the 5th/Reverse shift forks. Support the shaft ends with a bar or a block of wood to prevent damage to these components.
  26.  
  27. Remove the detent spring plate mounting bolts, the detent spring plate, the 3 springs and the balls from the center support.
  28.  
  29. Remove the shifter shafts from the center support, the shift forks from the shafts and the interlock pins from the center support.
  30.  
  31. Move the 1st/2nd synchronizer sleeve to the 1st gear position and the 3rd/4th synchronizer sleeve into the 3rd gear position.
  32.  
  33. Using the Kent-Moore holdling fixture tool No. J-29768, install it on the end of the drive gear shaft and countergear. Remove the countergear retaining nut and the washer.
  34.  
  35. Using a puller, remove the ball bearing and the 5th speed gear from the countershaft.
  36.  
  37. Remove the 5th gear, the blocking ring and the needle bearing from the mainshaft.
  38.  
  39. Remove the self locking nut from the Reverse idler gear shaft.
  40.  
  41. Remove the thrust washers and the Reverse idler gear from the Reverse idler gear shaft.
  42.  
  43. Bend the locking retainer of the mainshaft nut away from the nut, then remove the mainshaft nut.
  44.  
  45. Remove the 5th/Reverse synchronizer locking retainer, the 4th/Reverse synchronizer assembly, the Reverse gear, the needle bearing, the collar and the thrust washer from the mainshaft.
  46.  
  47. Remove the Reverse gear from the countergear and the holding fixture (installed during Step 17).
  48.  
  49. Move the synchronizer sleeves back to their Neutral positions.
  50.  
  51. Expand the countergear bearing snapring (using snapring pliers) and gently tap on the front of the center support. Expand the mainshaft bearing snapring and move the mainshaft inward then remove the countergear and the mainshaft.
  52.  
  53. Remove the drive gear, the needle bearing and the blocking ring from the end of the mainshaft.
  54.  

To assemble:
  1. If removed, install the countergear and the mainshaft snaprings into the center support. Also, install the Reverse idler shaft into the center support.
  2.  
  3. Install the drive gear onto the front of the mainshaft and engage it with the countergear.
  4.  
  5. Install the holding fixture in the same manner as the disassembly, in Step 17.
  6.  
  7. With the mainshaft and the countergears meshed, slide the center support onto the mainshaft. Expand the mainshaft snapring and continue to push the center support on until the mainshaft bearing groove aligns with the snapring. Release the mainshaft snapring to lock the mainshaft bearing into place. Repeat the same procedure to seat the countergear snapring.
  8.  
  9. Move the synchronizer sleeves to engage both the 1st and the 3rd gear tangs in order to lock the gears.
  10.  
  11. Install the Reverse gear onto the countergear.
  12.  
  13. Install the thrust washer on the mainshaft (with the oil groove facing the rear), then install the collar, the needle bearing and the Reverse gear onto the mainshaft.
  14.  
  15. Install the 5th/Reverse synchronizer (with the face of the higher clutch hub boss facing the Reverse gears).
  16.  
  17. Install the locking retainer and the mainshaft nut onto the mainshaft, then tighten the nut to 94 ft. lbs. and then bend the locking retainer tabs to lock the nut.
  18.  
  19. Install the thrust washers and the Reverse idler gear on the Reverse idler gear shaft. Thread a new self locking nut onto the Reverse idler shaft and tighten the nut to 80 ft. lbs.
  20.  

The flange of the plate side thrust washer must be fitted to the center support.

