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--- techtalk:ref:svcproc11l [2023/10/23 20:09]
hippysmack [Tips to Avoid Hurting Your Dogs]
+++ techtalk:ref:svcproc11l [2024/04/10 02:34] (current)
hippysmack [Not Using the Clutch to Shift]
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 {{ :common:sporsterpedia_by_graywolf_of_the_xlforum.gif?nolink& |Logo by Graywolf of the XLFORUM}}
 ====== Gear Dog Damage: Inspection and Causes ======
 This article is written in defense of the dogs on the gears. \\
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 Notice that the 1st to 4th GEAR drawings show 5 gears are involved in transmitting power from the clutch to the Drive Sprocket. \\
 In each of these GEARS, power is transmitted thru the countershaft using C5 to drive M5 (and thus the Drive Sprocket). \\
-Various sliding gear DOGS must to be engaged to one of their adjacent SLEEVED gears to have power flow, even though the 'teeth' on the sliding gear may not be involved in that power flow path. \\
+Various sliding gear DOGS must to be engaged to one of their adjacent SLEEVED gears to have power flow on the countershaft. \\
+(even though the 'teeth' on the sliding gear may not be involved in that power flow path) \\
 Once the SPLINED gear with DOGS engages to a neighboring SLEEVED gear, that SLEEVED gear is now locked to and turns with the shaft. \\
-When the transmission 5th GEAR is selected, the Mainshaft SPLINED M2 gear is moved so it's DOGS engage the M5 SLEEVED gear, thereby flowing power from the clutch to the Drive Sprocket in a 1:1 ratio. \\
+When the transmission 5th GEAR is selected; \\
+The Mainshaft SPLINED M2 gear is moved so it's DOGS engage the M5 SLEEVED gear, thereby flowing power from the clutch to the Drive Sprocket in a 1:1 ratio. \\
-A chart for neutral is included below since, technically, power flows from the 2 SPLINED gears to the 2 SLEEVED gears when the clutch is engaged, although power ends there. The Countershaft SLEEVED gears in that situation 'idling', with no way of locking themselves to the countershaft to flow power elsewhere. \\
+A chart for neutral is included below since, technically, power flows from the 2 SPLINED gears to the 2 SLEEVED gears when the clutch is engaged, although power ends there. \\
+The Countershaft SLEEVED gears in that situation are 'idling', with no way of locking themselves to the countershaft to flow power elsewhere. \\
 Click on any chart to enlarge: ((Drawings by Hippysmack with help from IXL2Relax with graphic design)) \\
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 The outside edge of the dogs also have a back cut (or chamfer) to help guard against chipping when sliding in or out of mesh against it's mating gear. \\
-The gears below, as you can see, have no internal splines and are sleeved on the shaft over bearings. \\
+The used gears below, as you can see, have no internal splines and are sleeved on the shaft over bearings. \\
 {{:techtalk:ref:svcproc:trans_gears_-_dogs_and_slots_by_hippysmack.jpg?direct&400|}} ((photo by Hippysmack of the XLFORUM)) \\
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 ===== Worn Dogs (hopping out of gear) =====
 The gear dogs can wear just about anywhere around them for several different reasons. \\
-The most common thing that happens is when the corners get rounded off instead of being flat on the edges. ((mikeLI_77 of the XLFORUM http://xlforum.net/forums/showthread.php?t=2072870)) \\
+The most common thing that happens is when the corners get rounded off instead of being flat on the edges. ((mikeLI_77 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-drivetrain/sportster-motorcycle-transmission-clutch-primary-secondary-drive/196356-popped-outa-2nd-gear?t=2072870)) \\
 A gear may hop out of dog mesh.  \\
 It feels like the transmission jumped into neutral for a second and then jumped back in gear. \\
-It's usually a momentary hop-out. In other words, it hops out and then right back in. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=2082693&page=4)) \\
+It's usually a momentary hop-out. In other words, it hops out and then right back in. ((aswracing of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-drivetrain/sportster-motorcycle-transmission-clutch-primary-secondary-drive/205269-possible-slipping-in-drivetrain-looking-for-help/page4?t=2082693&page=4)) \\
 So the bike hesitates during acceleration and then jerks back forward again. \\
