Starter Overhaul 28-MT Reduction and Drive Disa

1. Disassemble the insulated brush screws. Move the brush holder assembly with the brushes slightly away from the frame and the field assembly to reach across with a screwdriver and remove the screws.
2. Disassemble the frame and the field assembly.
3. Disassemble the grounded brush screws.
4. Disassemble the brushes if they need replacement.
5. Disassemble the brush springs using the following procedure:

•	Grasp the brush end of each brush spring with needle nose pliers.

•	Twist the spring end away from the brush.

•	Remove the brush.

Starter Overhaul 28-MT Driveshaft and Clutch Di

Disassembly of the driveshaft and clutch group is not required unless it is necessary to clean, inspect, or replace one or more parts of the group separately.

1. Disassemble the stop rings and the pinion stop.
2. Position the driveshaft and clutch group on a work bench with the internal gear end down.



3. Fabricate a tube approximately 22 mm wide (2). Drive the pinion stop toward the clutch drive assembly until it clears the stop rings.
4. Pry the stop rings out of the driveshaft groove and slide them off the end of the shaft. Do not scratch the driveshaft.
5. Inspect the edges of the shaft groove for burrs that may have been formed through repeated cranking cycles. These burrs may make removal of the pinion stop and clutch drive assembly difficult.
6. Slide the pinion stop off the driveshaft. Discard the old pinion stop and stop rings. New parts must be used at assembly.
7. Disassemble the driveshaft support from the driveshaft. Do not remove the bearing from the driveshaft unless replacement is required.

Starter Overhaul SD-260 Drive-End Frame Assem

1. Wipe the armature shaft clean.
2. Lubricate the area that will be under the drive assembly. Use lubricant GM P/N 1960954 or equivalent.
3. Wipe the drive assembly clean
4. Assemble the drive assembly onto the armature shaft.
5. Assemble the pinion stop collar with the flat side of the collar toward the drive pinion.



6. Assemble the new retaining ring onto the armature shaft. Slide the ring down the shaft until it seats in the shaft grove.



7. Assemble the thrust collar onto the shaft with the small flange toward the retaining ring. Using two sets of pliers, push the pinion stop collar and the thrust collar together to snap the stop collar onto the retaining ring
8. Inspect the drive end bearing. If no lubrication is visible, replace the bearing using a suitable driver and hammer. Do not lubricate the bearing.
9. Assemble the new drive end bearing by pressing it until it is recessed 1.6 mm (0.06 in) into the casing. It is prelubricated. Do not add lubricant.
10. Assemble the shift lever to the drive assembly by spreading the arms slightly to snap it onto the buttons on the drive collar.



11. Assemble the plunger to the lever by snapping it into place. Note which side of the lever is up.
12. Assemble the armature shaft into the drive end bearing while sliding the shift lever retainer into the slot on the drive end housing.
13. Assemble the spring onto the plunger.
14. Assemble the plug.
15. Assemble the solenoid and clamp onto the drive end frame, aligning the M terminal with the field connector.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

16. Assemble the solenoid clamp retaining screws.

Tighten
Tighten the solenoid clamp retaining screws to 11 N·m (95 lb in).

Starter Overhaul SD-260 Frame and Field Assem

1. Assemble the frame and field assembly onto the armature.

•	Clean the contact faces of the brushes and the commutator with a soft cloth.

•	Push the brushes into the brush holders and hold them in place while installing the frame.

•	Align the scribe mark on the frame with the scribe mark on the drive end frame.

•	Release the brushes onto the commutator, making sure all four brushes move freely and contact the commutator.

2. Assemble the brake washer to the armature assembly.
3. Assemble the drain tube to the frame, if it was removed.
4. Assemble the drive end frame to the field frame.

•	If the drive end frame bearing shows no lubrication or looks damaged, replace it.

•	Recess the new bearing 2 mm (0.08 in) into the housing. The bearing is pre-lubricated. Do not add any lubricant.

5. Assemble the identification tag over the hole in the drive end frame with the fluted end around the bearing well.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

6. Assemble the through-bolts in their original locations

Tighten
Tighten the bolts to 8.5 N·m (75 lb in).

7. Assemble the motor field lead over the motor terminal on the solenoid.
8. Assemble the field lead attaching nut.

Tighten
Tighten the nut to 11 N·m (95 lb in).

9. Assemble the solenoid shield onto the protruding ends of the solenoid attachment screws.
10. Assemble the shield attaching nuts.

Tighten
Tighten the shield attaching nuts to 8 N·m (70 lb in).

Starter Overhaul 28-MT Driveshaft and Clutch As

If disassembled, position the driveshaft on a work surface with the internal gear end down. Assemble the driveshaft and clutch group in the following way:

Important: If the center support bearing is being replaced, install it on the driveshaft.

1. Install the driveshaft support to the driveshaft, seating the bearing in the support.
2. Install the clutch drive assembly to the driveshaft.



3. Install the new pinion stop onto the driveshaft.

•	Slide the pinion stop onto the driveshaft until the recess for the stop rings faces up.

•	Install the stop rings into the groove in the driveshaft.

