• 19mm (1/2"-drive or bigger) socket
  • 1/2"-drive (or bigger) breaker bar or air impact gun

  • Labor:

    The stock oil thermowax bypass pellet has been known to fail by not extending it's "tip" when the oil temps warm up.  The oil thermo pellet was designed to bypass oil flow to the rotor and stationary gear bearings so the engine warm-up is faster and to reduce emissions.  IMO, this is the most stupidest idea to be preventing oil flow to internal bearings just to accelerate engine warm-up and reduce emissions!  (Prior to 1986, the 1st generation RX-7's never had this oil thermo pellet.)

    What are signs of a failed oil thermo pellet?  Oil pressure is slightly lower than normal.  Stock oil pressure at idle should be about 10psi to 20psi.  High RPM oil pressure at 3,000RPM+ should be around 60psi to 70psi.  A failed oil thermo pellet would cause lower oil pressure by about 10psi or more.

    Procedure to remove front eccentric shaft bolt:
    1) Remove stock viscous fan and fan shroud
    2) You should be able to access the 19mm bolt head in the middle of the main pulley.
    3) With the 19mm socket and breaker bar, lay the breaker bar on the driver's side sub frame next to the battery - wrap the breaker bar with a rag to prevent too much damage.  If you have an air impact gun, you can gun if off at this point.
    4) Close hood for safety
    5) Remove top two fuses in engine bay to disable ECU and prevent the engine from firing up
    6) Crank the engine for just a SPLIT-SECOND - this should loosen the bolt enough for you to manually remove the rest of the way.

    Oil Thermo Bypass Pellet Shim Procedure
    Oil thermo bypass pellet assembly
    Assembly as extracted out of the front of the eccentric shaft.
    Oil thermo bypass pellet assembly separated into it's three components
    Left:  Front eccentric bolt
    Notice large copper crush washer and rubber o-ring at tip of bolt which needs to be inspected and replaced if needed.

    Middle:  Oil thermo bypass pellet itself.

    Right:  Retaining spring.
    Oil thermo bypass pellet shown in retracted and extended positions
    Left:  Retracted position - when oil is cold.  This is the position it stays in when it fails.

    Right:  Extended position - when oil is hot.
    The oil thermo bypass pellet extends to plug the bypass oil passage in the front of the eccentric shaft.  This bypasses oil flowing to the rotor bearings until oil is warmed up.
    Oil thermo bypass pellet with washers
    You'll need to shim the oil thermo pellet to at a minimum of 6.0mm.  Washers vary in thickness, so make sure you measure them.  In this case, five M7 metric washer used to shim oil thermo bypass pellet on the right.
    Five M7 metric washers positioned on the oil thermo bypass pellet
    Oil thermo bypass pellet assembled with bolt and spring

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