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techtalk:evo:engmech04j [2021/07/07 02:11]
hippysmack [Rocker Arm Bushing Replacement]
techtalk:evo:engmech04j [2021/07/08 00:15]
hippysmack [Check the shaft in bushing clearance]
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   - Measure and record the I.D of the rocker arm bushing with a telescoping bore gauge and caliper.   - Measure and record the I.D of the rocker arm bushing with a telescoping bore gauge and caliper.
   - Subtract the shaft dia. from the bushing I.D. and match that number against the wear limit specs.   - Subtract the shaft dia. from the bushing I.D. and match that number against the wear limit specs.
-    * If the bushing is at or past the service wear limit, ​proceed ​to "​replacing ​the bushings" as in below+    ​* If the bushing is within service limit, install the rocker arm as is. 
 +    ​* If the bushing is at or past the service wear limit
 +      * Proceed to [[techtalk:​evo:​engmech04j#​rocker_arm_bushing_replacement|Replacing the Rocker Arm Bushings]] below. 
 +      * If you choose not to replace the bushingit is advised ​to replace ​the entire rocker arm. \\ New rocker arms come with new pre-sized ​bushings.
  
 |{{:​techtalk:​evo:​engmech:​mic_the_rocker_arm_shaft_2_by_hippysmack.jpg?​direct&​300|}}|{{:​techtalk:​evo:​engmech:​mic_the_rocker_arm_bushing_bore_1_by_hippysmack.jpg?​direct&​300|}}|{{:​techtalk:​evo:​engmech:​mic_the_rocker_arm_bushing_bore_2_by_hippysmack.jpg?​direct&​300|}}| |{{:​techtalk:​evo:​engmech:​mic_the_rocker_arm_shaft_2_by_hippysmack.jpg?​direct&​300|}}|{{:​techtalk:​evo:​engmech:​mic_the_rocker_arm_bushing_bore_1_by_hippysmack.jpg?​direct&​300|}}|{{:​techtalk:​evo:​engmech:​mic_the_rocker_arm_bushing_bore_2_by_hippysmack.jpg?​direct&​300|}}|
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 ==== Check the valve oiler hole in the rocker arm ==== ==== Check the valve oiler hole in the rocker arm ====
-The valve side arm has one tiny little hole that the intake rockers don't have. ((DirtyCory of the XLFORUM http://​xlforum.net/​forums/​showpost.php?​p=3945019&​postcount=317)) \\ +The valve side of the rocker arms have one tiny little hole that sprays oil on the valve for extra cooling. \\
-This tiny little hole is for extra oiling for cooling ​the valve(s). \\ +
 While you have the rocker arms out, \\ While you have the rocker arms out, \\
 You can use a welding tip cleaner or other small wire to poke down this hole to clean or verify the hole is clear. \\ You can use a welding tip cleaner or other small wire to poke down this hole to clean or verify the hole is clear. \\
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 |{{:​techtalk:​evo:​engmech:​rocker_arm_inspection_1_by_hippysmack.jpg?​direct&​300|}}|{{:​techtalk:​evo:​engmech:​rocker_arm_inspection_2_by_hippysmack.jpg?​direct&​300|}}|{{:​techtalk:​evo:​engmech:​rocker_arm_inspection_3_by_hippysmack.jpg?​direct&​300|}}| |{{:​techtalk:​evo:​engmech:​rocker_arm_inspection_1_by_hippysmack.jpg?​direct&​300|}}|{{:​techtalk:​evo:​engmech:​rocker_arm_inspection_2_by_hippysmack.jpg?​direct&​300|}}|{{:​techtalk:​evo:​engmech:​rocker_arm_inspection_3_by_hippysmack.jpg?​direct&​300|}}|
 ====== Rocker Arm Bushing Replacement ====== ====== Rocker Arm Bushing Replacement ======
 +This procedure is ONLY needed IF you want to replace the bushings but not the rocker arms. \\
 +New rocker arms come with new bushings that have already been properly sized for the rocker arm shafts. \\
 + 
 A helpful suggestion is to mic the bushings closely and several times to be sure you need to before replacing them. ((Hippysmack of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=2072192)) \\ A helpful suggestion is to mic the bushings closely and several times to be sure you need to before replacing them. ((Hippysmack of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=2072192)) \\
 If the rocker arm pads or the pushrod cups are worn badly, it'd probably be best to just replace the arms instead. \\ If the rocker arm pads or the pushrod cups are worn badly, it'd probably be best to just replace the arms instead. \\
