need help MY 08 Busa gearbox destroyed

[ali123]

Obviously I would give you some advice about gearbox assembly if I knew. Sorry, no such wisdon to impart to you but I do have a bit of experience with an aftermarket quickshifter. The one I use on my ZX-14 (HM Plus) doesn't work very well at high rpm unless you use a very slow kill time. It has produced behavior with upshifts EXACTLY as you have described. ---clutchless shift up, does not engage the next gear, engine spins like in Neutral. The gear position arm does not have enough kill time to climb over the lobe on the shift cam (star) and it apparently hangs up on the lobe putting the transmission in NO gear. After a few hangups like that, a missed shift now results in the transmission slamming back to the previous gear. Needless to say, I'm hesitant to use the quickshifter under hard load until I can figure out some way to preset proper kill times for gear and rpm.
View attachment 1580651
Let me ask, have you had similar experience with your quickshifter? After missing a gear and a second or two passes, it can be very difficult to judge the proper rpm to blip to execute a smooth downshift. I slammed my gearbox a few times after a missed shift. I got metal slivers like I see in your photo. They came out in the oil change and magnetic oil drain plug. For now, I don't dare use my quickshifter over 8k rpm.

What I'm saying is that this could be a simple case of doing a terrible downshift at high rpm. That might have broken something.

Sorry. I wish I had a lot more knowledge of gearboxes. I might be able to tell you what broke and we would have a better idea if the quickshifter/bad downshift theory is correct. Seems possible especially if you experienced clutchless shift problems before the rebuild.

if ure pulling metal out of the oil pan... u might wanna seriously consider doing some upgrades... perfect time to pull engine out yourself and bring it to a great engine builder... for a few grand ull have a rocketship... high comp pistons/headwork/new bearings and rings....

 

[Mythos]

for a few grand ull have a rocketship... high comp pistons/headwork/new bearings and rings....

You don't have to look at this as, "I broke my bike." You can look at it as, "I wore my bike out a little and now I will make it better and more badass than ever!"

 

[ali123]

You don't have to look at this as, "I broke my bike." You can look at it as, "I wore my bike out a little and now I will make it better and more badass than ever!"

and honestly for the money u pay... having a pro build your motor and set everything up.... IMPROVE it... they do this for a living.... think about it.. could an AMATEUR do YOUR job as well as you do it? Probably not, right? On top of all the other benefits.... IF ANYTHING goes wrong... there is someone to talk to and stand behind it all.... engine builders have secrets that they aren't telling ANYONE.... pay the man.

 

[jermzfree]

Are those the 5th/6th gears in the video with the destroyed dogs? Also why is that one gear loose on the shaft? Missing c clip or something broken? Improper down shifting to 5th after hitting a false neutral might be to blame here.

 

[Aly Kabil]

Selector forks put in ‘back to front’/wrong?
If you had nothing left over, it would point too, something either not aligned correctly or a component put back in, in the wrong position.
If you don’t separate the gears and shafts, there’s not a lot you can get wrong on transmissions.

Exactly am agree with you about separating the transmission I didn’t touch it and when I remove it 2nd time everything was in the right place the only strange thing that this gear which is loose in the video I t

Obviously I would give you some advice about gearbox assembly if I knew. Sorry, no such wisdon to impart to you but I do have a bit of experience with an aftermarket quickshifter. The one I use on my ZX-14 (HM Plus) doesn't work very well at high rpm unless you use a very slow kill time. It has produced behavior with upshifts EXACTLY as you have described. ---clutchless shift up, does not engage the next gear, engine spins like in Neutral. The gear position arm does not have enough kill time to climb over the lobe on the shift cam (star) and it apparently hangs up on the lobe putting the transmission in NO gear. After a few hangups like that, a missed shift now results in the transmission slamming back to the previous gear. Needless to say, I'm hesitant to use the quickshifter under hard load until I can figure out some way to preset proper kill times for gear and rpm.
View attachment 1580651
Let me ask, have you had similar experience with your quickshifter? After missing a gear and a second or two passes, it can be very difficult to judge the proper rpm to blip to execute a smooth downshift. I slammed my gearbox a few times after a missed shift. I got metal slivers like I see in your photo. They came out in the oil change and magnetic oil drain plug. For now, I don't dare use my quickshifter over 8k rpm.

