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techtalk:ih:oil03p [2021/11/11 00:16] hippysmack [77-85 Oil Pump Inspection] |
techtalk:ih:oil03p [2021/11/11 21:26] hippysmack [Inspect both gerotor sets] |
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| * 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. | ||
| - | * Visually inspect the inside of the check valve to make sure the little disc up inside it is fully closed. \\ Loose metal particles can get stuck between the disc and the valve body keeping the disc from closing. \\ If you find metal debris in the check valve, there may also be metal that made it's way past the check into the motor. | ||
| - | |Silicone 'gummy bear' sheet found in the feed side|Oil check valve stuck open with metal debris ((photo by Screwloose of the XLFORUM http://xlforum.net/forums/showthread.php?t=1979566))| | + | |Silicone 'gummy bear' sheet found in the feed side ((photo by (-_-) of the XLFORUM, annotated by Hippysmack http://xlforum.net/forums/showthread.php?t=2074835&page=3))| |
| - | |{{:techtalk:evo:oil:oil_pump_damage_3_by_-_-_-_annotated.jpg?direct&300|}} ((photo by (-_-) of the XLFORUM, annotated by Hippysmack http://xlforum.net/forums/showthread.php?t=2074835&page=3))|{{:techtalk:ih:oil:1977-1985_oil_pump_check_valve_by_screwloose.jpg?direct&300|}}| | + | |{{:techtalk:evo:oil:oil_pump_damage_3_by_-_-_-_annotated.jpg?direct&300|}} | |
| === Inspect the ridge in the cover === | === Inspect the ridge in the cover === | ||
| Line 88: | Line 87: | ||
| * 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/cover needs to be replaced has never been publicized by the MoCo. \\ They apparently didn't want to get into the weeds... as I've done here. | * How many scratches or how deep the scratches need to be before the pump housing/cover needs to be replaced has never been publicized by the MoCo. \\ They apparently didn't want to get into the weeds... as I've done here. | ||
| - | * 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, it can't absorb any of that pressure. \\ So excess pressure is sent backwards from the restrictions. \\ This is how oil can recirculate form the feed outlet back to the feed inlet through out of service clearances and oil pump pad wear. \\ When the pressure is reverted backward, it runs back to the inlet side of the pump. \\ If backpressure is allowed to constantly run back to the inlet side, it will send oil back up the feed hose. \\ If you normally would have say 4psi at idle on the pump outlet, you'd now have 2 psi on the outlet and 2 psi going back to the inlet. | + | * 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, it can't absorb any of that pressure. \\ So excess pressure is sent backwards from the restrictions. \\ This is how oil can recirculate from the feed outlet back to the feed inlet through out of service clearances and oil pump pad wear. \\ When the pressure is reverted backward, it runs back to the inlet side of the pump. \\ If backpressure is allowed to constantly run back to the inlet side, it will send oil back up the feed hose. \\ If you normally would have say 4psi at idle on the pump outlet, you'd now have 2 psi on the outlet and 2 psi going back to the inlet. |
| * Consequently, more oil will recirculate thru the feed side than the return side if both big pads have identical width and depth elongated scratches. \\ The backpressure from the feed side would push more oil faster under the gerotors than the return side with less backpressure. \\ If the oil tank vent line is stopped up, backpressure on the return side of the pump will be greater and send more oil under the gerotors back to the sump. | * Consequently, more oil will recirculate thru the feed side than the return side if both big pads have identical width and depth elongated scratches. \\ The backpressure from the feed side would push more oil faster under the gerotors than the return side with less backpressure. \\ If the oil tank vent line is stopped up, backpressure on the return side of the pump will be greater and send more oil under the gerotors back to the sump. | ||
| * 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. | ||
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| * The gerotors are much taller than the pin thickness. | * The gerotors are much taller than the pin thickness. | ||
| * So the height of the slot allows a fudge factor on quick throttle blips and the gerotors won't be affected. \\ The gearshaft will rise some on higher throttle and there is built in "up and down" clearance in the pump to allow this. \\ | * So the height of the slot allows a fudge factor on quick throttle blips and the gerotors won't be affected. \\ The gearshaft will rise some on higher throttle and there is built in "up and down" clearance in the pump to allow this. \\ | ||