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 ==== For bushing reaming / sizing ==== ==== For bushing reaming / sizing ====
   * **Using the JIMS rocker arm bushing reamer**:   * **Using the JIMS rocker arm bushing reamer**:
-    * JIMS reamer (94804-57) is quite expensive at a current average of $267. But it works very well. \\ It is used with a hand tap wrench or socket wrench. ​+    * JIMS reamer (94804-57) is quite expensive at a current average of $267. But it works very well. \\ It is used with a hand tap wrench or socket wrench. \\ **Note**: This reamer has left hand spiral blades (right hand cut). Always turn it to the right (clockwise) when installing, reaming or removing it from the bushings. \\ Never turn it to the left while in use.
   * **Using a Chucking reamer**: \\ These are less expensive but there are considerations for using one. \\ This is a non tapered reamer with a small chamfer on the end and is shorter than a tapered reamer.   * **Using a Chucking reamer**: \\ These are less expensive but there are considerations for using one. \\ This is a non tapered reamer with a small chamfer on the end and is shorter than a tapered reamer.
     * This type reamer is best used in a milling machine.     * This type reamer is best used in a milling machine.
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 |If needed, the end of the bushing can be filed down flush to the rocker arm. Place a straightedge across the assembly to ensure it's flat end to end. \\ The file will cut down the bushing before harming the hardened rocker arm. ((photos by Hippysmack))||| |If needed, the end of the bushing can be filed down flush to the rocker arm. Place a straightedge across the assembly to ensure it's flat end to end. \\ The file will cut down the bushing before harming the hardened rocker arm. ((photos by Hippysmack))|||
 |{{:​techtalk:​evo:​engmech:​replacing_rocker_arm_bushings_44_by_hippysmack.jpg?​direct&​300|}}|{{:​techtalk:​evo:​engmech:​replacing_rocker_arm_bushings_45_by_hippysmack.jpg?​direct&​300|}}|{{:​techtalk:​evo:​engmech:​replacing_rocker_arm_bushings_46_by_hippysmack.jpg?​direct&​300|}}| |{{:​techtalk:​evo:​engmech:​replacing_rocker_arm_bushings_44_by_hippysmack.jpg?​direct&​300|}}|{{:​techtalk:​evo:​engmech:​replacing_rocker_arm_bushings_45_by_hippysmack.jpg?​direct&​300|}}|{{:​techtalk:​evo:​engmech:​replacing_rocker_arm_bushings_46_by_hippysmack.jpg?​direct&​300|}}|
-==== Ream and Lap the New Bushing ====+==== Ream the New Bushing ​to Size ====
 The proper way to ream rocker shaft bushing'​s is to come in from the opposite bushing with the reamer. ((brucstoudt of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​p=5189428&​highlight=rocker+arm+bushings#​post5189428)) \\ The proper way to ream rocker shaft bushing'​s is to come in from the opposite bushing with the reamer. ((brucstoudt of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​p=5189428&​highlight=rocker+arm+bushings#​post5189428)) \\
 That way the existing bushing acts as a guide for the bushing being reamed. \\ That way the existing bushing acts as a guide for the bushing being reamed. \\
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 **The process**; \\ **The process**; \\
- 
  
   - Line ream the bushing using rocker arm bushing reamer (94804-57).   - Line ream the bushing using rocker arm bushing reamer (94804-57).
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 |{{:​techtalk:​evo:​engmech:​replacing_rocker_arm_bushings_56_by_hippysmack.jpg?​direct&​300|}}| |{{:​techtalk:​evo:​engmech:​replacing_rocker_arm_bushings_56_by_hippysmack.jpg?​direct&​300|}}|
  
-=== Line Lapping ​===+==== Lap New Bushing If Needed ​==== 
 +Sometimes a reaming job just doesn'​t quite go as expected or doesn'​t quite give the clearance needed. \\ 
 +If using a same size reamer as the shaft, you can ream the bushing and then lap it to get the desired clearance. \\ 
 +This will yield a tighter clearance than using the next up size reamer. \\ 
 +Lapping is a common practice after reaming. \\
  
 A lapping tool can be made from a 1/2" wooden dowel and a small piece of sandpaper. ((photos by Hippysmack)) \\ A lapping tool can be made from a 1/2" wooden dowel and a small piece of sandpaper. ((photos by Hippysmack)) \\