Differences

This shows you the differences between two versions of the page.

--- techtalk:evo:engmech01a [2018/05/14 03:15]
hippysmack [Using a Longer Replacement Plug]
+++ techtalk:evo:engmech01a [2018/05/14 03:48]
hippysmack [Pics and App. Dims]
@@ Line 1: / Line 1: @@
 [[:techtalk:menu|{{  :techtalk:gototechnicalmenu.jpg|}}]]
 ====== EVO: Engine Mechanicals - Sub-01A ======
-====== Timing Inspection Hole / Plug Thread Repair ======
+===== 91-03 Timing inspection hole and plug pics and app. dims =====
-  * These are aluminum internal (case) and steel external (plug) threads (5/8"x18 NF straight bolt cut).
-  * It is a common occurrence to damage these threads or for them to being found to be damaged. Whoever threaded the plug in last may have not taken the time to insure proper thread starting before using a wrench to install the plug and cross-threaded them. Over tightening the plug can crack / stretch the threads and thermal expansion can warp and gall them ((hippysmack)). Sometimes the threads get corroded and galled to the point that removing the plug takes the threads out with it. You can't be certain that the threads haven't been galled before you remove the plug. ((wedge of the XLFORUM http://xlforum.net/forums/showthread.php?t=1620575&highlight=timing+inspection+hole)) If you've noticed oil seeping from this plug, the threads are at least suspect.
-|Timing inspection hole on a 98 case (centered between the two \\ cylinders on the right crankcase) ((photo by Hippysmack))|The plug can be removed with a 3/8" hex tool (Allen wrench).|
-|{{:techtalk:evo:engmech:timing_inspection_hole_pic1_by_hippysmack.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_inspection_hole_pic16_by_hippysmack.jpg?direct&400|}}|
-  * Once removed, check the threads on the plug and in the case for damage before trying to re-install the plug. These are straight (not tapered) threads on the plug and in the case. There is no need for the plug to have tapered threads with it having a head on the end. Inspect them closely and,  in the case of warped or damaged threads, first try to repair or 'chase' the them. This will keep you from having to drill into the case if it isn't necessary.
-====== Leaking Oil From the Plug ======
-If your plug is not loose and will tighten up, you may have some warped threads that aren't allowing the flat machined surface on the back of the plug head to seal against the flat machined outer surface of the case. Over tightening from here will damage the threads even more. ((Hippysmack))
-  * Try pulling the plug, clean the threads and use some anti-seize on them. The anti-seize should seal up the threads as long as the crank case isn't building pressure and causing it to push some seepage out. ((wedge of the XLFORUM http://xlforum.net/forums/showthread.php?t=1958781&highlight=timing+hole+plug)) Teflon tape can also be used on the threads to prevent leakage.
-====== Using a Longer Replacement Plug ======
-You can purchase a 5/8-18 oil drain plug from many auto parts stores.
-|The head may be larger than the original but it can be ground to fit with a bench grinder. ((photos by Jordan 1200 of the XLFORUM http://xlforum.net/forums/showthread.php?t=2068069&page=9))|||
-|{{:techtalk:evo:engmech:timing_plug_fix_1_by_jordan1200.jpg?direct&200|}}|{{:techtalk:evo:engmech:timing_plug_fix_2_by_jordan1200.jpg?direct&200|}}|{{:techtalk:evo:engmech:timing_plug_fix_5_by_jordan1200.jpg?direct&200|}}|
-  * If the head on the new one is too big to fit into the machined area of the hole, marked one flat of the head with a sharpie marker so you can verify you've made a full rotation while grinding.
-    * Try to stay on the side of the head instead of under the it with nice even pressure while turning the plug against the wheel.
-    * Clean the edge with a wire wheel (with light pressure) making sure there are no burrs or protrusions on the flat backside of the head (your sealing surface). Install the plug and your done.|||
-|Measure the heads on the old and new plug, grind the new one if needed. ((photos by Jordan 1200 of the XLFORUM http://xlforum.net/forums/showthread.php?t=2068069&page=9))|||
-|{{:techtalk:evo:engmech:timing_plug_fix_3_by_jordan1200.jpg?direct&200|}}|{{:techtalk:evo:engmech:timing_plug_fix_4_by_jordan1200.jpg?direct&200|}}|{{:techtalk:evo:engmech:timing_plug_fix_6_by_jordan1200.jpg?direct&200|}}|
-====== Installing the Plug ======
-  * Torque value under factory conditions: torque value 10-15 ft/lbs ((jordan1200 of the XLFORUM http://xlforum.net/forums/showthread.php?t=2068069&page=9)) with a dry plug. However, the torque should be adjusted to suit your 'current conditions'. If you have added thread dressing, Teflon tape or have existing warp-age or damaged threads, lower the torque some (maybe by 1/3 or so).
