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| techtalk:ih:oil03p [2024/05/07 23:32] – [Inspect the oil pump cover and body] hippysmack | techtalk:ih:oil03p [2025/02/26 20:36] (current) – hippysmack | ||
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| ===== Inspect the oil pump cover and body ===== | ===== Inspect the oil pump cover and body ===== | ||
| - | === Look for debris while disassembling === | + | ==== Look for debris while disassembling ==== |
| - | Grit / Debris found in the oil pump can give clues to potential motor problems. \\ | + | |
| - | While removing each part starting from the cover, make note of the color of the oil, any grit or metal particles and what color they are. \\ | + | Grit / Debris found in the oil pump can give clues to potential motor problems.\\ |
| + | While removing each part starting from the cover, make note of the color of the oil, any grit or metal particles and what color they are. | ||
| * What color debris or glitter came from where? | * What color debris or glitter came from where? | ||
| - | | + | |
| - | * Silver (aluminum) colored particles/ | + | * Silver (aluminum) colored particles/ |
| - | * Silver (metal) colored particles/ | + | * Silver (metal) colored particles/ |
| * Note the size and texture of particles/ | * Note the size and texture of particles/ | ||
| * Which side of the pump is it in, feed or return?: \\ Debris in the return side came out of the motor into the pump. \\ Debris in the feed side came from the oil tank (which most likely came from the motor to the oil tank). \\ For long term diagnosis, this may not find a smoking gun problem. \\ But in cases of sudden failure, it may be an important clue as in where to start looking for problems. | * Which side of the pump is it in, feed or return?: \\ Debris in the return side came out of the motor into the pump. \\ Debris in the feed side came from the oil tank (which most likely came from the motor to the oil tank). \\ For long term diagnosis, this may not find a smoking gun problem. \\ But in cases of sudden failure, it may be an important clue as in where to start looking for problems. | ||
| * Silicone should not be used anywhere on a Sportster motor. \\ If so, you may find pieces of it in the oil pump or in the small orifics and oil galleys within the motor. \\ The push / pull of crankcase pressure can implode gaskets and especially sealants like silicone. \\ This will stop up the oil paths in the motor and if caught early enough, can be flushed out before catastrophic damage happens. | * Silicone should not be used anywhere on a Sportster motor. \\ If so, you may find pieces of it in the oil pump or in the small orifics and oil galleys within the motor. \\ The push / pull of crankcase pressure can implode gaskets and especially sealants like silicone. \\ This will stop up the oil paths in the motor and if caught early enough, can be flushed out before catastrophic damage happens. | ||
| - | |Silicone 'gummy bear' sheet found in the feed side ((photo by (-_-) of the XLFORUM, annotated by Hippysmack https:// | + | |Silicone 'gummy bear' sheet found in the feed side ((photo by (-_-) of the XLFORUM, annotated by Hippysmack https:// |
| - | |{{: | + | |{{: |
| - | === Inspect the ridge in the cover === | + | ==== Inspect the ridge in the cover ==== |
| - | * Using a straightedge across the feed gerotor set (installed) surface; \\ Measurement should be taken with a feeler gauge from the gerotor surface to the ridge of the edge of the aluminum cover. \\ The thin, feed gerotors (26492-75) in the oil pump cover (26486-75) should extend .001" | + | |
| - | {{: | + | * Using a straightedge across the feed gerotor set (installed) surface; \\ Measurement should be taken with a feeler gauge from the gerotor surface to the ridge of the edge of the aluminum cover. \\ The thin, feed gerotors (26492-75) in the oil pump cover (26486-75) should extend .001"-.005" above the cover' |
| - | === Inspect the gerotor surface for flatness in the oil pump cover and housing === | + | {{: |
| - | An oil pump cover found with an uneven gerotor surface should be removed. \\ | + | |
| - | If the gerotor widths measure equally but they are not equal in height when placed into the cover, the cover surface is not flat. \\ | + | |
| - | If the gerotors will not sit flat in the cover then the cover should be replaced. \\ | + | |
| - | Be sure to check the gerotors in the new/ | + | |
| - | Be sure to check the gerotor surface in the housing also. | + | |
