gsxr400 gk76a gearbox - 2nd gear noise

[NHGk76a]

Hi guys
Theres a clunking /knocking noise out of gearbox when second gear engaged ,also very slight in first and neutral.
I suspect teeth missing off second gear ....
Has anyone got pictures of a gearbox split or engine out with gear cluster visable ???
Iv had bike a couple of years now and if it wasnt for the info of this site i would of burned my bike ..Thanks everyone....
When its running right its a TROUSER FIREWORK Anyways if it is just second any ideas were i could buy second gear or complete cluster ???

[Marsbar]

My gears clunk when i first engage, or is it constant noise when in that gear?

I have a spare gearbox laying around, i think it has all pieces, if not got a spare engine i could strip. I got a few pics of different gearboxes ive head, dont really know what you are looking at in particular?

[SevenThreeSeven]

Here's a video that somebody made. It does a great job demonstrating how motorcycle gearboxes operate. https://www.youtube.com/watch?v=SYYZf1HW8xA

This might help you visualize what's happening inside your GSXR's gearbox. It's a complex situation in there.

Further, in this video https://www.youtube.com/watch?v=1Tdo8rFeBgg if you go to 1:14:10 the guy is holding in his hand the fixed-sliding gear that selects 2nd and 6th gears. As he turns it over in his hand you get to see both sides of this gear and you can easily see that the "dogs" on the 2nd gear side are damaged. This is a common problem on sport and super-sport bikes that have been ridden/owned by "boy racers" who really enjoy slam-shifting the gearbox from 1st into 2nd when they accelerate from an intersection or other stopped situation.

[NHGk76a]

Thanks that was great help
I was also wondering would you know were i could get 2nd on it own With syncro rings if they even have synkro rings ?? Or would you sell a gear cluster and the part that effects selecting neutral ??
Thanks again

[SevenThreeSeven]

were i could get 2nd on it own With syncro rings if they even have syncro rings ??

All motorcycle gearboxes are constant-mesh "dog-boxes", they don't have any synchronizing rings. There are three types of gears inside a motorcycle box: fixed, sliding-fixed and freewheeling. The 2nd+6th cog that is probably your problem is one of the sliding-fixed gears.

The process of getting your gearbox properly sorted will end up being an educational experience. You're going to end up knowing a bunch about motorcycle gearboxes.

I think you'll probably have to go to Ebay (or a similar website) to buy either a complete shaft or a whole gearbox from a parted-out bike. But remember, this 2nd+6th cog is the most often damaged piece in these gearboxes, so finding one in perfect condition might be difficult.