Differences

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--- techtalk:evo:engmech04j [2021/07/06 23:44]
hippysmack [For bushing installation]
+++ techtalk:evo:engmech04j [2021/07/08 00:15]
hippysmack [Check the shaft in bushing clearance]
@@ Line 80: / Line 80: @@
   - 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.
-    * 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 bushing, it 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|}}|
@@ Line 125: / Line 128: @@
 ==== 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, \\
 You can use a welding tip cleaner or other small wire to poke down this hole to clean or verify the hole is clear. \\
@@ Line 145: / Line 146: @@
 |{{: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 ======
-**Note**: The bushing reamer (94804-57) has right hand blades. Always turn it to the right (clockwise) when installing, reaming or removing it from the bushings. \\
+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)) \\
 If the rocker arm pads or the pushrod cups are worn badly, it'd probably be best to just replace the arms instead. \\
-New rocker arms come with the bushings installed and sized. \\
+New rocker arms come with the bushings installed and pre-sized. \\
 Specs: Shaft in bushing (loose) \\
@@ Line 157: / Line 159: @@
 It's not common to have to replace the rocker arm bushings. ((Scuba10jdl of the XLFORUM http://xlforum.net/forums/showthread.php?t=1712024&highlight=rocker+arm+bushings)) \\
 Unless you run them dry or put high lift cams in causing them to hit the boxes, you shouldn't have an issue with them. \\
 The bushings may wear eventually, but that should be well in to the 100k territory. \\
-I don't know anyone who has worn one out.
 As far as rocker arm bushings, where they're made isn't nearly as important as having them installed and fitted correctly. ((rivethog of the XLFORUM http://xlforum.net/forums/showthread.php?t=1890998&highlight=rocker+arm+bushings)) \\
 Replace the rocker arm bushings one at a time. \\
@@ Line 171: / Line 171: @@
 Then you'll have wasted a tap and possibly destroyed the threads you just cut. \\
-  * Basic tool list:
+  * **Basic tool list**:
     * (1) 9/16"x18 tapered thread tap
     * (1) 9/16"x18x1" grade 8 bolt (3/4" to 1-1/2" length will work)
@@ Line 183: / Line 183: @@
 Or you can an arbor press or shop press to pull them in also. \\
-  * Nut / Bolt Press:
+  * **Nut / Bolt Press**:
     * (1) 1/2"x13x5" grade 8 bolt
     * (2) 1/2" grade 8 washers
     * (1) 1/2" grade 8 nut
     * (1) 3/4" box end wrench
-  * Arbor Press or Shop Press:
+  * **Arbor Press or Shop Press**:
-  * A standard bench vise isn't the best idea, but; \\ Technically (if your vise opens wide enough) you could make a arbor button that will fit the bushing with a stop shoulder, could be any length. ((bustert of the XLFORUM http://xlforum.net/forums/showthread.php?t=2072192&page=3)) \\ That way, the ID is protected from the threads and with the stepped shoulder, press it home until it stops. \\ The arbor button could be a right sized bolt with a long shank with the threads cut off. This would negate the need for turning one on a lathe.
+    * You can make an arbor button that will fit the bushing with a stop shoulder, could be any length. ((bustert of the XLFORUM http://xlforum.net/forums/showthread.php?t=2072192&page=3)) \\ That way, the ID is protected from the threads and with the stepped shoulder, press it home until it stops. \\ The arbor button could be a right sized bolt with a long shank with the threads cut off. This would negate the need for turning one on a lathe.
+  * **Using a Bench Vise**:
+    * A standard bench vise isn't the best idea, but if your vise opens wide enough, you could try it as a press with an arbor button as mentioned above. ((bustert of the XLFORUM http://xlforum.net/forums/showthread.php?t=2072192&page=3)) \\
     * However, keep in mind that most bench vises do not have a dedicated flush pull though. ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?t=2072192&page=3)) \\ The jaws will pull closer together on the opposite side of where the piece is clamped. \\ So the rocker arm would need to be placed in the center of the vise to help ensure a center pull on the bushing to keep it from binding / distorting. \\ Then pull the bushing in slowly checking for binding as you go. It will get tight once the bushing gets about halfway home.
-==== For bushing reaming/sizing ====
+==== For bushing reaming / sizing ====
-  * Rocker arm bushing reamer (94804-57)
+  * **Using the JIMS rocker arm bushing reamer**:
-  * (1) 1/2"x12" wooden dowel
+    * 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.
-  * A few small pieces of sandpaper:
+  * **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.
-    * 60 grit, 220 grit, 400 grit, 1500 would be good to have on hand depending on how the reaming goes.
+    * This type reamer is best used in a milling machine.
+    * It can be used to hand ream but only if you have a centering fixture like a sleeve bushing inserted in the opposite end of the rocker arm. \\ The hole has to be centered from one bushing thru to the end of the opposite bushing.
+    * It can be used with a hand drill on low speed. Non tapered reamers cut on the chamfered end and center around the cut they just made. \\ If it bites more to one side or the other, especially on the initial cut, the rest of the ream job won't go well. \\ A extra sleeve bushing for the reamer shaft is a must for using this type reamer for these bushings.
+  * **Line Lapping (if necessary)**:
+    * (1) 1/2"x12" wooden dowel
+    * A few small pieces of sandpaper:
+      * 60 grit, 220 grit, 400 grit, 1500 would be good to have on hand depending on how the reaming goes.
 |  "Jims" reamer for the rocker arm bushings. \\ It's referenced to HD part number (94804-57) ((photo by Hippysmack))  |  Other tools ((photo by Hippysmack))  |  Wooden dowel lapping tool ((photo by Hippysmack))  |
@@ Line 269: / Line 277: @@
 |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|}}|
-==== 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)) \\
 That way the existing bushing acts as a guide for the bushing being reamed. \\
@@ Line 282: / Line 290: @@
 **The process**; \\
   - Line ream the bushing using rocker arm bushing reamer (94804-57).
@@ Line 311: / Line 318: @@
 |{{: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)) \\

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