| - | === Inspect the gerotor surface in the cover and housing | + | ==== Inspect the gerotor surface |
| - | Many (most perhaps) used oil pumps have scratches on both the gerotors and pump surfaces that the gerotors ride on. \\ | + | |
| - | But, there is one certain spot that seems to be scratched more times than others. ((Hippysmack of the XLFORUM https:// | + | |
| - | It's on the larger of the two pads in the pump body and the cover seem to usually have more wear. \\ | + | |
| - | Sometimes, the small pad is scratched or damaged also but not always. \\ | + | |
| - | The gap between the inner and outer gerotors on both the feed and return sides tends to be scratched as in the pics below. \\ | + | |
| - | Debris caught between these two gears cannot slide over and fall to the other cavity and out of the pump. \\ | + | |
| - | It gets locked between the teeth and ripped across the aluminum surface. \\ | + | |
| - | In theory, no particles of any size should be able to spin around to the small pad. \\ | + | An oil pump cover found with an uneven gerotor surface |
| - | This is mainly due to the pressure generated by the spring washer and the gerotor spacing there. \\ | + | |
| - | Also, any debris picked up from the source side cavity should drop down into the feed side cavity and out of the pump. \\ | + | |
| - | The side toward | + | |
| - | The inner and outer gerotors come together on the other side (right side). \\ | + | |
| - | This spacing relationship doesn' | + | |
| - | But in reality, debris gets caught in or between | + | ==== Inspect the gerotor surface |
| - | Some then find their way under the gerotors while the spring washer flexes from the stress. \\ | + | |
| - | The debris spins around under the gerotors and wears scratches | + | |
| - | There should be some amount of reduced pressure because of the scratches (depending on how may and how deep). \\ | + | Many (most perhaps) used oil pumps have scratches on both the gerotors and pump surfaces that the gerotors ride on. \\ But, there is one certain spot that seems to be scratched more times than others. ((Hippysmack of the XLFORUM https:// |
| - | Pressure generated to the output cavity can squirt back to the input side through these scratches. \\ | + | |
| - | How much pressure loss would depend on the width, depth, length of the scratches and oil viscosity at the time. \\ | + | |
| - | To make the pump inoperative or not make pressure (from the scratches alone); \\ | + | |
| - | The scratches would have to be proportional to the relative volume of all four gerotor reservoirs combined. \\ | + | |
| - | Then, the check valve would have to accept less pressure flow than the backpressure from the pump. \\ | + | |
| - | The gerotor surface in the cover would have to be eat up pretty bad to make the pump completely ineffective. \\ | + | |
| - | The pump would have less pressure loss with multi-weight or straight weight oil when cold than hot. \\ | + | |
| - | They' | + | |
| - | | Gerotor rotation (cover shown) ((photos by Hippysmack https:// | + | |{{: |
| - | |{{: | + | |
| - | {{: | + | {{: |
| - | === Classifying Scratches in Gerotor Surfaces | + | ==== Classifying Scratches in Gerotor Surfaces ==== |
| - | HD says that if there are any notable scratches on the gerotor riding surfaces in the oil pump housing or cover, then they should be replaced. \\ | + | |
| - | Hagen–Poiseuille Equation to calculate flow pressure drop: ((Hippysmack https:// | + | HD says that if there are any notable scratches on the gerotor riding surfaces in the oil pump housing or cover, then they should be replaced. \\ Hagen–Poiseuille Equation to calculate flow pressure drop: ((Hippysmack https:// |
| - | Without getting into the weeds on figures (that change with every individual pump), Hagen/ | + | |
| - | That is, doubling the diameter of an outlet increases the flow rate by 16 fold (r4). The larger the outlet, the greater the flow. But in the instance of pump internal leakage, there are two outlets, upstream back to the inlet and downstream into the engine. \\ | + | |
| - | Result: In order for the pump to not produce any flow to the outlet side (downstream), | + | |
| - | + | Further comments by Hippysmack. In thinking about it; | |
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| - | Further comments by Hippysmack: \\ | + | |
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| - | < | + | |
