EMC 7075-T6 Aluminum Insert

EMC Modified Left Case

                             Primary Crankshaft Timken Bearing

Anytime we make the motor perform more than design limits we expect failures.  In the case of the crankcase, this is surely true.  Many  failures have been reported on the primary side roller bearing failure.  I have a motor in hand that was sold as a 103 motor by H/D.  This motor had multiple factures of the retainer clip, and the roller bearing outer race.   Parts of this retainer ring broke off and jammed the balancer rotor and broke the balancer chain.

EMC has designed and tested a solution which is in the above photos.  The left case is machined with threads at a 3 deg taper.  Then a super strong 7075-T6 alum billet is machined.  Green bearing Loctite is applied to this ring.  Finally we screw the ring into the left case with 200 foot pounds of torque.

Primary roller bearing failure causing the balancer to shatter may cause catastrophic bottom failure.   If you have an EMC modified twin cam motor that has a bottom end failure of this nature, your motor is not  covered by the EMC motor warranty!

Review the factory procedures as outlined in the H-D Service Manual for your motorcycle. Be careful to follow all warnings and cautions found in the Service Manual. 

This modification was not done by EMC  - Left crankcase split after 5 minutes on the dyno. Oil seeping from the case.

Steel sleeve for Timken Bearing was Inserted into the Crankcase and held by two set screws.

Beyond Repair - Only Choice is to Order a new case from H/D and install the EMC 3 deg tapered thread sleeve.