Originally Posted by boogaloodude

I always use the proper tool to set inner cam bearings. It's not complicated, but it's also possible to damage the bearings if they're installed incorrectly. Lots of guys have installed their inner cam bearings by tapping them into place with no apparant problems, and they will tell you it's an acceptable risk. It's up to you to decide whether or not the risk is worth the cost savings, but you should have the whole story so you can make an informed decision.

Bearing install tips from the Timken website:

Proper installation is critical if you want a drawn cup needle bearing to perform correctly in an application. Highlighted below are general guidelines that apply when installing a drawn cup needle roller bearing.

• A drawn cup bearing must be pressed into its housing.
• An installation tool must be used in conjunction with a standard press. The installation tool should:
- Have a back angle, around 15 degrees, on the shoulder used to apply the press force to the bearing outer ring.
- Have a pilot to center and guide the bearing.
- Have a ball detent on the pilot if the bearing being installed is a full complement type.
- Be on the same axis as the housing bore.
- Be made to specific dimensions, based on the equipment manufacturer’s recommendations.

• The bearing must not be hammered into its housing even if a proper installation tool is being used.
• The bearing should not be pressed tightly against a shoulder in the housing. If it is necessary to use a shouldered housing, the depth of the housing bore must be sufficient to ensure that the housing shoulder fillet and shoulder face clear the bearing.

If these guidelines are not followed, the bearing may be damaged during installation.