| - | * The pins are not pressed into the gearshaft and the holes in the gearshaft for the pins are different depths on several used gearshafts inspected. \\ Knowing this, it makes sense to be aware that the holes in the shaft can wallow out or the loose fit of the pins can wear the pins faster. \\ You can buy a handful of new pins only to find they are all different dims as well. \\ If you find real slop in the pin fit to the pins, either replace the pins and/or the gearshaft. \\ Do not buy hardened pins as that will defeat the purpose of the "shear pin" design. If the pins only protrude slightly into the gerotor slots, use longer pins. \\ | + | * The pins are not pressed into the gearshaft and the holes in the gearshaft for the pins are different depths on several used gearshafts inspected. \\ Knowing this, it makes sense to be aware that the holes in the shaft can wallow out or the loose fit of the pins can wear the pins faster. \\ You can buy a handful of new pins only to find they are all different dims as well. \\ If you find real slop in the pin fit to the gearshaft, either replace the pins and/or the gearshaft. \\ Do not buy hardened pins as that will defeat the purpose of the "shear pin" design. If the pins only protrude slightly into the gerotor slots, use longer pins. \\ |
| The pics below are used parts but show the pin locations and how they look installed with a gerotor on the shaft. \\ | The pics below are used parts but show the pin locations and how they look installed with a gerotor on the shaft. \\ | ||
| Line 154: | Line 153: | ||
| {{:techtalk:ih:oil:1977-1985_oil_pump_gearshaft_pins_by_hippysmack.jpg?direct&300|}} {{:techtalk:ih:oil:77-85_oil_pump_gearshaft_pin_location_3_by_hippysmack.jpg?direct&300|}} {{:techtalk:ih:oil:77-85_oil_pump_gearshaft_pin_location_5_by_hippysmack.jpg?direct&300|}} \\ | {{:techtalk:ih:oil:1977-1985_oil_pump_gearshaft_pins_by_hippysmack.jpg?direct&300|}} {{:techtalk:ih:oil:77-85_oil_pump_gearshaft_pin_location_3_by_hippysmack.jpg?direct&300|}} {{:techtalk:ih:oil:77-85_oil_pump_gearshaft_pin_location_5_by_hippysmack.jpg?direct&300|}} \\ | ||
| - | |||
| ===== Inspect both gerotor sets ===== | ===== Inspect both gerotor sets ===== | ||
| - | Clean both gerotor sets with solvent, brake cleaner et., and inspect them closely for cracks. \\ | + | |
| + | Clean both gerotor sets with solvent, brake cleaner etc. \\ | ||
| + | \\ | ||
| + | **Inspect inner and outer pieces of both gerotor sets closely for cracks (most cracks are going to run vertically)**. \\ | ||
| It may be hard to see cracks from a distance or when the gerotors are oily / dirty. \\ | It may be hard to see cracks from a distance or when the gerotors are oily / dirty. \\ | ||
| - | The outer return piece below was cracked but not all the way through. Being cracked at all is still a problem (could result in lower oil pressure). \\ | + | Cracks can happen when debris gets pinned between the inner and outer gerotors. \\ |
| - | Replace any gerotors with damaged teeth, nicks or cracks. The problem will only get worse. \\ | + | As they spin around and pinch something between them, the offending item tries to bind or lock up the gerotors while the geasrshaft still wants to spin. \\ |
| - | {{:techtalk:ih:oil:1983l-1985_outer_gerotor-_cracked_by_attaxic.jpg?direct&300|}} ((photo by Attaxic of the XLFORUM http://xlforum.net/forums/showthread.php?t=2078758&page=4)) \\ | + | Technically, the solid shear pins on the gearshaft should also be checked for damage if you find a cracked gerotor. \\ |
| + | The pins should shear before that much pressure is put on the gerotors. \\ | ||
| + | If aftermarket hardened pins are used instead of OEM pins, they could hold up and not shear which transfers gearshaft energy to the gerotors instead. \\ | ||
| + | This is another example of parts designed to fail before others down line do. \\ | ||
| + | |||
| + | (L - below) The outer return piece below was cracked but not all the way through. Being cracked at all is still a problem (could result in lower oil pressure). \\ | ||
| + | Replace any gerotors with damaged teeth, nicks or cracks. \\ | ||
| + | The problem will only get worse (gerotor will break into pieces) and oil pressure will be lower until the gerotor breaks. \\ | ||
| + | (R - below) The inner feed gerotor broke into 4 separate pieces starting from the slot in the gerotor where the gearshaft pin catches it. \\ | ||
| + | |||
| + | {{:techtalk:ih:oil:1983l-1985_outer_gerotor-_cracked_by_attaxic.jpg?direct&300|}} ((photo by Attaxic of the XLFORUM http://xlforum.net/forums/showthread.php?t=2078758&page=4)) {{:techtalk:ih:oil:1977-1985_inner_feed_gerotor_broken_by_freewheeler.jpg?direct&300|}} ((photo by Freewheeler of the XLFORUM http://xlforum.net/forums/showthread.php?threadid=1869407)) \\ | ||
| \\ | \\ | ||
| **Check inner to outer gerotor clearance on each gerotor set**. \\ | **Check inner to outer gerotor clearance on each gerotor set**. \\ | ||
| Each gerotor set is made with an inner and outer piece. Mesh the two pieces together (as they normally would sit in operation). \\ | Each gerotor set is made with an inner and outer piece. Mesh the two pieces together (as they normally would sit in operation). \\ | ||
| + | This clearance has a direct relationship to oil pump flow and oil pressure. \\ | ||
| + | The wider the clearance the more the gerotors lose their ability to hold enough pressure to the outlet cavity. \\ | ||
| + | They also the ability to transfer oil from the feed cavity back to the inlet cavity and recirculate oil within the oil pump. \\ | ||
| + | |||
