REMOVAL & INSTALLATION
See Figures 1, 2, 3, 4 and 5
Starter removal on some models may necessitate the removal of the front support which runs from the corner of the frame to the front crossmember. If so, loosen the mounting bolt which attaches the support the frame first, then remove the crossmember bolt and swing the support out of the way.
The starters on some engines require the addition of shims to provide proper clearance between the starter pinion gear and the flywheel. These shims are available in 0.015 in. sizes from Chevrolet dealers. Flat washers can be used if shims are unavailable.
- Disconnect the negative battery cable.
- Raise and support the vehicle safely using jackstands.
If access to the wiring is difficult, the starter may be partially lowered before disconnecting it, but be careful not to stretch or damage the wiring.
- Disconnect all wiring from the starter solenoid. Replace each nut as the connector is removed, as thread sizes differ from connector to connector. Note or tag the wiring positions for installation purposes.
- If equipped, remove the front bracket from the starter. On engines with a solenoid heat shield, remove the front bracket upper bolt and detach the bracket from the starter.
- Remove the starter mounting bolts. If a starter shim tab can be seen protruding out from between the mating surfaces of the starter and the block, remove the outer bolt first, then loosen the inner bolt. With the outer bolt removed and the inner loosened, most shims may be grasped and pulled from the top of the starter at this point. Once the bolts are removed, lower the starter front end first, and remove the unit from the car.
If no shim tab could be seen, yet shims or flat washers fall from the starter as it is withdrawn, stop and attempt to determine their locations. If possible, gather the shims for reuse during assembly. Shims without tabs must be positioned on the starter prior to installation, but the bolts may be held through the starter assembly in order to hold the shims in position.To install:
- If flat washers or shims without tabs were found on removal, position them on top of the starter using the mounting bolts to hold them in position.
- Position the starter to the engine block and loosely install the mounting bolts. If tabbed shims were withdrawn during removal, position them before the outer mounting bolt is threaded.
- Once the starter and shims are properly positioned, tighten the two mounting bolts to 25-35 ft. lbs. (34-47 Nm).
- If equipped, install the front bracket and/or heat shield to the starter assembly.
- Attach the starter wiring to the solenoid, as noted during removal.
- Remove the jackstands and carefully lower the vehicle.
- Connect the negative battery cable.
SHIMMING THE STARTER
See Figures 6, 7 and 8
Starter noise during cranking and after the engine fires is often a result of too much or tool little distance between the starter pinion gear and the flywheel. A high pitched whine during cranking (before the engine fires) can be caused by the pinion and flywheel being too far apart. Likewise, a whine after the engine starts (as the key is released) is often a result of the pinion-flywheel relationship being too close. In both cases flywheel damage can occur. Shims are available in 0.015 in. sizes to properly adjust the starter on its mount. In order to check and adjust the shims, you will also need a flywheel turning tool, available at most auto parts stores or from any auto tool store or salesperson.
If your car's starter emits the above noises, follow the shimming procedure below:
- Disconnect the negative battery cable.
- Raise and support the vehicle safely using jackstands.
- Remove the flywheel inspection cover on the bottom of the bellhousing.
- Using the flywheel turning tool, turn the flywheel and examine the flywheel teeth. If damage is evident, the flywheel should be replaced.
- Insert a screwdriver into the small hole in the bottom of the starter, then move the starter pinion and clutch assembly so the pinion and flywheel teeth mesh. If necessary, rotate the flywheel so that a pinion tooth is directly in the center of the two flywheel teeth and on the centerline of the two gears, as shown in the accompanying illustration.
- Check the pinion-to-flywheel clearance by using a 0.020 in. wire gauge (a spark plug wire gauge may work here, or you can make your own). Make sure you center the pinion tooth between the flywheel teeth and the gauge - NOT in the corners, as you may get a false reading. If the clearance is under this minimum, shim the starter away from the flywheel by adding shim(s) one at a time to the starter mount. Check clearance after adding each shim.
- If the clearance is a good deal over 0.020 in. (in the vicinity of a 0.050 in. plug), shim the starter towards the flywheel. Broken or severely mangled flywheel teeth are also a good indicator that the clearance here is too great. Shimming the starter towards the flywheel is done by adding shims to the outboard starter mounting pad only. Check the clearance after each shim is added. A shim of 0.015 in. at this location will decrease the clearance about 0.010 in.