  1. Install the synchronizer blocking ring and the 5th speed gear (with the needle bearings) onto the mainshaft.
  2.  
  3. Install the 5th speed gear (of the countergear), the ball bearing, the washer and a new self locking nut onto the rear of the countergear, then tighten the nut to 80 ft. lbs.
  4.  
  5. Remove the holding fixture and move the synchronizer sleeves back to their Neutral positions.
  6.  
  7. Grease the interlock pins and install them into the center support.
  8.  
  9. Place the shift forks into position on the synchronizer sleeves. Install the shifter shafts through their respective forks from the rear of the center support, except the 5th/Reverse shaft, which is installed from the front of the support.
  10.  
  11. Install the three detent balls, the springs, the detent plate gasket and the detent plate, then tighten the detent plate bolts to 14 ft. lbs.
  12.  
  13. Using a drift punch and a hammer, carefully install the retaining pins into the shift forks. Remember to support the shafts with a bar or a block of wood to prevent damage.
  14.  
  15. If removed, lubricate the countergear needle bearing and install it into the front of the case. The bearing should be driven into place while a socket is positioned on the outer bearing race.
  16.  
  17. Install a new center support-to-case gasket on the case and the center support/mainshaft/countergear/drive gear assembly into the case.
  18.  
  19. Install the large snapring onto the shaft of the drive gear bearing.
  20.  
  21. Install the lock ball, the thrust washer and the snapring onto the mainshaft.
  22.  
  23. Using a feeler gauge, check the clearance between the 5th speed gear (of the mainshaft) and its thrust washer. The clearance should be 0.25-0.40mm. If necessary, adjust the clearance by purchasing a thrust washer of the correct thickness which will replace the existing washer. The thrust washers are available in thickness ranging from 7.8-8.3mm in 0.08mm increments.
  24.  

Use care when removing and installing the snapring; it must be replaced if it becomes distorted.

  1. Install these parts on the mainshaft behind the 5th gear snapring, in this order:
  2.  
    1. The ball bearing.
    2.  
    3. The snapring.
    4.  
    5. The speedometer gear clip.
    6.  
    7. The speedometer drive gear.
    8.  

  3. Using a new gasket, attach the extension housing to the center support and tighten the bolts to 27 ft. lbs.
  4.  
  5. Using a new gasket, install the shift lever quadrant onto the extension housing and tighten the bolts to 14 ft. lbs.
  6.  
  7. Install the speedometer driven gear and tighten the bolt to 14 ft. lbs.
  8.  
  9. Install the back up light switch into the extension housing.
  10.  
  11. Install the belleville washer in the front of the drive gear bearing.
  12.  

The dished side of the washer should face the bearing.

  1. Using a new gasket, install the drive gear bearing retainer. Before installing the three lower bearing retainer bolts, coat the threads with Permatex® No. 2 sealer (or its equivalent). Tighten the bearing retainer bolts to 14 ft. lbs.
  2.  
  3. Install the throw out bearing and the fork.
  4.  
  5. Install the transmission according to the procedure in the Chevette car section.
  6.  

Mainshaft
DISASSEMBLY
  1. Using an arbor press and the Kent-Moore tool No. J-22912-01, remove the mainshaft rear bearing.
  2.  
  3. Remove the thrust washer, the 1st speed gear, the needle bearings and the spacer.
  4.  
  5. Remove the 1st/2nd synchronizer assembly, the 2nd speed gear and the needle bearings.
  6.  
  7. Remove the snapring from in front of the 3rd/4th synchronizer and slide the synchronizer off the mainshaft.
  8.  

Drive Gear Bearing
  1. Remove the snapring from the drive gear shaft.
  2.  
  3. Using an arbor press and the Kent-Moore tool No. J-22912-01, press the drive gear shaft through the bearing.
  4.  
  5. To install, reverse the removal procedures.
  6.  

Countergear Bearing

The bearing is removed in the same manner as the drive gear bearing, using the same special tool and an arbor press. Note that the groove on the bearing is installed towards the rear of the transmission.

Extension Housing Or Drive Gear Retainer Seals

Using a small prybar, pry the seals from the housing. Install the new seals by carefully tapping them into place.

Mainshaft
ASSEMBLY
  1. Install the 3rd speed gear (with the needle bearings) onto the front of the mainshaft.
  2.  

The coned side of the gear is installed toward the front of the mainshaft.

  1. Install the 3rd/4th synchronizer assembly onto the mainshaft, with the large chamfered end facing the front of the case; retain the synchronizer with the snapring.
  2.  
  3. Install the 2nd speed gear (with the needle bearings) onto the rear of the mainshaft.
  4.  

The coned side of the gear is installed facing the rear of the mainshaft.

  1. Install the 1st/2nd synchronizer assembly onto the mainshaft, with the large chamfered end facing the rear of the case.
  2.  
  3. Install the 1st speed gear (with the spacer and the needle bearings), with the coned end facing the front of the case.
  4.  
  5. Install the 1st gear thrust washer, with the slots of the washer facing the gear.
  6.  
  7. Press the rear bearing onto the mainshaft according to the previous procedure under "Removal and Installation".
  8.  

 
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