GM-50910-3A is a new design protector required for RPO code MQE 8L90 transmission models in C/K Trucks. The protector has a slightly larger ID due to a change in the MQE turbine shaft. The tool prevents the solid Teflon seal ID from damage as it is slid over the end of the turbine shaft and into the seal groove.
GM-50910-3A will back-service all 8L90 transmissions and supersedes GM-50910-3. The original GM-50910-1 Seal Sizer and GM-50910-2 Seal Pusher, included in the GM-50910 Seal Installation Kit, are still used with the GM-50910-3A.