•	Pick the assembly up and support it under the pinion stop. A metal block, with a U-shaped cutout that will slide over the shaft between the pinion gear and stop, can be clamped in a vise to provide support.

•	Make sure the stop rings are fully seated in the pinion stop recess. Stake the upper edge of the pinion stop over the stop ring at four equally spaced places. Do not allow the staked metal to contact the driveshaft.

Starter Overhaul 28-MT Reduction and Drive Unit

Important: 

•	If the drive end bushing and plug are being replaced, install them in the drive housing.

•	Lubricate the drive end housing bushing, the shift lever and the driveshaft.

1. Install the arms on the shift lever with the shift collar onto the driveshaft and clutch group.
2. Installed the assembled shift lever and the driveshaft and clutch group into the drive housing.

•	Align the holes in the driveshaft support with those in the drive housing.

•	Make sure that the driveshaft support is fully seated in the drive housing and that the driveshaft bearing remains fully seated in the driveshaft support.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

3. Install the shift lever screw, washer, and nut.

Tighten
Tighten the nut to 4.5 N·m (40 lb in).

4. Install the plate, if used, and the drive housing.
5. Install the washers in the same number and position as noted at disassembly.
6. Install the armature support bracket to the drive housing. Align the mark made prior to disassembly with that on the drive housing.
7. Install the drive housing.

Tighten
Tighten the drive housing bolts to 8.5 N·m (75 lb in).

Starter Overhaul 28-MT Frame and Field Assembly

1. Install the brush springs using the following procedure:

1.1.	Start each brush spring onto the post on the brush holder assembly just enough to hold the inside end of spring from turning.

1.2.	Grasp the free end of the spring with needle nose pliers and twist it to the right over the top of the brush socket.

1.3.	Push the spring fully onto the post then release the free end to engage the notch in the brush socket.

Notice: Brush leads may be damaged by excessive handling. Do not overflex the leads near the clip welds or the clips may break




2. Install the brushes, if they were removed.

2.1.	Ensure that the insulated brushes go into the brush sockets of the brush holder assembly that mounts on the insulation.

2.2.	To install each brush, grasp the free end of the brush spring with needle nose pliers, twist it to the right to clear the brush socket, then insert the brush partly into the brush socket.

2.3.	Gradually release the springs so that its end contacts the side (not end) of the brush. This will hold the brushes retracted until after the brush holder is installed over the armature commutator.

3. Install the grounded brush screws.

3.1.	Position the terminals of the grounded brush leads behind the terminal tabs on the brush holder.

3.2.	Insert the brush screws through the terminal tabs on the brush holder and thread them into the brush lead terminals.

Tighten
Tighten the grounded brush screws to 1.5 N·m (13 lb in).




4. Install the frame and field assembly to the brush holder assembly.

4.1.	Position the brush holder assembly (with installed brushes) over the terminal end of the frame and field assembly.

4.2.	Attach the terminals of the insulated brush leads to the conductors in the frame and field assembly with the insulated brush screws.

Tighten
Tighten the insulated brush screws to 1.5 N·m (13 lb in).

Starter Overhaul SD-260 Solenoid Disassembly

1. Clean the outside of the starter housing.
2. Make scribe marks to show the relationship of the drive end frame, frame and field assembly, and the end frame to aid in assembly.
3. Note the position of the through-bolts.
4. Models with solenoid shield:

•	Solenoid shield nuts from the solenoid clamp screws.

•	Shield from the solenoid.

•	Motor lead attaching nut and lead from the solenoid.

•	Solenoid clamp attaching screws, clamp, and solenoid from the frame assembly.

Starter Overhaul SD-260 Frame and Field Disass

1. Disassemble the through bolts from the end frame.
2. Disassemble the end frame.
3. Disassemble the brake washer from the armature assembly.
4. Disassemble the frame and field from the armature/drive and frame assembly.

Starter Overhaul SD-260 Drive-End Frame

1. Disassemble the plug from the drive end frame assembly.



2. Disassemble the armature with the drive assembly, shift lever, plunger and return spring from the drive end frame.
3. Disassemble the return spring from the plunger.
4. Disassemble the plunger from the shift lever.



5. Disassemble the shift lever from the drive assembly by spreading the lever arms slightly to snap them off the mating buttons on the drive collar.
6. Disassemble the drive assembly from the armature shaft in the following way:

•	Remove the thrust collar away from the armature shaft.

•	Drive the pinion stop collar away from the pinion stop retainer ring by sliding a metal cylinder onto the armature shaft. Strike the metal cylinder against the stop collar with a hammer.

•	Spread the pinion stop retainer ring to remove it from the groove in the armature shaft. Discard the old ring. The retainer ring must be replaced.

•	Slide the stop collar and the drive assembly off the armature shaft.

Starter Overhaul 28-MT Frame and Field Disassem

1. Disassemble the insulated brush screws. Move the brush holder assembly slightly away from the frame and the field assembly in order to reach across with a screwdriver, then remove the screws.
2. Disassemble the frame and the field assembly.
3. Disassemble the grounded brush screws.
4. Disassemble the brushes if they need replacement.
5. Disassemble the brush springs if they need replacement. Grasp the brush end of each brush spring with needle nose pliers. Twist the spring end away from the brush and remove the brush.