Busted shifter shaft
#11
Don't think i would believe it either!
Thanks Dan888! Yes, i did double and triple check everything including the collared washer (good memory!)
So here's the story - I am not sure I would believe it if I were reading it in someone else's post:
In the impact that bent the return spring pin/stud (and busted the shifter shaft) in the direction of "upward" shifter movement also BENT THE STUD'S MOUNTING BOSS IN THE SIDE CASE OF THE ENGINE WITHOUT CRACKING THE CASE!!!!!!!
Yes, the mounting boss that part of the main engine case (left side) is tweaked so that when the new (straight) replacement return spring stud is installed it does not stick out perpendicular to the case, but slightly upward in the one 'o clock direction, the direction the shift lever bent the original stud on impact. This prevents the shift mechanism from traveling far enough in the downshift direction.
I could not believe this could happen without cracking the case or breaking the mounting boss out of the case. I tried to photograph it but could not effectively capture what my eye could see. The boss is machined flat but raised slightly above the surface of the rest of the cast part. The casting (case) is shiny as light reflects off the oil-coated surface, and I can see the flat cast area to the one o' clock position of the mounting boss is slightly depressed/warped. Believe it or not - wow!
As I am already registered for the Sound Rider Rally in Hood River, OR, starting on 8/26, I torqued the stud into the boss to "clock it", then removed it from the case and machined clearance reliefs in the stud to allow the shift mechanism to move its intended amount of travel in the "downshift" direction. I also had to do some minor grinding and clearancing on a few other areas of the shift mechanism to allow proper travel both directions AND proper return to the centered position when the shift lever is released.
All back together, it shifts like new! I can now only wonder if that stud is significantly weakened by the machining I did to it allow proper travel of the shift mechanism???
I am still shocked that an AL engine case could bend or tweak like this without breaking or cracking the case. True story, can't make up the truth!
Sorry for the long explanation but figure it would intrigue the backyard metalurgists!
Thankful to be rolling again!
TC
So here's the story - I am not sure I would believe it if I were reading it in someone else's post:
In the impact that bent the return spring pin/stud (and busted the shifter shaft) in the direction of "upward" shifter movement also BENT THE STUD'S MOUNTING BOSS IN THE SIDE CASE OF THE ENGINE WITHOUT CRACKING THE CASE!!!!!!!
Yes, the mounting boss that part of the main engine case (left side) is tweaked so that when the new (straight) replacement return spring stud is installed it does not stick out perpendicular to the case, but slightly upward in the one 'o clock direction, the direction the shift lever bent the original stud on impact. This prevents the shift mechanism from traveling far enough in the downshift direction.
I could not believe this could happen without cracking the case or breaking the mounting boss out of the case. I tried to photograph it but could not effectively capture what my eye could see. The boss is machined flat but raised slightly above the surface of the rest of the cast part. The casting (case) is shiny as light reflects off the oil-coated surface, and I can see the flat cast area to the one o' clock position of the mounting boss is slightly depressed/warped. Believe it or not - wow!
As I am already registered for the Sound Rider Rally in Hood River, OR, starting on 8/26, I torqued the stud into the boss to "clock it", then removed it from the case and machined clearance reliefs in the stud to allow the shift mechanism to move its intended amount of travel in the "downshift" direction. I also had to do some minor grinding and clearancing on a few other areas of the shift mechanism to allow proper travel both directions AND proper return to the centered position when the shift lever is released.
All back together, it shifts like new! I can now only wonder if that stud is significantly weakened by the machining I did to it allow proper travel of the shift mechanism???
I am still shocked that an AL engine case could bend or tweak like this without breaking or cracking the case. True story, can't make up the truth!
Sorry for the long explanation but figure it would intrigue the backyard metalurgists!
Thankful to be rolling again!
TC
#12
Glad you got it going so as not to ruin your upcoming ride. Yeah, it's not that unusual for aluminum to give some like that. We often get the impression that it has no elasticity, but in many cases the alloys present allow some "give". It's probable that the location is now weak and probably won't stand up to another hit like this without cracking, but I'm sure you already know that. BTW, kudos for thinking outside the box to make that alteration that allowed you to get going again.
#13
Hi TNC
Hi Timc
Glad you got it figured out , usually not knowing is the worst part. Agree with TNC that that spot in the case is likely weakened and will probably give again before the "modified" stud does. I was afraid of exactly this scenario, when i found that mine was not shifting to first https://www.kawasakiforums.com/forum...ar-gone-34237/ At the time, I was kind of surprised that the stud bent before the case gave out. I mention it with one of the pictures i posted in that thread.
Hi Timc
Glad you got it figured out , usually not knowing is the worst part. Agree with TNC that that spot in the case is likely weakened and will probably give again before the "modified" stud does. I was afraid of exactly this scenario, when i found that mine was not shifting to first https://www.kawasakiforums.com/forum...ar-gone-34237/ At the time, I was kind of surprised that the stud bent before the case gave out. I mention it with one of the pictures i posted in that thread.
#14
I would consider just running it like you have it now, your alternative, and really the correct way of fixing it, is obviously to swap out your crankcase. I ended up doing that on mine because of another case damage issue . https://www.kawasakiforums.com/forum...e-cases-39378/
Best of luck
Dan
Best of luck
Dan
Last edited by dan888; 08-25-2015 at 03:04 AM.