What I'm saying is that this could be a simple case of doing a terrible downshift at high rpm. That might have broken something.

Sorry. I wish I had a lot more knowledge of gearboxes. I might be able to tell you what broke and we would have a better idea if the quickshifter/bad downshift theory is correct. Seems possible especially if you experienced clutchless shift problems before the rebuild.

thanks so much for sharing the information about what you had before specially from the quickshifter but I have been using this quickshifter dynojet for almost 6 years without any problem even before I open my engine and after also I was working normally like before, I don’t know maybe I did something wrong while assembling but I was following the manual step by step and am sure I didn’t miss any step

 

[Aly Kabil]

Are those the 5th/6th gears in the video with the destroyed dogs? Also why is that one gear loose on the shaft? Missing c clip or something broken? Improper down shifting to 5th after hitting a false neutral might be to blame here.

No they are the 3rd/4th and the 6th gear and this loose gear i thought that the clip jusmped out from place or the bushing is broken but I removed all the parts now and I found the most strange thing at least for me that the bushing moved half awy from the gear and stuck to the gear that even the gear is not rotating around it and they both stuck as one part and it push the clip to be bend but still staying in its place and when I remove this gear out to try to return the bushing to normal place it didn’t move at all and I have to push it out with vise to remove it from the gear like I remove bearing it was stuck so badly and still don’t know what can make it stuck like this special that it’s the last gear on the shaft and I didn’t touch it while assembling the engine

 

[jermzfree]

Take the transmission to a specialist to examine, replace parts, and reassemble. When you seal the cases back together, be mindful to use the right amount of sealant so not to block oil passages.

 

[jermzfree]

And get 2nd gear undercut while you are at it!

 

[Aly Kabil]

Take the transmission to a specialist to examine, replace parts, and reassemble. When you seal the cases back together, be mindful to use the right amount of sealant so not to block oil passages.

Thnx I did and he said the gears have to be changed it can not be undercut and about the sealant I was so carful last time when I did it to not block the oil passages

 

[michael parris heuberger]

Thnx I did and he said the gears have to be changed it can not be undercut and about the sealant I was so carful last time when I did it to not block the oil passages

Hi.Aly. The under cut does not fix a bad gear. You undercut even a NEW gear it makes it shift better. If there is no race shops that KNOW what they are doing DO NOT let them touch it. Send it to Frank at Powerhouse 111 Jersey St West Babylon NY. 11704. It will come back way better than new. Also send him your ECU for a reflash it will feel like a way better bike!

 

[Aly Kabil]

Hi.Aly. The under cut does not fix a bad gear. You undercut even a NEW gear it makes it shift better. If there is no race shops that KNOW what they are doing DO NOT let them touch it. Send it to Frank at Powerhouse 111 Jersey St West Babylon NY. 11704. It will come back way better than new. Also send him your ECU for a reflash it will feel like a way better bike!

Thanks Michael but unfortunately I live in Poland now not in the US

 

[ali123]

just look for a used tranny... and don't split this one open

 

[Aly Kabil]

just look for a used tranny... and don't split this one open

I did already, I ordered used one from USA

 

[ali123]

I did already, I ordered used one from USA

hope "she" didn't cost too much

 

[Aly Kabil]

Unfortunately it did 720$ with shipping to Poland

 

[Aly Kabil]

Hey Everyone

Tomorrow i will start bulinding my engine again i just recieved the transmission from USA, i will keeP following the manual step by step but i will be so thankful if anyone will tell me some tips or tricks what i should know to prevent having the same problem again with the gear box

Thanks in advance for any help

 

[Aly Kabil]

Hey everyone

I think I know what is the reason but to make sure I would like to ask if some one can answer my question coz nothing is mentioned about it in the service manual

Does the C ring what is installed in the upper case groves in the counter shaft to rest in it have direction or it doesn’t matter coz I see that it have so small rounded shape from the right and left side but from the middle it’s the same??

Thanks in advance

 

[jermzfree]

The flat sharp edge side of the c clip is what you want pressing up against the gear. In general that's how c clips go.

 

[Aly Kabil]

The flat sharp edge side of the c clip is what you want pressing up against the gear. In general that's how c clips go.

Thanks a lot so the rounded side shout be facing the clutch and the sharp one facing the transmission

 

[jermzfree]

I'm not sure without seeing a picture, but in general the flat side goes against the mounting surface