| * Inlet side of the pump feed cavity is first fed by gravity from the oil tank and then by suction assist (vacuum pressure) created by the spinning feed gerotors. | * Inlet side of the pump feed cavity is first fed by gravity from the oil tank and then by suction assist (vacuum pressure) created by the spinning feed gerotors. | ||
| * Inlet side of the pump return cavity is fed solely on suction from the spinning return gerotors. \\ Oil is sucked uphill from the crankcase sump thru a small drilled oil galley in the case to the oil pump. | * Inlet side of the pump return cavity is fed solely on suction from the spinning return gerotors. \\ Oil is sucked uphill from the crankcase sump thru a small drilled oil galley in the case to the oil pump. | ||
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| * There is a certain amount of intermittent pressure lost by design on every gerotor tooth rotation. \\ This is more prevalent on the feed side than return due to back pressure further up the feed oil path. \\ When a tooth first enters the rather long inlet cavity, pressure starts building as it rotates around the end of that cavity. \\ Until the feed tooth is fully over the big pad in the cover, some oil squirts back into the inlet cavity from backpressure. \\ Once the tooth is fully on top of the big pad, pressure builds from there as it rotates toward the outlet cavity. \\ Oil is transferred out the pump from there and the pressure in that side of the gerotor is relieved until the next rotation. | * There is a certain amount of intermittent pressure lost by design on every gerotor tooth rotation. \\ This is more prevalent on the feed side than return due to back pressure further up the feed oil path. \\ When a tooth first enters the rather long inlet cavity, pressure starts building as it rotates around the end of that cavity. \\ Until the feed tooth is fully over the big pad in the cover, some oil squirts back into the inlet cavity from backpressure. \\ Once the tooth is fully on top of the big pad, pressure builds from there as it rotates toward the outlet cavity. \\ Oil is transferred out the pump from there and the pressure in that side of the gerotor is relieved until the next rotation. | ||
| * Elongated scratches in these pads allow a constant amount of generated pressure on the outlet side to squirt back to the inlet side of the pump. \\ This will lower the pressure to the extent of how deep the scratches are. \\ Deep scratches allow more oil pressure or oil flow to recirculate from the outlet back to the inlet within the oil pump. \\ This makes for less oil gauge pressure on the feed side as well as less oil flow to the motor. \\ This makes for less oil flow back to the oil tank. | * Elongated scratches in these pads allow a constant amount of generated pressure on the outlet side to squirt back to the inlet side of the pump. \\ This will lower the pressure to the extent of how deep the scratches are. \\ Deep scratches allow more oil pressure or oil flow to recirculate from the outlet back to the inlet within the oil pump. \\ This makes for less oil gauge pressure on the feed side as well as less oil flow to the motor. \\ This makes for less oil flow back to the oil tank. | ||
| - | * How many scratches or how deep the scratches need to be before the pump housing/ | + | * How many scratches or how deep the scratches need to be before the pump housing/ |
| * Backpressure is greater on the feed side than it is the return side. \\ The feed path from the pump has many turns and restrictions that build pressure. \\ Since oil is not compressible, | * Backpressure is greater on the feed side than it is the return side. \\ The feed path from the pump has many turns and restrictions that build pressure. \\ Since oil is not compressible, | ||
| * Consequently, | * Consequently, | ||
| * I'd guesstimate that there are a whole lot of Sportsters on the road with motors having gerotor pumps with various degrees of scratches. \\ The fact that there hasn't been a lot of talk on degrees of scratches in the oil pump says that most probably don't worry too much about them. \\ But then, you end up seeing that one complete teardown due to an oil pump problem and you get to wondering yourself. | * I'd guesstimate that there are a whole lot of Sportsters on the road with motors having gerotor pumps with various degrees of scratches. \\ The fact that there hasn't been a lot of talk on degrees of scratches in the oil pump says that most probably don't worry too much about them. \\ But then, you end up seeing that one complete teardown due to an oil pump problem and you get to wondering yourself. | ||
