GSXR 1100 gearbox problem

[jmw76]

Hi Guys,

I finally managed to get my modified GSXR1100 back in my vehicle for testing.
Was at Winton today and the the gearbox decided to stop shifting for me after only about 4 or so laps. It was going great up until then.

The gearbox is now stuck in neutral and I can not shift gears. The shift lever is essentially locked solid.

There were no real nasty noises and the engine was idling smoothly when I shut it down. I had a mis shift and then I was concious that I could not change gears.

It appears that the shift barrel is jamed.

Anyone seen this symptom before?

Cheers

Peter.

:([?]

[DCRacing]

Any idea what shift you were doing, up the gears or down? from 1st to 2nd etc? The only thing i could think of would be in the selector ratchet assy, especially if the lever is locked solid. or even in the detent for the selector barrel maybe.....
There are plenty smarter people than me tho.....

[Shadowzone]

Being a constant mesh box it may be you've dropped your selector fork.

It may be a quick fix.

I know with Mack Quantum (yeah yeah it's a truck I know but a crash box is a crash box) boxes if you tried to force the gearshift it would drop the fork and have to be reconnected to the shifter. Nothing serious, but painful getting a mechanic out to do it for you. Sounds similar to your issue although you wouldn't have been trying to force the box I don't think, but it may just be something simple like that

[jmw76]

I was hoping that maybe the problem was associated with the selector ratchet area as I can get at this fairly easily by removing the clucth. Access to the detent area or the selector forks will mean removing the engine and splitting the box. A little bit more effort.
I can not really recall whether I was changing up or down. I think it might have been on a down shift.
All I know now is that the shift lever is locked solid and the box is in neutral.
I could probably force the lever but I have not tried yet.
Does anyone know of a situation where a selector fork has somehow become disengaged with the shift barrel?

[Deano]

pull the clutch off first and have a look at the detent set up.

could be a stuck pawl in the ratchet or something very simple

dont force anything cause you will just break stuff

[80s freak]

Wot ^^^^^ he says. sounds selector/shift drum external rather than actual g'box to me.

[jmw76]

Well, stripped the box today.
Not good.

I guess the 6 speed that I had carefully rebuilt, just was not up to the power of my 1196 engine.
A rather strange mode of failure really.
I suspect that the failure of the 5th gear drive dog, probably caused the catastrophic failure of 1st gear.
I wasn't using first gear at the time.
Back to a 5 speed again, I guess.

Cheers.

http://www.asfphotos.com/upload/1256432964.jpg


http://www.asfphotos.com/upload/1256391187.jpg

[megareg]

I'm speechless...... a Suzuki gearbox failing like that!!!

I was thinking it might have been one of them pawls jammed, but no, worse than that....

When I was in Mining, I used to work with a bloke that used to be a spanner for a NZ Suzuki team that was racing a Kat in one of the Castrol 6 hour races at Oran park, I showed him one of my spare transmissions I was going to use for my OMG Kat motor build, his comments were to "just grind a bit off here with a dremel and MAKE SURE THE DOGS ENGAGE EVENLY" he stressed that although it was a used transmission and a couple of dogs had some wear, as long as the dogs engaged evenly it was fine, but I'm sure you did this on the build of it, thankfully, it was not more catastrophic, like ventilating cases and/or spitting you down the track.

[80s freak]

Haven't seen one of those two piece gears in ages. heehee.

[DCRacing]

Hmmm i am quite suprised at that sort of failure in the box...... maybe with the added load of a cart it wasn't up to it.......... I run a 6 spd in the race bike but have had no issues....

[Deano]

seen one in about 5 pieces before but not broken straight through.

the dogs look bout knackered on that gear anyway

[jmw76]

I know that the drive dogs all look pretty shagged now.
I can assure you that when the gears were installed, only 4 or so events earlier (<400km), they were all freshly undercut to make it strong enough to survive the punishment of racing. I guess the theory was good, but in practise the 6 speed gear set is inherently much weaker. The smaller gap between gears also makes it easier for a slight mishap to cause incorrect gears to engage.

I think with the dog assembly between 4th and 5th failing that has slammed the 5th gear into 1st and just blown it apart.

Peter.