M/T - 3rd to 4th Gear Selector Shaft Modification

GROUP 23
Manual Transmission

Bulletin Number
23 01 90

Woodcliff Lake, NJ
February 1990
Service Engineering

SUBJECT:
Transmission Adjustment

MODELS:
M5, M6 (with Getrag 280/5.50 transmission)

Complaint:
Transmission shifting from 3rd or 4th gear during deceleration.

Solution:
Modify the 3-4 selector shaft detent spring pressure.

- Remove exhaust system and heat shield.

- Remove drive shaft assembly.

- Support transmission with a suitable device (transmission jack, stilt, etc.).

- Detach transmission crossmember and lower transmission to gain access to the rear transmission case.

- Remove detent spring retainer plate.

Caution:
Plate under spring pressure.





- Remove the standard 3-4 selector shaft detent spring (center position, (See Illustration).

- Install a new detent spring (P/N 23 31 1 224 243) which has a revised spring rate and length.

Note:
Standard spring length = 20.5 mm
New spring length = 15.9 mm

- Using standard flat washers with 9 mm outside diameter create a "spacer"of 1.4 mm.

- Coat the washers with grease and place the 1.4 mm spacer in the detent spring retainer plate center position (See Illustration).

- Reinstall the detent spring retainer plate using care to seal the mating surfaces.

- Reinstall the transmission crossmember, drive shaft assembly and the exhaust system.





Warranty Information:
This repair is reimbursable under the terms and conditions of the BMW 3 Year/36,000 Mile New Car Limited Warranty.

Labor Allowance Information:
Initial time studies indicate that this repair can be performed in under 2 hours. Since no specific labor operation presently exists, work time is specified as the labor allowance. However, the total work time claimed should not exceed 24 FRU and, also, it must agree with the repair order punch time.