2000 yz426 trans question's with pics.


20 replies to this topic
  • thumpinscott

Posted May 23, 2004 - 01:32 PM

#1

My 5th gear was slipping a little bit, not enough to come apart, but enough for me to split the case. There was absolutely no loose metal in the case. The gears all look good except for a little wear on the dogs shown below. The other problem is some rub marks on the shift fork. Is there enough wear on this gear to cause the 'slip?' How do I know if the wear on the fork is from a bent fork or something else? I'm thinking that as 5th gear popped out it pushed on the fork causing the wear.

Posted Image
Posted Image

Posted Image

  • YZ400Court

Posted May 23, 2004 - 01:59 PM

#2

I had similar problems and rather than trying to decide which part to replace, I just replaced all forks and worn gears. My problem turned out to be a bent fork, obvios when I got the new ones and put them side by side, but I still replaced all worn gears also.Shift forks retail at about 40 bucks, gears between 30 and 40.

  • Squirly246

Posted May 23, 2004 - 02:07 PM

#3

Scott, I have my 426 apart as we speak. I was not having any shifting problems, my gear and shift fork look almost identicle to yours(that does not mean it is not your problem though). I would also check the shift segment/stopper lever as this acts as a detent and also helps hold the shift cam in the correct gear. Let me know if a can help in any way(show some pictures of mine ect). It's an eary feeling when your bike is this far apart and you want to make sure it is right when it go's back together. Have a great day.

  • TonyDeCoster

Posted May 23, 2004 - 05:57 PM

#4

That is a perfect example of a bent shift fork. I would check the shift drum as well for wear in the grooves and at the "corners". If any of the other shift forks have simolar wear, replace them too. And check all the gears for wear on the dogs. No sense in going in there again if you can avoid it.

  • YAMAKAZE

Posted May 24, 2004 - 02:50 AM

#5

Ditto what Tony said. I have seen this several times in the last few years. The good news here is that the shift fork is made of softer material than the drum and chances of drum damage from the fork is very rare.

By the way... The gears look fine.

Bonzai :thumbsup:

  • thumpinscott

Posted May 24, 2004 - 03:24 AM

#6

...... chances of drum damage from the fork is very rare.

By the way... The gears look fine.

Bonzai :thumbsup:


I thought that the gears looked fine too, but wasn't sure. The drum has no visable wear. I'm pretty happy that there wasn't anything really bad in there, but I would like to see something that really stands out. If it's as simple as a bent fork, then it will be a snap to get it back together and running again.

  • TonyDeCoster

Posted May 24, 2004 - 02:46 PM

#7

With all due respect, those gears are worn and should be replaced. Looking at the dogs, there is visable wear on both. Any gears in the tranny with similar wear need to go. Pay special attention to second, third and fourth as they take the most abuse. Can you post some closeup pics of the drum? They often show signs of wear at the corners of the grooves where the shift fork guide pins ride. I've seen some that were OK but more often than not, there is visable wear.

  • grayracer513

Posted May 24, 2004 - 03:20 PM

#8

Gears do not slip. They will become hard to shift, jump out of gear under a load, fall out of gear when the load is released, grind when shifting, howl, or break teeth and knock, but they won't slip, at least not more than once, as they are exploding. Clutches slip, and a clutch that is losing it's grip will show up in the highest gears first, 'cause that's where the most load is placed on them.

The wear at the center ot the shift fork suggests that it is bent, particularly if the little crescent mark that it shows is only on one side. In the second picture, the focus is a little soft, but it looks like the near side of the dog at 3 o'clock is rather heavily bashed in. If that is the case, the wear tells me that it isn't engaging the sliding gear next to it as far as it should, which would be due to the bent fork. The wear mark should extend farther down the dog closer to the gear itself. That gear, and the one it locks against (not meshes with) should be replaced.

When you say slip, what exactly was the bike doing?

  • thumpinscott

Posted May 25, 2004 - 03:42 AM

#9

It was not the clutch, It would do it at any rpm or 'load' in 5th gear only. It would be better descriped as a skipping than a slipping, but the rpms would jump up for a fraction of a second, every few seconds. The dogs have the little rounded corners, most likely from the percussion caused by skipping, due to the bent fork not fully engaging the dog and it's corresponding gear. I think that I will replace that gear, it's corresponding gear and the forks. It's better to be safe than sorry, and it's only about $40 per gear.

  • thumpinscott

Posted November 09, 2004 - 03:05 PM

#10

Ok, now I am very sick. I just got my bike all back together. I ended up doing the cam mod, bk carb mod, and a new top end while I was in there. It runs perfectly, except for the 5th gear.

All that work and it's still skipping in 5th. The drum was fine, I replaced the gears and shift forks, everything was tight and clean and it's still skipping. I wanna burn the stupid thing. I don't know what to do now? Someone help me.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • John_Lorenz

Posted November 09, 2004 - 03:13 PM

#11

Ok, now I am very sick. I just got my bike all back together. I ended up doing the cam mod, bk carb mod, and a new top end while I was in there. It runs perfectly, except for the 5th gear.

All that work and it's still skipping in 5th. The drum was fine, I replaced the gears and shift forks, everything was tight and clean and it's still skipping. I wanna burn the stupid thing. I don't know what to do now? Someone help me.


