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techtalk:ref:engmech01a [2020/04/28 22:53] hippysmack ↷ Links adapted because of a move operation |
techtalk:ref:engmech01a [2024/01/14 16:27] hippysmack |
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| * These are aluminum internal (case) and steel external (plug) threads (5/8"x18 NF straight bolt cut). | * 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 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. | + | * It is a common occurrence to damage these threads or for them 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 https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/149397-stripped-timing-plug?t=1620575&highlight=timing+inspection+hole)) If you've noticed oil seeping from this plug, the threads are at least suspect. |
| - | * The threads can appear to strip for no apparent reason. The problem with drain and timing plugs are the same. ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1541235&highlight=colony+plug&page=4)) | + | * The threads can appear to strip for no apparent reason. The problem with drain and timing plugs are the same. ((Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/142250-more-ironhead-hate-hate-hate/page4?t=1541235&highlight=colony+plug&page=4)) |
| - | * Common occurrences include: ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1541235&highlight=colony+plug&page=4)) | + | * Common occurrences include: ((Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/142250-more-ironhead-hate-hate-hate/page4?t=1541235&highlight=colony+plug&page=4)) |
| * No problems the last time the plug was installed. | * No problems the last time the plug was installed. | ||
| * No problems when the plug was pulled out last. | * No problems when the plug was pulled out last. | ||
| * But when trying to re-install the plug and with little to no torque, the threads did strip. | * But when trying to re-install the plug and with little to no torque, the threads did strip. | ||
| - | * You may have had it out 100 times before and can’t understand what happened now. ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1541235&highlight=colony+plug&page=4)) | + | * You may have had it out 100 times before and can’t understand what happened now. ((Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/142250-more-ironhead-hate-hate-hate/page4?t=1541235&highlight=colony+plug&page=4)) |
| **Case in Point**: | **Case in Point**: | ||
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| * Below is a case drain (left) and a Colony acorn style timing plug (right). | * Below is a case drain (left) and a Colony acorn style timing plug (right). | ||
| - | |See this undercut unthreaded area? \\ All oil plugs are made like this in Milwaukee. ((Photo by Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1541235&highlight=colony+plug&page=4))| | + | |See this undercut unthreaded area? \\ All oil plugs are made like this in Milwaukee. ((Photo by Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/142250-more-ironhead-hate-hate-hate/page4?t=1541235&highlight=colony+plug&page=4))| |
| |{{:techtalk:ref:engmech:case_drain_and_timing_plug_by_dr_dick.jpg?direct&400|}}| | |{{:techtalk:ref:engmech:case_drain_and_timing_plug_by_dr_dick.jpg?direct&400|}}| | ||
| * If there was no undercut, the threads would have incomplete form next to the underside of head. These incomplete threads wouldn’t allow the flat sealing face of the plug to contact the case before the threads were bound up in the tapped hole. So, the malformed threads get cut away by the undercut. The (necessary) undercut is where the problem comes from. The tapped threads in the case run the length of the hole except that there is a (one thread) counter-bore in the front of the case. | * If there was no undercut, the threads would have incomplete form next to the underside of head. These incomplete threads wouldn’t allow the flat sealing face of the plug to contact the case before the threads were bound up in the tapped hole. So, the malformed threads get cut away by the undercut. The (necessary) undercut is where the problem comes from. The tapped threads in the case run the length of the hole except that there is a (one thread) counter-bore in the front of the case. | ||
| - | * In both positions, when the plug gets put into the hole (hand tight) to the sealing surface, there are a few aluminum threads that end up in the undercut of the plug. The plug thread in this area doesn’t have a mating thread when you tighten the plug. It is unsupported. ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1541235&highlight=colony+plug&page=4)) | + | * In both positions, when the plug gets put into the hole (hand tight) to the sealing surface, there are a few aluminum threads that end up in the undercut of the plug. The plug thread in this area doesn’t have a mating thread when you tighten the plug. It is unsupported. ((Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/142250-more-ironhead-hate-hate-hate/page4?t=1541235&highlight=colony+plug&page=4)) |
