Welcome to the 02 tranny failure club. Ive already replaced mine, 3rd gear split in two, took out 1st, 4th, and 5th. I have little confidence mine will last for the life of the quad. Im seriously going to look at the 450R. The 400ex I own, although not used much has zero problems along with a bunch of ex owners I personally know. My buddy's 02 Raptor starter went out two weeks ago, I guess thats next with mine.

 

Yep - See this post Selection ?

 

Which side of the 2nd gear pinion was it? for 4th or 5th.

I must say this is a fluke, the first ever failure I have heard involving this area of the trans. I have heard of exactly 3 2002 trans failures in the last year, yours is the 4th. 2 of the previous failures I saw were the 3rd gear wheel splitting or chucking its teeth, one was put together wrong and then there is yours.

the area yours failed is for either 4th or 5th gear which is really odd.

I know you said the shiftforks were changed but was the 2002 shift fork used for shift fork 2? there is very little difference to this shift fork from the previous year, if held up together it would be very hard to tell the difference between the years. The 2001 shift fork would fit the 2nd gear pinion with too much clearance between the forks tines. I messed up and put these 2 shift forks together without marking them and it took me a good 20 minutes to figure out what changed and why I had to use the new. The 2002 is marked with a "10" like how the part number changed "10" shiftforks

 

You can weld the shift fork in the "U" part of the of the fork to add a pad to make the gear ingauge all the way every time. From what I have seen people miss a shift a few time and the don't get it all the way into gear and after that they brake.

 

Fisher,
I was just wondering, do you thing that cryo treating the gears could of had something to do with the failure? I don't know exactly how cryo works, but doesn't it make metal harder so it doesn't wear out as soon? But harder metals are more likely to crack and break aren't they? So this could have beent the reason the gear just split in two?

Also it seems like that was the only difference between your gear set and others is that you had them cryo treated.

I know that the metal parts that are cryo treated we use on the farm last much longer because they don't wear out. But on the other had if you drop them on the cement they will shatter because the metal is so hard.

I just thought I would through that idea out there for you as a possible reason of the failure.

 

I'm quite sure it's the 2002 shift fork but I'll have to look at it and make sure it's got the "10" on it. I remember paying lots of attention to those details back when I did the conversion.

The side of the gear that has three dogs is the side that busted. The other side of the gear has 4 dogs and that side is OK. I cant visualize if it's the 4th or 5th. Unfortunately, it's not in front of me now....

Cryo - I dont know if it helped or hurt. Maybe it lasted a bit longer since it was cryoed ? or - it made it brittle ? The race car guys that cryo their gears swear by it (I researched it quite a bit). I dont know either way.

 

I couldnt either, I know one side has 4. Probably not too important which side, just for future reference.

 

The side with the 3 dogs mates to the 4th pinion gear

 

Mike,

I checked - I do have the correct shift fork - marked "10". It shows little or no wear anywhere !

Also, found a big crack in the subframe and one up by the carbs. Then, I was mounting a new knobby on my bike and pinched the tube -

Jeez - Hit a guy when he's down !? I turned off the lights and got a beer.....

 

a guy came in to the shop the other day with a 02 rap. he had a 690 with all the goods and had his tran go out. it's doing the same thing mine did when it went out. 2nd gear has a bad slip to it. that is no good at all!!![img]i/expressions/face-icon-small-mad.gif[/img]