A/T - No Reverse Tip

TSB 89 - 12 (Apr)

SUBJECT: RENAULT MB1

NO REVERSE




On the Renault MB1 automatic transmission, the snap ring that holds the sprag in place (See Figure 1) has much more tension than the snap ring holding the F2 clutch pack (See Figure 2).

These two snap rings are so close in thickness and dimension that they are easy to switch. If the snap ring for the F2 clutch pack is installed on the sprag, the snap ring can blow off, letting the sprag assembly move out of position. This can cause a no-reverse condition. In some cases it has broken the tip off the speed sensor and the transmission may have second or third gear only, with a no-reverse condition.

If Manual Low can be selected, check first gear engine braking to verify an inoperative sprag assembly.