-This is the common cause of hop-out, although checking the pawl adjustment with a .116" drill bit per the service manual should certainly be done first. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=2072870)) \\
+This is the common cause of hop-out, although checking the pawl adjustment with a .116" drill bit per the service manual should certainly be done first. ((aswracing of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-drivetrain/sportster-motorcycle-transmission-clutch-primary-secondary-drive/196356-popped-outa-2nd-gear?t=2072870)) \\
 But you can check that on your way to pulling the transmission. \\
-|  Worn dogs ((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=2072870))  ||
+|  Worn dogs ((photo by aswracing of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-drivetrain/sportster-motorcycle-transmission-clutch-primary-secondary-drive/196356-popped-outa-2nd-gear?t=2072870))  ||
 |{{:techtalk:ref:svcproc:worn_dogs_1_by_aswracing.jpg?direct&300|}}|{{:techtalk:ref:svcproc:worn_dogs_2_by_aswracing.jpg?direct&300|}}|
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 So the gear hops (or backs) out of dog mesh. \\
 Meanwhile, the fork is still trying to hold the gear in mesh and forces the gear back "home" and the cycle continues. \\
 ===== Dog Repair =====
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 Below are a few common things that can cause or contribute to gear dog wear/damage while shifting. \\
+==== Neutral to 1st on a Cold Start ====
+Firing up in neutral on a cold start is sort of like firing up in 1st gear with the clutch released. \\
+The transmission doesn't disengage from the motor due to stuck clutch plates. \\
+On initial startup, the clutch plates are usually stuck together from thick, cold (ambient) oil temps. \\
+Even with the clutch lever pulled, the engine stays engaged to the transmission since the clutch plates can't pull apart and release pressure on the mainshaft. \\
+So the bike lunges forward with engine RPM still trying to turn the transmission while the transmission is in neutral. \\
+The bike lunges forward slightly until that movement separates the clutch plates. \\
+Afterwards, the clutch lever is then in control of the plates again. This is generally not an issue after the bike has been run for a spell, shut down and restarted. \\
+Or at least until the oil cools to ambient temp again and thickens enough to stick the clutch plates together again. \\
+The mechanics of the situation when shifting from neutral to 1st on a cold start; \\
+The rear tire is not moving so the countershaft is locked dead still and the mainshaft is turning at idle speed. \\
+Pushing the shift pedal towards 1st gear forces countershaft 3rd gear to slide to mate with countershaft 1st gear. \\
+When these 2 gears combine by locking dogs to slots, both the mainshaft and countershaft are now being powered by the motor. \\
+C3 gear is splined to the countershaft and it locks C1 gear to the countershaft. M1 gear is splined to the mainshaft. \\
+C1 and M1 gear teeth are in constant mesh so both shafts are being powered by the motor at this point poised to turn at idle speed. \\
+But, the rear tire is still not moving (default from the weight of the bike and the rider). \\
+How this affects the dogs; \\
+IF the positioning of the dogs and slots is so that they combine together without hitting corners, you'll just get the slight lunge forward. \\
+These gears are tough and the jolt is not as bad on the dog/slot relationship if there is enough contact between them during the jolt. \\
+IF the positioning of the dogs and slots allows them to hit corners before going into each others "dog land", then the corners on both gears take the brunt. \\
+This can be a rough transition for the dogs and can contribute to wearing on the corners and hopping out of gear. \\
+It's akin to hitting a metal baseball bat on a tree trunk. \\
+The tree (rear tire) just takes on vibration, the bark (slot corner) can get indented and the bat (dog corner) can get indented. \\
+It's a rough transition that can damage the dog corners and cause them to hop out later. \\
+If firing up in 1st instead, you'll still get the lunge forward (even holding the clutch lever in) but the dogs are already meshed with their corresponding slots. \\
+This minimizes the possibility of damage to the dogs and slots. \\
 ==== Delayed Shifting ====