See Figures 9, 10, 11, 12, 13 and 14Drive Replacement
- Disconnect the field coil straps from the solenoid.
- Remove the through-bolts, and separate the commutator end frame, field frame assembly, drive housing, and armature assembly from each other.
On diesel starter, remove the insulator from the end frame. The armature on the diesel starter remains in the drive end frame. On diesel starters, remove the shift lever pivot bolt. ON the diesel 25 MT starter only, remove the center bearing screws and remove the drive gear housing from the armature shaft. The shift lever and plunger assembly will now fall away from the starter clutch.
- Slide the two piece thrust collar off the end of the armature shaft.
- Slide a suitably sized metal cylinder, such as a standard 1 / 2 in. pipe coupling, or an old pinion, onto the shaft so that the end of the coupling or pinion butts up against the edge of the pinion retainer.
- Support the lower end of the armature securely on a soft surface, such as a wooden block, and tap the end of the coupling or pinion, driving the retainer towards the armature end of the snapring.
- Remove the snapring from the groove in the armature shaft with a pair of pliers. Then, slide the retainer and starter drive from the shaft.
- Lubricate the drive end of the armature shaft with silicone lubricant and then slide the starter drive onto the shaft with the pinion facing outward. Slide the retainer onto the shaft with the cupped surface facing outward.
- Again support the armature on a soft surface, with the pinion at the upper end. Center the snapring on the top of the shaft (use a new snapring if the original was damaged during removal). Gently place a block of wood flat on top of the snapring so as not to move it from a centered position. Tap the wooden block with a hammer in order to force the snapring around the shaft. Then, slide the ring down into the snapring groove.
- Lay the armature down flat on the surface you're working on. Slide the retainer close up on to the shaft and position it and the thrust collar next to the snapring. Using two pairs of pliers on opposite sides of the shaft, squeeze the thrust collar and the retainer together until the snapring is forced into the retainer.
- Lube the drive housing bushing with a silicone lubricant. Then, install the armature and the clutch assembly into the drive housing, engaging the solenoid shift lever yoke with the clutch, and positioning the front of the armature shaft into the bushing.
On non-diesel starters the shift lever may be installed in the drive gear housing first. On the 25 MT diesel starter only, install the center bearing screws and the shift lever pivot bolt, and tighten securely.
- Apply a sealing compound approved for this application onto the drive housing; then position the field frame around the armatures shaft and against the drive housing. Work slowly and carefully to prevent damaging the starter brushes.
- Lubricate the bushing in the commutator end frame with a silicone lubricant, place the leather brake washer onto the armature shaft, and then slide the commutator end frame over the shaft and into position against the field frame. Line up the bolt holes, then install and tighten the through-bolts.
- Reconnect the field coil straps to the MOTOR terminal of the solenoid.
If replacement of the starter drive fails to cure improper engagement of starter pinion to flywheel, there are probably defective parts in the solenoid and/or shift lever. The best procedure would probably be to take the assembly to a shop where a pinion clearance check can be made by energizing the solenoid on a test bench. If the pinion clearance is incorrect, disassemble the solenoid and shift lever, inspect, and replace worn parts.
- Disassemble the starter by following Steps 1 and 2 of the Drive Replacement procedure above.
- Replace the brushes one at a time to avoid having to mark the wiring. For each brush; remove the brush holding screw; remove the old brush and position the new brush in the same direction (large end toward center of of field frame), position wire connector on top of brush, line up holes, and reinstall screw. Make sure the screw is snug enough to ensure good contact.
- Reassemble starter according to the applicable steps above.
- Remove the screw and washer from the motor connector strap terminal.
- Remove the two solenoid retaining screws.
- Twist the solenoid housing clockwise to remove the flange key from the keyway in the housing. Then remove the housing.
- To install the unit, place the return spring on the plunger and place the solenoid body on the drive housing. Turn counterclockwise to engage the flange key. Place the two retaining screws in position, then install the screw and washer which secures the strap terminal. Install the unit on the starter.