| - | * The aluminum threads above the undercut do mate to the plug. Then, you put the wrench to it. Under the tightening torque, the aluminum female threads (that are in contact with the male plug threads, above the undercut) get slightly deformed. The aluminum threads, in contact with the plug, get yanked towards the aluminum threads that are just hanging free in the undercut. This creates a sort of cross-threaded condition in the case. A deformed thread just above a non-deformed thread that lives in the undercut. At this point the plug is tight, as in (the last time you tightened it). ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1541235&highlight=colony+plug&page=4)) | + | * The aluminum threads above the undercut do mate to the plug. Then, you put the wrench to it. Under the tightening torque, the aluminum female threads (that are in contact with the male plug threads, above the undercut) get slightly deformed. The aluminum threads, in contact with the plug, get yanked towards the aluminum threads that are just hanging free in the undercut. This creates a sort of cross-threaded condition in the case. A deformed thread just above a non-deformed thread that lives in the undercut. At this point the plug is tight, as in (the last time you tightened it). ((Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/142250-more-ironhead-hate-hate-hate/page4?t=1541235&highlight=colony+plug&page=4)) |
| - | * The next time you remove the plug, (this time) something is present that was too subtle to notice when you break the plug free. It turns freely out about 1/8 turn and then gets too tight to remove by hand so you put the wrench on it and spin the plug out. ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1541235&highlight=colony+plug&page=4)) | + | * The next time you remove the plug, (this time) something is present that was too subtle to notice when you break the plug free. It turns freely out about 1/8 turn and then gets too tight to remove by hand so you put the wrench on it and spin the plug out. ((Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/142250-more-ironhead-hate-hate-hate/page4?t=1541235&highlight=colony+plug&page=4)) |
| - | * It’s right here that the stripping has begun. It got tight because the plug was forcing the deformed female threads back into sync with the non-deformed female threads that live in the undercut. So, the deformed threads get flexed back by the undercut threads as they need to get back in sync for the plug to unscrew. This force of synchronization flexes the undercut threads also. Flexing a piece of cast aluminum back and forth will cause it to break or let loose. ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1541235&highlight=colony+plug&page=4)) | + | * It’s right here that the stripping has begun. It got tight because the plug was forcing the deformed female threads back into sync with the non-deformed female threads that live in the undercut. So, the deformed threads get flexed back by the undercut threads as they need to get back in sync for the plug to unscrew. This force of synchronization flexes the undercut threads also. Flexing a piece of cast aluminum back and forth will cause it to break or let loose. ((Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/142250-more-ironhead-hate-hate-hate/page4?t=1541235&highlight=colony+plug&page=4)) |
| - | * So, it’s not necessarily the design of the oil plug that causes the damage but more of the way the wrenching gets done over the years. Because the damage gets done on the previous in / out cycle, it gets hidden by time the next fatal in / out happens. That’s why it seems to strip out of the clear blue sky. ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1541235&highlight=colony+plug&page=4)) | + | * So, it’s not necessarily the design of the oil plug that causes the damage but more of the way the wrenching gets done over the years. Because the damage gets done on the previous in / out cycle, it gets hidden by time the next fatal in / out happens. That’s why it seems to strip out of the clear blue sky. ((Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/142250-more-ironhead-hate-hate-hate/page4?t=1541235&highlight=colony+plug&page=4)) |
| - | + | |Timing inspection hole location on a pre-91 engine case \\ (centered between the two cylinders on the left crankcase) ((photo by trafetto of the XLFORUM https://www.xlforum.net/showthread.php?|t=1958781&highlight=timing+hole+plug))|Timing inspection hole location on a 91-03 engine case \\ (centered between the two cylinders on the right crankcase) ((photo by Hippysmack))| | |
| - | + | ||
| - | |Timing inspection hole location on a pre-91 engine case \\ (centered between the two cylinders on the left crankcase) ((photo by trafetto of the XLFORUM http://xlforum.net/forums/showthread.php?|t=1958781&highlight=timing+hole+plug))|Timing inspection hole location on a 91-03 engine case \\ (centered between the two cylinders on the right crankcase) ((photo by Hippysmack))| | + | |
| |{{:techtalk:ref:engmech:1989_timing_hole_plug_by_trafetto.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_inspection_hole_pic1_by_hippysmack.jpg?direct&400|}}| | |{{:techtalk:ref:engmech:1989_timing_hole_plug_by_trafetto.jpg?direct&400|}}|{{:techtalk:evo:engmech:timing_inspection_hole_pic1_by_hippysmack.jpg?direct&400|}}| | ||
| Line 43: | Line 41: | ||
| ===== Temporary Repair Options ===== | ===== Temporary Repair Options ===== | ||