My 00 did this until I realized my foot was catching the shifter a little causing it to skip, I have moved the shift lever up a few slots and as well as do the Peg Mod to lower the Peg down and away form the shifter. It dont happen any more :cry:

  • tool

Posted November 09, 2004 - 05:40 PM

#12



Quote:
--------------------------------------------------------------------------------

Ok, now I am very sick. I just got my bike all back together. I ended up doing the cam mod, bk carb mod, and a new top end while I was in there. It runs perfectly, except for the 5th gear.

All that work and it's still skipping in 5th. The drum was fine, I replaced the gears and shift forks, everything was tight and clean and it's still skipping. I wanna burn the stupid thing. I don't know what to do now? Someone help me.


--------------------------------------------------------------------------------



My 00 did this until I realized my foot was catching the shifter a little causing it to skip, I have moved the shift lever up a few slots and as well as do the Peg Mod to lower the Peg down and away form the shifter. It dont happen any more



i dont think its his boot hitting the shifter. but i feel your pain man, my 00 has had nothin but trans problems and cb key problems. if i were you, after rebuilding it and everything, i would just gear it tall and ride it like a 4 speed. or sell it for practically nothing. :cry:
your dillema boggles the mind. :cry:

  • thumpinscott

Posted November 09, 2004 - 05:57 PM

#13

I wish it was as easy as my foot on the shifter. I would rather fix it, but don't know what to do now. What about the external shifting mechanism? Is there something that can go wrong in it? Somebody said the detent thingy? Is that the wiring thing with the ball and spring in it?

  • tool

Posted November 09, 2004 - 11:42 PM

#14

What about the external shifting mechanism? Is there something that can go wrong in it? Somebody said the detent thingy? Is that the wiring thing with the ball and spring in it?


ive never gotten a straight answer on if you can damage the ext. shift mech. i assume you can, but not sure how you could tell. i dont see how the "detent thingy" could fail, if it did i would think it would screw up the action of all the gears.
then again, i dont know.
whenever im rebuilding my trans (which is becoming far too frequent), i do the shift check after i put the cases together, but im still just hoping everything will work fine when i start it. so far, that has worked fine for me, so i dont know what to tell you. just ride it, it isnt worth another rebuild. your 5th gear has disappeared. :cry:

  • blue_beast_wins

Posted November 09, 2004 - 11:45 PM

#15

Did you swap the shim from the inside of fifth pinion to the outside ?

  • Satch0922

Posted November 10, 2004 - 06:25 AM

#16

Found this earlier and several people have confirmed that this fixed their bikes:


Here is your problem.
This was my 3rd gear. as you can see the the wheel has round edges and that causes it to try to push the fork away. That´s why it feels like it is slipping, that is everytime you deliver throttle and power enough for the wheel so that it can´t hold its position. Just replace the shift fork and the two wheels that are supposed to be held together when 5th gear is engaged..
http://frip.dk/jespertheil/2.JPG
http://frip.dk/jespertheil/3.JPG

  • darmino

Posted November 10, 2004 - 04:56 PM

#17

How blind are you people? the dogs on that gear are worn out, it looks far from ok! On each dog you can see its chipped and tapers back, they should be stright like a block of metal or a better example is that both sides of the dog should look the same.If worn, one side will taper back because only one side has pressure on it,except for during engine braking which is very little pressure and will not wear the dog. Now this poor sap has to split his case again. I wish I had seen this post sooner.

  • yzf450jack

Posted November 10, 2004 - 06:29 PM

#18

It looks to my that the fork is bent there should not have a grind mark on it only on the tips of the fork touches the gear. The dogs are not all the way in gear so it started popping out of gear and chipping the corners off I would change the two gears and that fork and you will be good :cry:

  • blue_beast_wins

Posted November 10, 2004 - 10:39 PM

#19

How blind are you people? the dogs on that gear are worn out, it looks far from ok! On each dog you can see its chipped and tapers back, they should be stright like a block of metal or a better example is that both sides of the dog should look the same.If worn, one side will taper back because only one side has pressure on it,except for during engine braking which is very little pressure and will not wear the dog. Now this poor sap has to split his case again. I wish I had seen this post sooner.


How blind are you when you missed this statement ! and i Quote,

"All that work and it's still skipping in 5th. The drum was fine, I replaced the gears and shift forks, everything was tight and clean and it's still skipping. I wanna burn the stupid thing. I don't know what to do now? Someone help me."

  • thumpinscott

Posted November 11, 2004 - 12:06 PM

#20

That and I'm somehow a sap. I am going to strip it down again and replace all the freaking gears. At least I am good at it now, I have practice tearing it down and rebuilding it.





Related Content

Forums
Photo

Is it worth it? (Cam and High compression piston) by macgi77


Dirt Bike   Make / Model Specific   Honda   CRF 150/230 F/L
  • Hot  36 replies
Forums
Photo

Michigan Motocross Tires by 288yz450


Dirt Bike   Dirt Bike Regional Discussion   North
  • 1 reply
Wiki
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info


Articles
  • 0 replies
Forums
Photo

2016 YZ450 by CaptainKnobby


Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies
Forums
Photo

James Stewart back on a YZ450F by YamaLink


Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 replies
 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.