#15
Wow, this thread is giving me déjà vu. I broke two shift shafts off two days in a row in the Black Hills last fall. I posted about it here. Anyway, just like you, the MSR shift lever on my bike did not bend in the impacts - it is way too stiff. I put the stocker back on, but it bends like a pretzel at the slightest brush with a limb.
I also did some finagling with the shifter stop pin to make mostly right. I actually reused my bent pin, but clocked the bend direction using a different thickness washer. I didn't think of it at the time, but my case might well have the same condition you found: the stop pin hole not perpendicular to shift mechanism. Whether this is from crashing or machining error, could be anyone's guess.
I also did some finagling with the shifter stop pin to make mostly right. I actually reused my bent pin, but clocked the bend direction using a different thickness washer. I didn't think of it at the time, but my case might well have the same condition you found: the stop pin hole not perpendicular to shift mechanism. Whether this is from crashing or machining error, could be anyone's guess.
#16
TNC! As you mentioned, i would not have believe there was any elasticity in an aluminum case! And yes, i suspect the case is weaker there now than before...
Dan888 and Lutz - Oh my, I am not alone in this "bad luck." Dan, I never found either of your two linked posts when I was trying to figure out my issue, they would have been real helpful, sorry about your misfortune! With the bike reassembled and shifting well, I put the stock shift lever back on. As Lutz pointed out, we all had that MSR shift lever in common... but now I see the importance of being intentional about where your weakest link is!!!
I also agree that the correct fix is to replace the case, though that will be a winter project. The thought of splitting the cases and getting no performance benefit from all the work makes me think that this might be the time to do a big bore kit, just to make all the effort worth while!
Finally, how much risk do you all think there is in buying a used engine case? Would a case from a 250SF be less likely to have suffered the type of impact that damages the shifter mechanism area of the case?
TIA, and thanks for letting me know I am not the only one to go through this issue!!!
TC
Dan888 and Lutz - Oh my, I am not alone in this "bad luck." Dan, I never found either of your two linked posts when I was trying to figure out my issue, they would have been real helpful, sorry about your misfortune! With the bike reassembled and shifting well, I put the stock shift lever back on. As Lutz pointed out, we all had that MSR shift lever in common... but now I see the importance of being intentional about where your weakest link is!!!
I also agree that the correct fix is to replace the case, though that will be a winter project. The thought of splitting the cases and getting no performance benefit from all the work makes me think that this might be the time to do a big bore kit, just to make all the effort worth while!
Finally, how much risk do you all think there is in buying a used engine case? Would a case from a 250SF be less likely to have suffered the type of impact that damages the shifter mechanism area of the case?
TIA, and thanks for letting me know I am not the only one to go through this issue!!!
TC
Last edited by timc63; 08-26-2015 at 06:55 AM. Reason: fix typos
#17
...I also agree that the correct fix is to replace the case, though that will be a winter project. The thought of splitting the cases and getting no performance benefit from all the work makes me think that this might be the time to do a big bore kit, just to make all the effort worth while!
Finally, how much risk do you all think there is in buying a used engine case? Would a case from a 250SF be less likely to have suffered the type of impact that damages the shifter mechanism area of the case?
Finally, how much risk do you all think there is in buying a used engine case? Would a case from a 250SF be less likely to have suffered the type of impact that damages the shifter mechanism area of the case?
Last edited by Lutz; 08-27-2015 at 06:20 PM.
#18
Hey Lutz, thanks for the insight on that. I was beginning to feel that way after three days of trouble-free riding and shifting at the Rally in the Gorge in Hood River, OR this past weekend.
I have the stock shift lever installed now and will keep riding it through the winter to see how it behaves in the long run and will likely become very confident in it again.
It would also take a freak crash of even greater proportions than the first to transfer that much energy up to the case and pin/stud through the stock shift lever.
Of course, if I ever have the need to split the case, I'd surely replace it.
I appreciate everyone's input as it helps me sort things out from perspectives other than my own!
TC
I have the stock shift lever installed now and will keep riding it through the winter to see how it behaves in the long run and will likely become very confident in it again.
It would also take a freak crash of even greater proportions than the first to transfer that much energy up to the case and pin/stud through the stock shift lever.
Of course, if I ever have the need to split the case, I'd surely replace it.
I appreciate everyone's input as it helps me sort things out from perspectives other than my own!
TC
#19
I agree, run it until it fails, and you're right, it would be a shame to do all that work splitting cases and just bolt the same old jug back on top. Honestly the 351 is the way the bike should be from the factory.
Dan
Dan
#20
This thread ending up saving my sanity.
I had issues following a fall - see this thread: https://www.kawasakiforums.com/forum...pshifts-47399/
As I mentioned there, in the end I couldn't see any sign of damage to either the mounting boss for the centering pin, or to the gear shift shaft/pawl assembly.
But getting the pin in with the bend down was enough to get it shifting right again. So far haven't see any issues.
I had issues following a fall - see this thread: https://www.kawasakiforums.com/forum...pshifts-47399/
As I mentioned there, in the end I couldn't see any sign of damage to either the mounting boss for the centering pin, or to the gear shift shaft/pawl assembly.
But getting the pin in with the bend down was enough to get it shifting right again. So far haven't see any issues.