SERVICE MANUAL UPDATE-SEC. 7A 2B AUTO TRANSAXLE UNIT REPAIR

Subject: JF403E AUTOMATIC TRANSAXLE UNIT REPAIR

Model and Year: 1991-93 GEO STORM

SERVICE MANUAL UPDATE

This bulletin updates service information in JF403E Automatic Transaxle - Unit Repair (Section 7A2B) of the 1991 - 93 Geo Storm Service Manuals (ST371-91, ST371-92 and ST371-93, respectively).

REVERSE CLUTCH

Measure:

------- - Clearance between the reverse clutch retaining plate and the snap ring using a feeler gage. Standard clearance is 0.5 to 1.2 mm (0.020 to 0.047-inch). If the clearance is outside these parameters, replace the retaining plate with the appropriate size plate.

HIGH CLUTCH

Measure:

------- - Clearance between the high clutch retaining plate and the snap ring using a feeler gage. The standard clearance is 1.8 to 2.8 mm (0.071 to 0.11 0-inch). If the clearance is outside of these parameters, replace the retaining plate with an appropriate size plate.

FORWARD CLUTCH AND OVERRUN CLUTCH

Measure:

------- - Clearance between the overrun clutch retaining plate and the over-run clutch snap ring using a feeler gage. The standard clearance is 1.0 to 2.0 mm (0.039 to 0.079-inch). If the clearance is outside of these parameters, replace the overrun clutch retaining plate with an appropriate size plate.

- Clearance between the forward clutch retaining plate and the forward clutch snap ring using a feeler gage. The standard clearance is 0.45 to 2.25 mm (0.018 to 0.099-inch). If the clearance is outside of these parameters, replace the forward clutch retaining plate with an appropriate size plate.

LOW AND REVERSE BRAKE

Measure:

------- - Clearance between the low-reverse clutch retaining plate and the spacer using a feeler gage. The standard clearance is 1.1 to 2.9 mm (0.043 to 0.114-inch). If the clearance is outside of these parameters, replace the retaining plate with an appropriate size plate.

DIFFERENTIAL CASE

Measure:

------- - Differential gear backlash between the side gear and the pinion gear using a J 8001 dial indicator. If the backlash is greater than 0.3 mm (0.19-inch) replace the side gear thrust washers with an appropriate size washer.

0.765 mm (0.0301-inch) 0.820 mm (0.0323-inch) 0.880 mm (0.0346-inch) 0.940 mm (0.0370-inch)

OIL PUMP - TO - HIGH CLUTCH SHIM ADJUSTMENT

Step number 3 on Page 7A1-2-40 of the 1991 Geo Storm Service Manual and step number 3 on Page 7A2B-51 of the 1992 and 1993 Geo Storm Service Manuals should read:

3. Place the J 35284-1 bridge and leg assembly, the J 35284-19 bridge extension with J35284-4 gage cylinder and the J35284-32 high clutch gage pin on the transaxle case.

THE GASKET SHOULD NOT BE INSTALLED WHEN PERFORMING THIS ADJUSTMENT.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.