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 Closing the throttle before pulling the clutch lever will keep from preloading the mainshaft while the clutch is disengaged and will allow for disengagement of dogs without that load on them. \\
 It's important for that load not to be on the gears. \\
-With added load, as the gear combinations separate from one gear to go to the next, the sliding gear is pressed harder against the adjacent gear it is trying to pull away from. That could lead to burring or chipping of the corners with load applied then as they separate. \\ The dog corners are chamfered to discourage chipping in that instance but that is not a fool proof solution. \\
+With added load, as the gear combinations separate from one gear to go to the next, the sliding gear is pressed harder against the adjacent gear it is trying to pull away from. That could lead to burring or chipping of the corners with load applied then as they separate. \\
+The dog corners are chamfered to discourage chipping in that instance but that is not a fool proof solution. \\
 ==== Not Using the Clutch to Shift ====
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 The dogs do not all turn at the same speed. \\
 So a sliding gear will most likely be turning at a different speed than the gear it either has to separate from or come together with. \\
-If both these gears are being driven, neither has the ability to slow down to allow ease of dog mesh. \\
+If both these gears are being driven, neither has the ability to slow down or otherwise concede to allow ease of dog mesh. \\
 That will eventually lead to crunching dog corners no matter how experienced one is at speed shifting. \\
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 This can also lead to damaging the gear dogs as they try to mate with both the engine and rear tire loading the transmission. \\
 [[techtalk:evo:priclutch01#clutch_release_adjustment_-_why_how|Click Here]] to see the Evo clutch page in the Sportsterpedia. \\
 ===== Shifter Out of Adjustment =====
 The shifter assembly has designed "slop" or looseness, built in by the factory, to buffer the various conditions involved with the shifter and the transmission. \\
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 If you are sure the adjustment is correct, you may need to dig deeper looking for other parts in need of repair. \\
 [[techtalk:ref:svcproc11a|Click Here]] to see the page Setting 1991-2003 Shift Pawl Position in the Sportsterpedia. \\
 ===== Worn Parts =====
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     * Fire up in 1st gear with the clutch pulled. \\
   * **Shifting Habits**.
-    *  It's best to shift soon after pulling the clutch \\ (Sportster) dog type transmissions don't have synchronizers to match gear speeds before engagement. So when you shift, the dogs just slam into the gear next to them. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1291098)) \\ The closer you can speed match the gears, the less violent that engagement will be. \\ Timing your upshifts so that while the clutch is in and the throttle chopped, the engine falls to about the right rpm for the next gear, will help. \\ Likewise a little blip of the throttle while the clutch is in on the downshift, to bring the motor up to right rpm for the lower gear, will help. \\
+    *  It's best to shift soon after pulling the clutch \\ (Sportster) dog type transmissions don't have synchronizers to match gear speeds before engagement. So when you shift, the dogs just slam into the gear next to them. ((aswracing of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-drivetrain/sportster-motorcycle-transmission-clutch-primary-secondary-drive/126748-gear-dogs?t=1291098)) \\ The closer you can speed match the gears, the less violent that engagement will be. \\ Timing your upshifts so that while the clutch is in and the throttle chopped, the engine falls to about the right rpm for the next gear, will help. \\ Likewise a little blip of the throttle while the clutch is in on the downshift, to bring the motor up to right rpm for the lower gear, will help. \\
     * It's best to shift with a little attitude instead of a lazy shift (easing the shift pedal with your foot). \\
     * It's best to close the throttle before pulling the clutch during a shift. \\ The 1998 service manual on shifting gears reads: \\ //__close the throttle, disengage the clutch and lift the gear shifter pedal up to the end of its travel. Engage the clutch and operate the throttle gradually__.//