All of our rebuilds include the installation of an extra set of key springs in the 1-2 synchronizer hubs. This allows the keys to put a little more pressure on the blocker rings for smoother high RPM shifting. The 1-2 blockers are under the most abuse in transmissions over any other gear, so more spring pressure helps the blocker synchronize the gear quicker and more accurately. The added springs also disperse the outward pressure to the keys a little more evenly allowing them to do their job more efficiently as well.
