4th gear problem

Hello everyone first post here.  I bought a 2011 Wr250r 2 weeks ago with 11k miles, I put about 1300 awesome miles on it since.  I was riding today at Hollister Hills and when I shifted into 4th and let the clutch out the transmission sounded awful.  I can gear this grinding/rattling noise but only in 4th.  Bike has been shifting great never any problems prior since I owned it.  Gonna buy a service manual and possiby pull the motor to split the casese.  Anyone get into their tranny yet?

Edit 10/4

Rode it on the street after adjusting the chain, checking rollers, checking sliders, and lubing the chain. 4th gear still has a loud chatter/vibration. 5th and 6th gear are good

Drained the oil, no metal chunks or any signs of metal.

Have a service manual, hoping I am overlooking an easy fix and not looking forward to pulling the motor

3 teeth broke off total, 2 in one section and one more on the same gear about 120 degrees from the first. Gonna make sure nothing is bent then install new parts and put it all back together.

How do you break off teeth in the fourth gear?? I have seen damaged teeth for the first gear in an R6, dude downshifted into first still doing 130+ km/h

Damn that sucks but at least you found it. That is not a common problem at all so who knows, maybe that gear had a defect...

Nothing seems bend, shifts as usual you say. No locking symptoms.
For sure inspect on cracked casing.
When locked it will be wedged and cracked.
Once had 2 tooth missing on a tranny, tooth just dropped, no harm.

The bike was shifting into 4th and out of fourth great just once I let the clutch out it would chatter and vibrate. Probably gonna buy a 3rd gear also since that one is touching 4th

banshee01 wrote:

The bike was shifting into 4th and out of fourth great just once I let the clutch out it would chatter and vibrate.  Probably gonna buy a 3rd gear also since that one is touching 4th

I have no doubt those chunks of gear are sitting in your oil pan. You are lucky they did not cause more damage!

This is something--please post an update on how it's running when you get it back together.

-morgan

CRFan1 wrote:

banshee01 wrote:

The bike was shifting into 4th and out of fourth great just once I let the clutch out it would chatter and vibrate.  Probably gonna buy a 3rd gear also since that one is touching 4th

I have no doubt those chunks of gear are sitting in your oil pan.  You are lucky they did not cause more damage!

I found them as soon as I split the cases and yes lucky they did not cause more damage in there

morgan9283 wrote:

This is something--please post an update on how it's running when you get it back together.

-morgan

Will do, I decided to order the 3rd gear pinion which is meshed with the 4th gear in the tranny. the 3rd gear pinion had some visible wear on it from 4th gear breaking. I think it is going to be another 8 days for me to recieve the 3rd gear pinon from japan. I was not able to locate any tranny parts here in the us. I will probably be puting it all together nov 5th and 6th.

Have the bike back together, fired right up and sounds good. Will ride tomorrow