| - | In an emergency or as patch until you can have a permanent solution done, here are some possible ideas in the Sportsterpedia to keep you riding ([[techtalk:ref:engmech01d#drain_plug_sealing_and_temporary_fixes|Drain Plug Sealing and Temporary Fixes]]). A temporary repair is just that. It may blow out at any time. It's best to have a spare with you in case the current temporary fix blows out, especially if your away from home. ((RigidIronhead of the XLFORUM http://xlforum.net/forums/showthread.php?t=1541235&highlight=colony+plug&page=2)) | + | In an emergency or as patch until you can have a permanent solution done, here are some possible ideas in the Sportsterpedia to keep you riding ([[techtalk:ref:engmech01d#drain_plug_sealing_and_temporary_fixes|Drain Plug Sealing and Temporary Fixes]]). A temporary repair is just that. It may blow out at any time. It's best to have a spare with you in case the current temporary fix blows out, especially if your away from home. ((RigidIronhead of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/142250-more-ironhead-hate-hate-hate/page2?t=1541235&highlight=colony+plug&page=2)) |
| ====== Installing the Plug ====== | ====== Installing the Plug ====== | ||
| - | * **Torque value**: 10-15 ft. Lbs. (14-21 Nm) on a dry plug with good threads in the case. ((Jordan1200 of the XLFORUM http://xlforum.net/forums/showthread.php?t=2068069&page=9)) | + | * **Torque value**: 10-15 ft. Lbs. (14-21 Nm) on a dry plug with good threads in the case. ((Jordan1200 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-bottom-end/193013-tap-extention/page9?t=2068069&page=9)) |
| * You should use anti-seize on the plug threads before installing it to help prevent galling and damage upon the next removal. The anti-seize will add pre-load to the threads so you should also lower the torque applied when installing the it to avoid a new problem with a broken or stretched bolt. ((Hippysmack)) | * You should use anti-seize on the plug threads before installing it to help prevent galling and damage upon the next removal. The anti-seize will add pre-load to the threads so you should also lower the torque applied when installing the it to avoid a new problem with a broken or stretched bolt. ((Hippysmack)) | ||
| - | * 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 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 https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/185860-inspection-plug-leak-tick?t=1988386&highlight=timing+hole+plug)) ((IronMick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/25163-fixing-a-stripped-primary-drain-hole?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. | * 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. | ||
| * 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. | * 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. | ||
| - | * If you can't spin the plug in or out by hand, don't put a lot of torque on it. It may not hold on the next seating. You my want to GENTLY retighten it or try chasing the threads first. ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1541235&highlight=colony+plug&page=4)) | + | * If you can't spin the plug in or out by hand, don't put a lot of torque on it. It may not hold on the next seating. You my want to GENTLY retighten it or try chasing the threads first. ((Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/142250-more-ironhead-hate-hate-hate/page4?t=1541235&highlight=colony+plug&page=4)) |
| - | * The first time you loosen one of these plugs it may be real tight. Don't make the mistake of over-tightening when you install it. You'll probably find that they get tighter all by themselves. ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1541235&highlight=colony+plug&page=4)) | + | * The first time you loosen one of these plugs it may be real tight. Don't make the mistake of over-tightening when you install it. You'll probably find that they get tighter all by themselves. ((Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/142250-more-ironhead-hate-hate-hate/page4?t=1541235&highlight=colony+plug&page=4)) |
| - | + | ||
| - | + | ||
| - | + | ||
| ====== Permanent Repair Options ====== | ====== Permanent Repair Options ====== | ||
| - | * In theory, the best advice is to split your cases and have it done proper by your local machine shop. ((MTD of the XLFORUM http://xlforum.net/forums/showthread.php?t=39069&highlight=timing+hole+plug)) | + | * In theory, the best advice is to split your cases and have it done proper by your local machine shop. ((MTD of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/23631-timing-hole-plug-repair?t=39069&highlight=timing+hole+plug)) |
| * However, 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. | * However, 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. | ||
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| * Try an [[techtalk:ref:engmech01a#using_an_aftermarket_drain_plug_or_bolt_with_longer_threads|Aftermarket plug or bolt with longer threads]] to catch the good threads in the rear of the case. | * Try an [[techtalk:ref:engmech01a#using_an_aftermarket_drain_plug_or_bolt_with_longer_threads|Aftermarket plug or bolt with longer threads]] to catch the good threads in the rear of the case. | ||
| * Try [[techtalk:ref:engmech01a#cutting_new_threads_for_an_oversized_plug|Cutting new threads for an oversized plug]]. | * Try [[techtalk:ref:engmech01a#cutting_new_threads_for_an_oversized_plug|Cutting new threads for an oversized plug]]. | ||
| + | |||
| ===== Chasing the Existing Threads ===== | ===== Chasing the Existing Threads ===== | ||
| See also the [[techtalk:ref:tools023|warped or damaged thread repair]] section of the Sportsterpedia. | See also the [[techtalk:ref:tools023|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. \\ | + | * 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 https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-bottom-end/193013-tap-extention/page3?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 ==== | ==== Tools Needed ==== | ||