| * Arrange so there is 1 inner tooth facing the center of the wide outer radius. \\ Use a feeler gauge between the inner tooth and outer radius there for a maximum of .004" clearance between them. \\ If the clearance is larger than .004", replace the affected gearotor set. Repeat for the other gerotor set. | * Arrange so there is 1 inner tooth facing the center of the wide outer radius. \\ Use a feeler gauge between the inner tooth and outer radius there for a maximum of .004" clearance between them. \\ If the clearance is larger than .004", replace the affected gearotor set. Repeat for the other gerotor set. | ||
| {{:techtalk:ih:oil:1977-1985_oil_pump_gerotors_-_checking_clearance_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\ | {{:techtalk:ih:oil:1977-1985_oil_pump_gerotors_-_checking_clearance_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\ | ||
| + | |||
| \\ | \\ | ||
| - | * Measure the height of each inner and outer gerotor set. \\ Each inner and outer piece (feed side) should be the same height, each inner and outer (return side) should be the same height. \\ Replace gerotors as a set respectively if the inner and outer pieces are not the same height. \\ A micrometer will reveal tighter measurements rather than the caliper used below. \\ However, there are so many small variances in these pumps that less than .001" increments isn't going to be the hill to trash your pump on. \\ | + | * **Measure the height of each inner and outer gerotor set**. \\ Each inner and outer piece (feed side) should be the same height, each inner and outer (return side) should be the same height. \\ Replace gerotors as a set respectively if the inner and outer pieces are not the same height. \\ A micrometer will reveal tighter measurements rather than the caliper used below. \\ However, there are so many small variances in these pumps that less than .001" increments isn't going to be the hill to trash your pump on. \\ |
| {{:techtalk:ih:oil:77-85_gerotor-_measuring_feed_set_height_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) {{:techtalk:ih:oil:77-85_gerotor-_measuring_return_set_height_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\ | {{:techtalk:ih:oil:77-85_gerotor-_measuring_feed_set_height_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) {{:techtalk:ih:oil:77-85_gerotor-_measuring_return_set_height_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\ | ||
| + | |||
| ===== Inspect the Seals and O-rings ===== | ===== Inspect the Seals and O-rings ===== | ||
| + | |||
| It's never a bad idea to replace seals and O-rings every time you go into the oil pump. \\ | It's never a bad idea to replace seals and O-rings every time you go into the oil pump. \\ | ||
| If they still hold tight enough and aren't damaged or compromised, they can be reused. \\ | If they still hold tight enough and aren't damaged or compromised, they can be reused. \\ | ||
| Line 186: | Line 204: | ||
| {{:techtalk:ih:oil:1977-1985_oil_check_valve_assembly_pic_1_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) {{:techtalk:ih:oil:12036_and_12036a_outer_plate_seals.jpg?direct&300|}} ((photo by Hippysmack)) \\ | {{:techtalk:ih:oil:1977-1985_oil_check_valve_assembly_pic_1_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) {{:techtalk:ih:oil:12036_and_12036a_outer_plate_seals.jpg?direct&300|}} ((photo by Hippysmack)) \\ | ||
| + | |||
| ===== Inspect the oil check valve ===== | ===== Inspect the oil check valve ===== | ||
| + | |||
| [[techtalk:ih:oil01#oil_pump_check_valve|Click Here]] to read more about the oil pump check valve in the Sportsterpedia. \\ | [[techtalk:ih:oil01#oil_pump_check_valve|Click Here]] to read more about the oil pump check valve in the Sportsterpedia. \\ | ||
| * Make sure it's not clogged and the internal spring closes the cup / disc properly. \\ The spring loaded cup inside the valve should be free to move and should return to it's closed, seated position. \\ It the check valve is damaged in any way, the complete valve assembly should be replaced. \\ There are no replaceable parts to it. | * Make sure it's not clogged and the internal spring closes the cup / disc properly. \\ The spring loaded cup inside the valve should be free to move and should return to it's closed, seated position. \\ It the check valve is damaged in any way, the complete valve assembly should be replaced. \\ There are no replaceable parts to it. | ||
| + | * Loose metal particles can get stuck between the disc and the valve body keeping the disc from closing. \\ If you find metal debris in the check valve, there may also be metal that made it's way past the check into the motor. | ||
| + | |||
| + | (R) below, the check valve was stuck open with metal debris. \\ | ||
| + | |||
| + | {{:techtalk:ih:oil:77-85_oil_check_valve_1_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) {{:techtalk:ih:oil:77-85_oil_check_valve_drawing_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) {{:techtalk:ih:oil:1977-1985_oil_pump_check_valve_by_screwloose.jpg?direct&300|}} ((photo by Screwloose of the XLFORUM http://xlforum.net/forums/showthread.php?t=1979566)) \\ | ||
| - | {{:techtalk:ih:oil:77-85_oil_check_valve_1_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) {{:techtalk:ih:oil:77-85_oil_check_valve_drawing_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\ | ||
| ===== Inspect the spring washer ===== | ===== Inspect the spring washer ===== | ||
