Miata Technical Service Bulletin

Category Applicable Model(s) Subject
Bulletin No. 004/92
Issued 7/7/92
J MX-5 Miata
RX-7 Non-Turbo
Hard shift to 2nd gear after cold start


Hard shifting into second gear before the vehicle has had sufficient time to warm up may be caused by insufficient clearance between 2nd gear synchronizer ring and the 1-2 clutch hub. Design changes have been made to the 2nd gear synchronizer ring and clutch hub sleeve to correct this problem since April 1, 1991.

If you experience hard shifting into 2nd gear after a cold start with an RX-7 (non-turbo) or Miata produced prior to April 1, 1991, replace the 2nd gear synchronizer ring and 1-2 clutch sleeve (or 1-2 clutch hub set) with redesigned ones. Refer to section J of the workshop manual for installation procedures.

Vins of Production Change

MX-5 Miata JM1NA351*M*232720 April 1, 1991
RX-7 (Non-Turbo) JM1FC3***M0906971 April 1, 1991

 Parts Information

Part Number Description Quantity Interchangeability
New Old
M502 17 265C M502 17 265B 2nd Synchronizer Ring 1 New -> Old
M503 17 262A M503 17 262 1-2 Clutch Hub Sleeve 1 New -> Old
M505 17 260B M505 17 260A 1-2 Clutch Hub Set 1 New -> Old

Warranty Information

(Applies to vehicles covered under warranty.)

Warranty Type Code: A
Customer Complaint Code: 99
Damage Code: 99
Part No. of Main Cause: M502 17 265C (Qty. 1)
Related Parts: M503 17 262A
M505 17 260B
  Miata RX-7
Operation No: J0315XRX J0315ARX
Labor Hour: 5.2 Hrs. 5.1 Hrs.

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