BELLOWS EXPANDER 91-45497A1

Function and technical context

The 91-45497A1 Bellows Expander is a specialized shop tool designed to facilitate the removal and reassembly of the transmission and cooling system bellows on Alpha One and Bravo series MerCruiser engines. It works by expanding the bellows in a controlled manner—whether the tail bellows or the transom bellows—to separate it from its seat without causing tears or deformations in the rubber, a piece that is expensive to replace if it deteriorates due to a bad procedure. Its use is essential in interventions on the conical group, the tail seal and the internal components of the transom, guaranteeing that the tightness of the system remains intact after the work. Directly replaces part number GLM90360 and is compatible with current Mercury part numbers 8M0096108 and 46-8M0096108.

When to use this tool?

This tool should be used whenever removing or installing the tail bellows on MerCruiser Alpha One Gen. II, Bravo One, Two, Three engines and their high-performance variants, especially when symptoms such as water ingress into the conical group oil, visibly cracked or hardened bellows are detected, or when performing periodic tail oil maintenance—recommended every season or every 100 hours of sailing. Forcing the bellows without the proper expander causes breakage that results in contamination of the oil with salt water, which can destroy the bevel gears within a few hours of use; Using the correct tool for each intervention is the most economical way to protect an expensive repair.

Mercury/MerCruiser

Equivalent manufacturer part numbers