| - | * There is only one way to answer that question. You have to do some pressure testing. \\ [[techtalk: | + | * There is only one way to answer that question. You have to do some pressure testing. \\ [[:techtalk: |
| - | * Maybe this will give more people cause to think on the subject of how much is too much or how little is just fine. | + | * Maybe this will give more people cause to think on the subject of how much is too much or how little is just fine. |
| - | </ | + | |
| - | Below are a few used oil pumps showing scratches of varying degrees. Further comments are posted on top of the pics. \\ | + | Below are a few used oil pumps showing scratches of varying degrees. Further comments are posted on top of the pics. \\ These are simply observations and it's up to the individual to decide how much wear on the gerotor surfaces in the oil pump are acceptable. \\ Any marked reusable should still be pressure tested and observed if you'll be using them. \\ |Metal chunk lodged in return inlet. \\ The one medium scratch on big pad is some concern. \\ Small amount of recirculation oil internally. \\ Metal debris lessens amount of pickup oil at once. \\ May be reusable with further observation ((photo by sc72 of the XLFORUM https:// |
| - | These are simply observations and it's up to the individual to decide how much wear on the gerotor surfaces in the oil pump are acceptable. \\ | + | |
| - | Any marked reusable should still be pressure tested and observed if you'll be using them. \\ | + | |
| - | |Metal chunk lodged in return inlet. \\ The one medium scratch on big pad is some concern. \\ Small amount of recirculation oil internally. \\ Metal debris lessens amount of pickup oil at once. \\ May be reusable with further observation ((photo by sc72 of the XLFORUM https:// | + | |{{: |
| - | |{{: | + | |
| - | === Check for cracks in the housing and cover === | + | ==== Check for cracks in the housing and cover ==== |
| - | The cover below was cracked at the oil pressure switch end from tightening the pressure switch too tight. \\ | + | |
| - | The crack was welded over and a Dremil tool was used to reshape the cover. \\ | + | |
| - | Due to warpage during welding, the threads need to be chased with a tap to straighten them back out. \\ | + | |
| - | | Repair on oil pump cover ((photos by acb2 of the XLFORUM https://www.xlforum.net/ | + | The cover below was cracked at the oil pressure switch end from tightening the pressure switch too tight. \\ The crack was welded over and a Dremil tool was used to reshape the cover. \\ Due to warpage during welding, the threads need to be chased with a tap to straighten them back out. |
| - | |{{: | + | |
| - | === Inspect the Housing Roll Pin === | + | | Repair on oil pump cover ((photos by acb2 of the XLFORUM https:// |
| - | The roll pin is installed into the " | + | |{{: |
| - | A roll pin is a spring, that's what keeps it in place. It's not solid because it's NOT supposed to shear. | + | |
| - | The scavenge gerotor is not quite as tall as the " | + | ==== Inspect |
| - | Normally, there is a slight gap between the return gerotor set and the inner plate. Inner plate sits against the shelf, not the return gerotors. \\ | + | |
| - | When you button up the pump and the spring washer tightens the turning of the gearshaft, it's tightening against the feed gerotors, not return. \\ | + | |
| - | So the return side should be free to move up and down with RPM and float off the plate. \\ | + | |
| - | The separator (divider) plates have a slot on their OD that installs over the roll pin. \\ | + | The roll pin is installed into the " |
| - | Normally the only force on the roll pin is stationary pressure from the outer plate wanting to turn with the feed gerotor under it. \\ | + | |
| - | However, sudden jolts or back pressure on the pump can strengthen | + | |
| - | The roll pin in the oil pump housing can be damaged (by the parts in the pump getting in a bind) or by a previous hamfisted pump assembly. \\ | + | |
| - | The pin can be punished by the divider plates enough to wallow the hole it' | + | |
| - | This may be due to foreign matter in the feed or return cavities. \\ | + | |
| - | Any foreign objects that enter the pump can increase the pressure against the plates to move. \\ | + | |
| - | Or the pin can be damaged from simply trying to remove it. \\ | + | |