-  * The threads can strip easily so be careful with it. Clean the threads for both the plug and the hole, thread the plug into the case using fingers only, then snug up to "firm plus a little more". Regarding the "just snug": you have to trust this stuff. Too tight and you got a problem. The plug has fine threads that resist loosening from vibration. "Trust" is the key word.((IronMick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1988386&highlight=timing+hole+plug)) ((IronMick of the XLFORUM http://xlforum.net/forums/showthread.php?t=41695&highlight=timing+hole+plug))
-  * The plug and the case threads are different metals and torque will usually always side towards the metal on the plug. This leaves the aluminum case threads more vulnerable to damage from over-torque.
-  * You should also use anti-seize on the plug threads before installing it to help prevent galling and damage upon removal. ((Hippysmack))
-  * Blue Loctite can also be used to seal the threads ((IronMick)) but it also adds more torque necessary to remove the plug. If you know you already have a certain amount of thread damage (as in when you installed the plug last), increasing torque while removing the plug may add to that damage.
-====== Permanent Thread Repairs  ======
-  * The foregoing is under the assumption the engine is assembled. This would obviously not be as big of an issue with the engine out and the case split. Repairs of the timing inspection hole are much easier for you or most machine shops without the flywheel in the way or concerns of metal shavings getting into the engine.
-===== Chasing the Threads =====
-See also the [[techtalk:ref:notes12|warped or damaged thread repair]] section of the Sportsterpedia.
-  * A tap and a die is normally used to chase the threads in the case and on the plug respectively back to their original shape / cleanliness and usually done with plenty of good cutting oil. \\ However, for this application, fluidity can be detriment to the cause. With the small amount of threads on the plug and the imminent danger of getting cut shavings (swarf) into the engine case thru the timing hole, it is best to use thick lube or even axle grease to lube the tap to chase the case threads. \\ While chasing the threads, your following the existing 'centered' thread pattern. ((Hippysmack http://xlforum.net/forums/showthread.php?t=2068069&page=3)) \\ You only have to run the tap in far enough to clear the length of the plug, not to the end of the case threads. \\
-==== Tools Needed ====
-  * You can generally purchase these at most machinist supply stores online cheaper than you can buy them from motorcycle supply stores 'made for Harleys'.
-  * They do not have to be expensive. They simply have to be the right size and shape for your application.
-|**5/8"x18 NF 'bottoming' hand tap** for the case threads \\ (which is flat on the end without a taper)|**5/8"x18 NF die** for the plug|
-|{{:techtalk:ref:notes:5-8x18_bottoming_tap_by_hippysmack.jpg?direct&400|}}|{{:techtalk:ref:notes:5-8x18_die_by_hippysmack.jpg?direct&400|}}|
-  * **Choosing the right tap**
-    * A bottoming tap only has a very short taper on the end to allow it to get inside the hole. It will immediately cut the threads before it bottoms out into the flywheel. ((Whitewalls of the XLFORUM http://xlforum.net/forums/showthread.php?t=2067088&page=2))
-    * A tapered (not to be confused with tapered thread) or plug style tap has a longer tapered end. The tapered end does not cut any threads and it will bottom out against the flywheel before the threads are finished cutting. It is designed to help you center up in the hole for tapping new threads. If you continue turning from that point, you risk back pressure on the tap which could crack the case. If you aren't planning on doing this again, you could cut off the taper ((iNSaNeSHaNe of the XLFORUM http://xlforum.net/forums/showthread.php?t=2067088&page=3)) (with a Dremil cutting tool) but leave a slight amount of it to allow you to get into the hole before the threads start. But, it's just better to buy the correct tool.
-  * **Choosing the right die**
-  * You can use a standard round or a hex die. Either will do the job and possibly be held in your palm for use. But, if your threads are bad enough to need repairing this way, you probably need to buy the wrench for it.
-    * The round one requires a spanner wrench to hold it for use. Although it can be clamped in a vise, if you have to turn too hard it will just spin out of the vise. Again, it's best to have the tools.
-    * The standard hex die can be clamped into a vise, held by a standard open end wrench or a socket. You can also purchase the die wrench that fits it.
-  * **Tap Wrench**: These come in different sizes so make sure it's correct for a 5/8" tap.
-  * **Die Wrench**: The rounded O.D. die works best with the holder wrench to fit it. Some die and die holders have a different OD depending on the brand.
-  * **Thick lube or grease** is needed to catch and hold the shavings and keep them from flinging through the engine case. You will need to clean the threads after your done repairing them. Using compressed air from the engine out through the hole will not work while using lube since the shavings will cling to it and not be blown out of the hole.
-  * **Optional Items**:
-    * **Panty Hose**: Stuff a small piece (3" - 4" long) of panty hose into the hole prior to any work (between the flywheel and the case while allowing a small amount to be gotten to later with a pick). Make sure the material is not in the way of your work. You wouldn't want to snag it and spin shavings everywhere. The grease on the tap should also help minimize snagging the material. You could also grease the panty hose. When the job is complete grab the panty hose with a hook pick and needle nose pliers (so you don't let go of the panty hose) and pull it out while turning it counterclockwise to help remove the chips from the threads. Any foreign material not already caught up in the threads should be stuck to the panty hose. ((Whitewalls of the XLFORUM http://xlforum.net/forums/showthread.php?t=2067088&page=2)) Pull the material slowly out, so as not to pop any debris off of it into the engine, and it will act as a brush.
