Starter Assembly

Models SD205 and SD255

Starter Motor - Disassembled View (SD205/255):

Armature Shaft And Drive Assembly:

Testing Solenoid Winding:

INSTALL OR CONNECT
1. Drive assembly to armature shaft as follows:
A. Lubricate area on armature shaft that will be under drive assembly lightly with GM lubricant P/N 1960954 or equivalent.
B. Drive assembly onto armature shaft with pinion away from armature.
C. Pinion stop collar onto armature shaft.
D. New pinion stop retainer ring into groove on shaft. Do not reuse old ring.
E. Thrust collar to end of shaft with flange toward retainer ring. Use pliers to snap pinion stop collar over retainer ring.
Inspect
- Bushing (SD205) or Bearing (SD255) in drive end housing. If damaged, replace drive end housing. If dry, lubricate with GM lubricant P/N 1960954 or equivalent. Avoid excessive grease.
2. Shift lever yoke to drive collar, then armature/drive/lever assembly into drive end housing.
3. Shift lever shaft through holes in drive end housing and shift lever, then secure with retainer. Place return spring onto plunger.
4. Solenoid over plunger by depressing spring, aligning to drive end housing. Install attaching screws.
5. Frame and field assembly as follows:

Testing Field For Open:

Testing Field For Ground:

Brush Holder:

Inspect
- Brushes. If damaged or excessively worn replace brushes.
- Use soft cloth to clean contact face of brushes in frame and field assembly.
A. Apply sealer GM P/N 1050026 or equivalent to solenoid flange where frame and field will contact it.
B. Push brushes into brush holders and hold.
C. Install frame and field assembly over armature, aligning properly to drive end housing.
D. Release brushes onto commentator. Be sure all four brushes move freely in holders and are in contact with commentator.
6. Brake washer onto armature shaft.
Inspect
- Bushing (SD205) or Bearing (SD255) in commentator end frame. If damaged, replace commentator end frame. If dry, lubricate with G.M. Lubricant P/N 1960954 or equivalent. Avoid excessive grease.
7. Commentator end fame onto armature shaft, aligning with frame and field assembly.
8. Identification tag onto one thru bolt, then two thru bolts to motor. If thru bolts have different heads, place as noted during disassembly.
Tighten
- Bolts to 8.5 N.m (75 lb. in.).
Measure
- Pinion clearance as follows:

Checking Pinion Clearance:

CAUTION: Keep fingers, tools, and other objects away from opening in drive end housing while making electrical connections. The strong shuffling action of the solenoid could cause personal injury or damage as the drive pinion moves Into cranking position.

A. Secure starting motor in vise or equivalent fixture so that opening in drive end housing is accessible for measurement.
B. Assure that field lead is disconnected and insulated from solenoid terminal.
C. Connect positive lead from a 12-volt battery to the solenoid "S" terminal. Connect negative lead from battery to clean ground on motor housing. This energizes hold-in coil.
D. Momentarily ground solenoid "M" terminal to motor housing. This energizes pull-in coil in solenoid and causes drive pinion to move into cranking position. Drive pinion will stay in this position when momentary ground is removed.
E. Press on drive just enough to take up any free movement of the pinion on the shaft. Use feeler gages to check clearance between end of pinion and pinion stop collar. Clearance should be 0.25 to 4.06 mm (0.010 inch to 0.160 inch).
F. Disconnect negative (ground) lead from motor housing (drive pinion will retract into drive end housing), then disconnect positive lead from "S" terminal.
G. If clearance is outside specifications, recheck motor for proper assembly and for worn or damaged parts in shift mechanism and drive assembly. Replace worn parts.
H. Field lead to solenoid terminal.
Tighten
- Screw to 8.5 N.m (75 lb. in.).