| - | The hole in the center of the divider plates | + | The scavenge gerotor is not quite as tall as the " |
| - | **Check | + | The separator (divider) plates have a slot on their OD that installs over the roll pin. \\ Normally the only force on the roll pin is stationary pressure from the outer plate wanting to turn with the feed gerotor under it. \\ However, sudden jolts or back pressure on the pump can strengthen that stationary pressure against the roll pin. \\ The roll pin in the oil pump housing can be damaged (by the parts in the pump getting in a bind) or by a previous hamfisted pump assembly. \\ The pin can be punished by the divider plates enough |
| - | Give the roll pin a slight tug with needle nose pliers | + | |
| - | If there is any looseness | + | |
| - | There is nothing wrong with the roll pin in this photo. \\ | + | The hole in the center of the divider plates is off center. The roll pin locates the plates to the housing and the off centered drive shaft. |
| - | {{: | + | |
| - | \\ | + | **Check the roll pin**. \\ Give the roll pin a slight tug with needle nose pliers to make sure it is good and pressed in and doesn' |
| - | \\ | + | |
| + | There is nothing wrong with the roll pin in this photo. \\ {{: | ||
| + | |||
| + | If the roll pin comes out, it will cause damage to the oil pump. If it gets lodged between the inner and outer gerotors, it'll most likely crack the outer piece (weaker of the two pieces). If it gets under the gerotors, it'll get dragged across the gerotor surface in the pump housing or cover. This will end up in scratches on the machined surface and lower oil pressure from the pump due to the scratches. With the roll pin out, the outer plate, under pressure, can spin and wallow out the feed bore in the housing around the plate. | ||
| - | If the roll pin comes out, it will cause damage to the oil pump. If it gets lodged between the inner and outer gerotors, it'll most likely crack the outer piece (weaker of the two pieces). If it gets under the gerotors, it'll get dragged across the gerotor surface in the pump housing or cover. This will end up in scratches on the machined surface and lower oil pressure from the pump due to the scratches. With the roll pin out, the outer plate, under pressure, can spin and wallow out the feed bore in the housing around the plate. \\ | ||
| **If needed, below are some possible ways to remove the roll pin**. \\ | **If needed, below are some possible ways to remove the roll pin**. \\ | ||
| - | | + | Note: Vise Grips will most likely slip off the pin and damage it further, but more importantly damage the pump housing. Heat will most likely expand the aluminum around the pin, squeezing it harder around the pin. these are generally bad ideas for removing the pin. |
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| - You could try running a small tap into the roll pin to cut threads for a small screw, then screw the bolt into the center. \\ Once the bolt hits bottom of the hole, it may push the pin up and out or at least loosen the pin. ((Andy Hog of the XLFORUM https:// | - You could try running a small tap into the roll pin to cut threads for a small screw, then screw the bolt into the center. \\ Once the bolt hits bottom of the hole, it may push the pin up and out or at least loosen the pin. ((Andy Hog of the XLFORUM https:// | ||
| - | - You may or may not need to cut the buggered part off, but you could try to fill the pin with oil and insert a close fitting punch into the hole. The hit the punch with a hammer. The hammer blow may move the pin upward. ((sungod of the XLFORUM https:// | + | - You may or may not need to cut the buggered part off, but you could try to fill the pin with oil and insert a close fitting punch into the hole. The hit the punch with a hammer. The hammer blow may move the pin upward. ((sungod of the XLFORUM https:// |
| - | - This is tedious but would work, if done properly and with a steady hand. \\ This method may also be used if the existing hole is broken out or the is wallowed to where a new pin would not tighten up to the existing hole. You could carefully cut the old pin flush with a Dremil tool, leave the old pin where it is and install a new pin elsewhere. Note: if you drill a new pin hole you must cut new slots in the 2 plates that the pin locates. ((needspeed of the XLFORUM https:// | + | - This is tedious but would work, if done properly and with a steady hand. \\ This method may also be used if the existing hole is broken out or the is wallowed to where a new pin would not tighten up to the existing hole. You could carefully cut the old pin flush with a Dremil tool, leave the old pin where it is and install a new pin elsewhere. Note: if you drill a new pin hole you must cut new slots in the 2 plates that the pin locates. ((needspeed of the XLFORUM https:// |
