need help MY 08 Busa gearbox destroyed

[Aly Kabil]

Hello everyone

i decided to open my engine to learn how everything is working inside after i rebuild the engine i took the bike for a few rides and everything was fine and one time i was driving on 280km/h on the 5th gear and wanted to shift for the 6th with the quick-shifter the dashboard shows 6th gear but the engine start cutting out like it is on neutral i downshift again for the 5th it was no problem when i shift back to 6th it do the same then i downshift again to stop the bike and its stuck on the 3rd, 4th, and 5th i cant shift for 2nd or 1st or neutral, i went back to garage and i put the bike on the rear stand and tried to move the tire by my hand to get it to neutral and the gear indicator is getting crazy jumping from 5th to 2nd to 5th to 4th and when i turn the tyre back its stop coz of the gear but if i push it in the driving direction strongly it start to move hardly then easy, i open the engine and i found the 3rd 4th and 6th gear locking pins are worn and the 2nd driven sprocket not in good looking and it have strong play coz of the ring drive shaft friction is destroyed and i found some of it already in the oil pan like rubber parts... can you please help and tell me what is the reason of all these damages or what i did wrong when i rebuild my engine or its something normal for all the busas as i read a lot of forums that it can happen

thanks in advance for help and here are some photos and link for video

 

[GIXERHP]

The scoring on the forks is from the gears being pushed on, IE some one that rides there foot on the shifter. As for the rest of the tranny,, send it off and have a tranny shop repair and replace what is needed

 

[Aly Kabil]

The scoring on the forks is from the gears being pushed on, IE some one that rides there foot on the shifter. As for the rest of the tranny,, send it off and have a tranny shop repair and replace what is needed

Thanks for reply
Do you think the reason can be that the shifter lever was not adjusted correctly?? Coz am trying to find the reason and on this day at the morning I was trying to adjust the lever on Vortex rearset and I was late so I move it one hole up and decided when I will be back I will adjust it to for better way coz I didn’t feel comfortable while shifting that the lever is too high for the normal position

 

[TIMMYDUCK]

The guy Gixerhp that replied is to your thread " IS " the guy , when it comes to Hayabusa transmission repair.

What he said is dead on balls perfect.

It most certainly isn't because you had the shifter on a different tooth.

 

[Aly Kabil]

The guy Gixerhp that replied is to your thread " IS " the guy , when it comes to Hayabusa transmission repair.

What he said is dead on balls perfect.

It most certainly isn't because you had the shifter on a different tooth.

ok am agree with you but am still trying to figure out the reason coz am not putting my foot on the shifter while am driving so what can be the reason... do you think it can be the balancer gear was not adjusted correctly when i rebuilt my engine??

 

[mjl3truck]

Wow I thought I was hard on transmissions! In my limited experience there is not too much to screw up when putting the transmission together if you pay attention and follow the manual. When you split the cases the first time did you disassemble all the gears off the shafts and inspect them along with the thrust washers? It is easy to miss wear/damage unless you inspect each part. So you may have set your self up for failure reusing worn parts. If I was looking at the parts without knowing the history I'd go with some form of abuse such as riding the shifter, not having the settings correct on your Q/S, having an intermittent Q/S but you just shift it anyway.

 

[Aly Kabil]

Wow I thought I was hard on transmissions! In my limited experience there is not too much to screw up when putting the transmission together if you pay attention and follow the manual. When you split the cases the first time did you disassemble all the gears off the shafts and inspect them along with the thrust washers? It is easy to miss wear/damage unless you inspect each part. So you may have set your self up for failure reusing worn parts. If I was looking at the parts without knowing the history I'd go with some form of abuse such as riding the shifter, not having the settings correct on your Q/S, having an intermittent Q/S but you just shift it anyway.

No I didn’t remove the sprockets from the shafts I just removed the shafts with the sprockets on it to clean the crank case and put them back and I have no problem with the Q/S am already using it from 6 years ago with no problem at all

 

[justintime2]

Here’s an idea, don’t open up a motor and play around with things you aren’t familiar with so you can “learn”.

 

[Aly Kabil]

Thnx for the advice but actually it’s too late looool and am trying to learn now from my mistakes and trying discover what I did wrong

 

[Aly Kabil]

No one can tell me what can be the reason to destroy the gearbox like this except that I was putting my foot on the gear lever while driving??

 

[POWERHOUSE]

You put it back together wrong that’s what happened you need a new mechanic to do the job right

 

[michael parris heuberger]

You put it back together wrong that’s what happened you need a new mechanic to do the job right

You put it back together wrong that’s what happened you need a new mechanic to do the job right

Hi. Like Frank said you need some one to to the job right. And Frank is the man for the job. He can fix it better then new!

 

[David Offor]

I’ve never stripped out a transmission or any other major component before, just to see, ‘how it works’, that’s asking for trouble but from your description, I’d be thinking, something was left out, maybe a thrust washer?
I’ts only a rough guess, It’s always nice to know the reason, for the problem.

 

[Aly Kabil]

I’ve never stripped out a transmission or any other major component before, just to see, ‘how it works’, that’s asking for trouble but from your description, I’d be thinking, something was left out, maybe a thrust washer?
I’ts only a rough guess, It’s always nice to know the reason, for the problem.

Thnx for the advice but actually nothing was left outside everything was installed but till now I don’t have confirmed reason for what happened but am still trying to figure out

 

[202mphbusa]

Here’s an idea, don’t open up a motor and play around with things you aren’t familiar with so you can “learn”.

WOW I would have never learned anything then

 

[David Offor]

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.

 

[202mphbusa]

I keep preaching
FOLLOW THE MANUAL ONE STEP AT A TIME
and there is little that most people can not do

 

[justintime2]

Here’s an idea, don’t open up a motor and play around with things you aren’t familiar with so you can “learn”.

WOW I would have never learned anything then

Great if it’s a machine you can afford to learn on, that does not however appear to be the circumstance he now finds himself in...

 

[Mythos]

WOW I would have never learned anything then

Mistakes can be costly but so far in ten years of wrenching on these bikes, I've saved a ton of money learning it myself. When it comes to anything inside the motor, I'm painstaking about observing and photo documenting everything....and I get a thread going for advice as I go through the process. I often take 10X as long as a pro but I know it's perfect and I know how to do it next time + I can help others. If you take an interest, wrenching can be a great part of owning these machines.

 

[Mythos]

i was driving on 280km/h on the 5th gear and wanted to shift for the 6th with the quick-shifter the dashboard shows 6th gear but the engine start cutting out like it is on neutral i downshift again for the 5th it was no problem when i shift back to 6th it do the same then i downshift again to stop the bike and its stuck on the 3rd, 4th, and 5th i cant shift for 2nd or 1st or neutral

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.

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.