-==== Thread Repair ====
-|Start off by cleaning the area outside the plug|Cut a short piece of panty hose app. 3" - 4" long|
-|{{:techtalk:evo:engmech:timing_hole_thread_repair_1_by_hippysmack.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_hole_thread_repair_2_by_hippysmack.jpg?direct&400|}}|
-|Tape the length of threads to repair on the tap using the plug as a \\ guide|The pick is to guide and maneuver the panty hose|
-|{{:techtalk:evo:engmech:timing_hole_thread_repair_3_by_hippysmack.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_hole_thread_repair_4_by_hippysmack.jpg?direct&400|}}|
-|Pack the panty hose beyond the intended repair area|Lube the end of the tap, especially the flutes|
-|{{:techtalk:evo:engmech:timing_hole_thread_repair_5_by_hippysmack.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_hole_thread_repair_6_by_hippysmack.jpg?direct&400|}}|
-|Start the tap by hand. Be sure you catch a few good threads as you \\ turn in order to retain the original straightness and center|Run the tap in all the way to the taped area and then back it out|
-|{{:techtalk:evo:engmech:timing_hole_thread_repair_7_by_hippysmack.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_hole_thread_repair_8_by_hippysmack.jpg?direct&400|}}|
-|Flutes catch and keep the bulk of the shavings|The panty hose keeps small particles out of the engine case. The \\ shavings on the panty hose pictured got there from the tap running \\ into it. Without the panty hose, the shavings would have simply stuck \\ to the flutes in the tap. But it is piece of mind|
-|{{:techtalk:evo:engmech:timing_hole_thread_repair_10_by_hippysmack.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_hole_thread_repair_11_by_hippysmack.jpg?direct&400|}}|
-|Fish the panty hose out with the pick. Once it's peeping out the hole, \\ back it out by turning counterclockwise as you would the plug \\ while pulling to help clear the threads|Shavings cling to the panty hose|
-|{{:techtalk:evo:engmech:timing_hole_thread_repair_12_by_hippysmack.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_hole_thread_repair_13_by_hippysmack.jpg?direct&400|}}|
-|With the threads repaired, they now need to be cleaned up|Run the tap back in by hand. The remaining chips will cling to it|
-|{{:techtalk:evo:engmech:timing_hole_thread_repair_14_by_hippysmack.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_hole_thread_repair_15_by_hippysmack.jpg?direct&400|}}|
-|  Remove the tap, clean it and repeat until your comfortable with the results  ||
-|{{:techtalk:evo:engmech:timing_hole_thread_repair_16_by_hippysmack.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_hole_thread_repair_17_by_hippysmack.jpg?direct&400|}}|
-|  Once satisfied with cleanliness, cut a new piece of panty hose, poke it thru the center of the hole, pack it in as before, \\ grab it with the hook and turn it out counterclockwise  ||
-|{{:techtalk:evo:engmech:timing_hole_thread_repair_18_by_hippysmack.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_hole_thread_repair_19_by_hippysmack.jpg?direct&400|}}|
-|Check for debris and when satisfied, your done with the case threads|  **Before** chasing the threads  |
-|{{:techtalk:evo:engmech:timing_hole_thread_repair_20_by_hippysmack.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_inspection_hole_pic2_by_hippysmack.jpg?direct&400|}}|
-|**After** chasing the threads. Notice the tap did not add any meat back to the threads. It simply straightens the threads (or what's left of them) \\ back to their original condition. Install anti-seize on the plug threads and Teflon tape on the neck (if desired) and install the plug||
-|{{:techtalk:evo:engmech:timing_hole_thread_repair_21_by_hippysmack.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_hole_thread_repair_22_by_hippysmack.jpg?direct&400|}}|
-|It's a good idea to chase the threads on the plug to match the newly refurbished threads in the case. \\ Coat the threads with cutting oil and hand start the plug in the die to insure proper thread alignment||
-|{{:techtalk:evo:engmech:timing_hole_thread_repair_23_by_hippysmack.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_hole_thread_repair_24_by_hippysmack.jpg?direct&400|}}|
-|Run the plug down the die with the wrench and insure the head sits flat against the die. \\ Then all you have to do is clean the debris with brake cleaner or WD-40||
-|{{:techtalk:evo:engmech:timing_hole_thread_repair_25_by_hippysmack.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_hole_thread_repair_26_by_hippysmack.jpg?direct&400|}}|
-|**Before** chasing the threads|**After** chasing the threads|
-|{{:techtalk:evo:engmech:timing_hole_thread_repair_28_by_hippysmack.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_hole_thread_repair_27_by_hippysmack.jpg?direct&400|}}|
-  * If chasing the threads doesn't work or leave enough meat to allow the plug to tighten without stripping, you may have to re-tap the hole with bigger threads and buy an oversized plug.
-===== Pics and App. Dims =====

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