| - | * First, remove the guts inside and install both divider plates over the old pin to locate them properly. Then drill a small hole (smaller than the pin hole) thru the top plate, thru to the bottom plate and stop when it is dimpled by the drill bit. Remove the plates and finish drilling the second plate. Then use a Dremil tool or file to cut a slot from edge of plate to hole (on ea plate) | + | * First, remove the guts inside and install both divider plates over the old pin to locate them properly. Then drill a small hole (smaller than the pin hole) thru the top plate, thru to the bottom plate and stop when it is dimpled by the drill bit. Remove the plates and finish drilling the second plate. Then use a Dremil tool or file to cut a slot from edge of plate to hole (on ea plate) |
| - | * Reinstall both plates and drill thru the new slots in both to make a dimple in the pump housing, remove plates. | + | * Reinstall both plates and drill thru the new slots in both to make a dimple in the pump housing, remove plates. |
| - | * Drill hole in pump housing to depth of new pin (correct bore size for new pin). \\ It's good to have an index drill bit set (especially for smaller bits). Most drill bits will wallow a hole bigger than what it is written on the bit. Start with a slightly smaller bit than (projected installed OD of the pin dia) into the plates and just enough into the housing to make a dot. Then pull it back apart and square up the housing using the same drill bit. Measure it and drill with bigger bit if needed for the pin. If you drill too wide, the pin won't stay. Roll pins are sized by the dia of the hole needed (1/8" roll pin for 1/8" hole) but the pin will measure bigger than that. Just need to make sure the hole doesn' | + | * Drill hole in pump housing to depth of new pin (correct bore size for new pin). \\ It's good to have an index drill bit set (especially for smaller bits). Most drill bits will wallow a hole bigger than what it is written on the bit. Start with a slightly smaller bit than (projected installed OD of the pin dia) into the plates and just enough into the housing to make a dot. Then pull it back apart and square up the housing using the same drill bit. Measure it and drill with bigger bit if needed for the pin. If you drill too wide, the pin won't stay. Roll pins are sized by the dia of the hole needed (1/8" roll pin for 1/8" hole) but the pin will measure bigger than that. Just need to make sure the hole doesn' |
| - | * Use a metal cutting blade on a Dremil cutting tool to cut the old pin flush with the " | + | * Use a metal cutting blade on a Dremil cutting tool to cut the old pin flush with the " |
| - | * Blow out the new hole with compressed air, press the new roll pin into the new hole and you're done. | + | * Blow out the new hole with compressed air, press the new roll pin into the new hole and you're done. |
| - | **Generally bad ideas for removing the pin**. | + | **The roll pin below was damaged by trying to remove it**. \\ It was removed using electrical side cutters by XLF member, billeuze. ((https:// |
| - | * Vise Grips will most likely slip off the pin and damage it further, but more importantly damage | + | |
| - | * Heat will most likely expand | + | |
| - | **The roll pin below was damaged by trying to remove it**. \\ | + | {{: |
| - | It was removed using electrical side cutters by XLF member, billeuze. ((https:// | + | |
| - | Carefully protect the base and sides of the pump body. \\ | + | |
| - | Odd parts were put inside the pump for a nice height for a fulcrum for the side cutters. \\ | + | |
| - | I squeezed and pried it out. It took 4 or five pries to walk it all the way out. ((photos by billeuze)) \\ | + | |
| - | {{: | + | {{: |
| + | \\ | ||
| - | {{: | + | **The roll pin below was damaged and a second roll pin was added to keep from removing the original pin**. \\ |
| + | In order to add the second pin, additional slots have to be cut into both the inner and outer plates since they are both captured by the roll pin. \\ | ||
| + | {{: | ||
| ===== Inspect the gearshaft and bushings for damage or wear ===== | ===== Inspect the gearshaft and bushings for damage or wear ===== | ||
