yzf 450 10 gearbox broke!

[ellisde]

hallo,

after 40 std my gearbox broke! first i opend the clutsh but it was perfekt, let th eoil out an found a pice of the gearbox tooth!

i cant believ it,how is this possible,does anyone have had the same prob?

will post pics later,tonight im opening the engine!

mfg sebastian

Edited October 18, 2010 by ellisde

[gfmoto]

yeah my buddy lost 2nd gear I hear the trannys demand the clutch to shift or you will pay the price for being lazy! Also the GYTR air filters are a must and change them often or your valves will suffer!

[csagstrom]

some have hade the same issue over here in sweden but the cause has always been violent shifting, the gearbox just can´t take it! happened to a friend and me but i replaced the gears before they broke... you just have to addapt your riding style and be a bit more gentler on the box! Good luck fixing it, and hope you enjoy your awesome bike ?

[ellisde]

my mechanik opend the engine last night and: 2end gear is broken and the one next to it! havent seen it yet, but he said it looked exploded! some more things in the gearbox need to be done , lager und simmerringe. the piston ,cylinder an timing chain are dead too.the rest is perfekt.?

i wonder how this could happend? my mechanik said the gears are too thin???

@csagstrom whtas violent shifting? i dont know the word

[HRC]

Wow ! Yamaha seems to have had problem with the gearbox the last ten years on their 4-strokers ! I remember my dad had problems on his YZ426F back in 2001 !

I thought Yamaha had taken care of those problems by now ! ?

[ellisde]

off topic,where can i buy oem yamaha parts in the usa,do u have a link for me?

vielen dank!

[kawamaha]

@csagstrom whtas violent shifting? i dont know the word

wörtlich: gewaltsames schalten ?

[Peetu]

off topic,where can i buy oem yamaha parts in the usa,do u have a link for me?

vielen dank!

I bought couple weeks ago there: http://www.cyclepartswarehouse.com/

Cheap parts and fast delivery. They don't send order confirmation so remember print it, when you have finished an order.

[ellisde]

wörtlich: gewaltsames schalten ?

ok,danke!

jetzt weiß ich ,daß ich nicht alleine bin mit dem prob ,bei uns in D findet man ja keinen der ähnliche fehler hat bzw diese zugibt!

grüße

[ellisde]

@peetu thanks

[grayracer513]

Wow ! Yamaha seems to have had problem with the gearbox the last ten years on their 4-strokers ! I remember my dad had problems on his YZ426F back in 2001 !

I thought Yamaha had taken care of those problems by now ! ?

No one I know has personally broken one. In fact, I have never broken a gearbox in any bike, including some that actually were weaker than they should have been. I use the clutch, but not always. What I don't do is shift under a lot of power, or make high speed downshifts without either the clutch or a blip of throttle to unload things. My son, who I taught to ride, and who thrashes his bike as hard as anyone, hasn't had one fail either.

The big YZF trans was originally imported from the YZ250, and was used with minor ratio and pitch changes through 2002. The first generation 450's got a 4 speed with wider gears and beefed up shafts. People nevertheless managed to break them occasionally. When the Gen2 engine came out in '06, the 450 got a new 5 speed that is 12mm wider overall than the Gen1 was, but still people figure out how to break them. People break everything else, too.

IMO, it's more the rider than the bike. Yamaha could make the trans indestructible, but there would be a weight penalty.

[BBrown626]

I broke 3rd gear in my 04 450. It tore the gearbox up! I had to replace the cases and several gears. My '08 YZ250 bent a shift fork after about 10 hours, but I didn't have any more problems over about 200 hrs of operation.

I took the Champ Factory course with Tortelli a few months back. He trains people to NOT use the clutch for shifting. He teaches people to hammer it into gear without even backing off the throttle: "it can take it" he said. My mechanic doesn't rebuild my bike and the KTM factory shop doesn't give me my parts. I fan the clutch or back off the throttle!

[ellisde]

i still wonder why it happend?it was after a doppel sprung.

-mybe i got on the shifter when i got on the ground

someone who stand next to me when it happend said,i heard like the chain hit the bike when i landed..if this was the case,it shifted the gearbox in a between gear and this does no gearbox like...

not good to do a mistake without to know the reason,now it will be allways in my head ?

[brentn]

No one I know has personally broken one. In fact, I have never broken a gearbox in any bike, including some that actually were weaker than they should have been. I use the clutch, but not always. What I don't do is shift under a lot of power, or make high speed downshifts without either the clutch or a blip of throttle to unload things. My son, who I taught to ride, and who thrashes his bike as hard as anyone, hasn't had one fail either.

The big YZF trans was originally imported from the YZ250, and was used with minor ratio and pitch changes through 2002. The first generation 450's got a 4 speed with wider gears and beefed up shafts. People nevertheless managed to break them occasionally. When the Gen2 engine came out in '06, the 450 got a new 5 speed that is 12mm wider overall than the Gen1 was, but still people figure out how to break them. People break everything else, too.

IMO, it's more the rider than the bike. Yamaha could make the trans indestructible, but there would be a weight penalty.

High speed downshifting can ruin a tranny without clutch use? I always thought it would be damaging if you up shifted under load without the clutch..

I always down shift without the clutch... maybe I should change my ways.. Last thing I need is a broken bottom end at only 40 hours.. I already have 18 on mine.

[grayracer513]

High speed downshifting can ruin a tranny without clutch use?

...or a blip of throttle to unload things.

Depends on how fast you're going relative to the gear you're shifting into, also.

It's also worth realizing that there are some people who can ? up an anvil.

[BlakJak]

It's also worth realizing that there are some people who can ? up an anvil.

?

[ellisde]

got the new gears, and they are differnt colour an they loock stabler.the colour is dark black,i think they are diffrent hadenend! ...forgot to take pics,sorry

[Polar_Bus]

9 different motocross bikes, Hon, Yam, Kawi, 4 different street bikes, and 1 shifter kart spanning the past 31 years of typical gearbox abuse without a single transmission /gear failure. Am I doing something wrong ? ?

[brentn]

Holy crap this thread sucks. We have ZERO pictures on ANYTHING that broke to at least give us an idea of any kind of design flaws for the 2010 gearbox. Then we get a post about a new transmission that looks different, possibly case hardened compared to the original??? And again, ZERO pictures.

COMPLETE FAIL

??

[grayracer513]

Sorry to see that it failed to meet with your high standards of excellence.

As far as the "design flaw" is concerned, the '10/'11 gearbox is 85% the same as the '06-'09 trans, part numbers and all, except for 3-4 upgraded numbers.