Evo Cam Bearing Replacement

Evo cam bearing is in our sights. Mike has already disassembled the cam compartment on our Evo motor. The crankshaft runout on this pinion side has been measured with a dial indicator and was found to be well within the factory specifications.

Next up, Mike will be removing and replacing the Evo cam bearing. Replacement of this Evo cam bearing is not something to be taken lightly. If the bearing is damaged upon removal or during installation, there is the risk of having one or more of the hardened roller bearings fall into the crankcase. If this happens, you will inevitably be moving towards pulling the crankcase out of the frame and splitting the cases in order to retrieve the missing roller bearings. At this point, the tapered main bearings and the large pinion side bearing should also be replaced.

For this reason, it is important to inspect the original Evo cam bearing prior to removal and after removal. If it is determined that a roller bearing is missing from the bearing cage but that roller bearing is found and recovered from the cam compartment, you can move forward with confidence that the hardened debris is not missing inside the bottom of the crankcase.

Mike uses a specialty tool from JIMS Tools to both remove and install the Evo cam bearings. While removing, Mike feels for a proper tolerance fit. If the bearing pulls out too easily, it may be something that should be looked into further. After the original bearing is removed and pulled off of the specialty tool, it is inspected for damage. Mike applies a light coating of clean motor oil over the roller bearings and onto the outer cage of the new Evo cam bearing. The rolled edge of the bearing should go into the case first. If both edges look the same, the ID numbers on the bearing cage should be pressed against (by the tool).

Again, while pressing the new Evo cam bearing in, Mike feels for proper tolerance fitment.

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