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Jeffro426

HEEELP!!! 5th gear problem

20 posts in this topic

My 2001 YZ 426 is got a problem...finally! :devil: When im in 5th gear, probably running over 5-6 thousand RPM and i get on it really hard it feels like the clutch is slipping or something...it does it about once a second and a half and only for a fraction of a second and only on hard packed dirt. It feels like your lightly tapping the clutch about once a second or so...but it doesnt do it when the RPMS are low or in any other gear than 5th. When the soil is loose you dont notice it. I thought at first maybe my 5th gear was going out but you would think it would do it at a faster rate and not so slow as im sure those gears are spinning pretty fast. All the other gears are perfectly fine and it shifts great...just 5th. Any ideas??? :thumbsup:

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Why not do an oil change, if somethings coming apart in there dumping the oil will definitely make you aware of it.

Good luck

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Already did...nothing unusual came out and it had the typical metal deposits in the filter. :thumbsup:

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Already did...nothing unusual came out and it had the typical metal deposits in the filter. :thumbsup:

my bike does the EXACT same thing. nothing in my oil either, runs perfect in every other gear...kinda feels like the chain is skipping teeth on the sprocket. im using my bike on pavement, and its pretty violent bucking.

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It's your tranny, specifically your shift forks. It's not your clutch as I've learned that if it were it'd do it in any gear.

You have a transmission problem and will need to split the cases.

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a few things can cause this

1 is your foot is hitting the shifter, if its just in fifth and no other gear this is most likly not the issue

2: Bent Shift fork

3: Bent shif fork worn out 5th Gear

At best its time to split the case and measure up the specs.

Do you have a magnetic drain plug?

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Any idea what a new shift fork and new 5th gear would cost?? I can split the cases myself...done it a million times on other bikes so the labors free! :thumbsup:

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Don't forget guys. A real good way to check for ANY gearing issue is to simply put the bike up on the stand pull in the clutch and as you shift thru the gears rolling the rear wheel backwards you will very easily see the chain kick as the tranny meshes with the bad teeth on what ever gear is selected. I had 1 tooth removed from 4th, it was very UN-noticable, and no debris in the oil. Did this test and WOW 4th gear made a real bad sound and look when I rolled the rear wheel over. Remember to roll it backwards as you shift up, that way you are loading the proper face of the gear teeth to feel / see the problem.

It works...it's easy...trust me!!!

:thumbsup:

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well according to Yamaha of troy depending on what fork

Prt#

8 FORK, SHIFT 1 1 $42.19

9 FORK, SHIFT 2 1 $43.54

10 FORK, SHIFT 3 1 $43.54

15 GEAR, 5TH WHEEL (20 TEETH) 1 $42.70

Roughly $100

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Is their 3 shift forks, or are those for differnt models?? 100 bucks isnt bad...cheaper than i thought it would be!

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There are Three Shift Forks in your bike

Just for your Information

Here is a link to the 250 side with a guy and the same problem...

web page

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same here but I was leaning towards ignition CDI box maybe? everything else ohm'd out good! I did the shift while rotateing the wheel backwards and all well! No noticeable clunks or clanks. Stumped here! :thumbsup::devil:

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i have a magnetic drain plug and there isnt a spec of anythign metallic on it after one day of roadracing. i also filtered the oil as id rained it with a paint strainer, and nothing there....but its looking like i have a tranny problem. if anyone wants to send me thier motor, i can take them all apart, and fix them all at the same time.

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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 trottle and power enough for the wheel so that it can´t hold its possition. Just replace the shift fork and the two wheels that are supposed to be held together when 5th gear is engaged.. :thumbsup:

http://frip.dk/jespertheil/2.JPG

http://frip.dk/jespertheil/3.JPG

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I had the same problem with my 01 426, but it happened at virtually any rev when you attempted acceleration. This is what I found on disassembly. :thumbsup:

gearbox.jpg

It's acutually the dogs on 3rd gear that have broken, but they are used to drive 5th.

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anyone have the part # for the flywheel puller? anything else needed for disassembly, aside from normal tools?

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I had the same problem with my 01 426, but it happened at virtually any rev when you attempted acceleration. This is what I found on disassembly. :thumbsup:

gearbox.jpg

It's acutually the dogs on 3rd gear that have broken, but they are used to drive 5th.

Thats happened to mine twice..........you cant fix it, it just keeps happening.......

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Same here. Mine were WELL rounded too as well as a lost pair of teeth. Was your shift fork blued from the heavy side loading? I ended up replacing mine from servere loading and discoloration.

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Was your shift fork blued from the heavy side loading?

yep, sure was. having the shift fork running on a broken gear wouldnt help the situation either :thumbsup: The rest of the gear was sitting on the oil pickup when I split the cases

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Just thought I would put in 2 cents. My 01 426 did have 5th gear failure, twice. I replace all 3 shift forks the first time, two gears, two bearings, gaskets and all was about $350.00. The second time it was because I didn't replace the fifth gear combo (the first time) that is pictured in the reply posts you already have read. However, I new they needed replacing but I had a race to get to!!!! So A year later, split cases once again, about $250.00 new Forks (all 3 again, dealer sent wrong ones first two tries), new 5th gear. We are jammin'... then it dropped a valve on a test ride for a friend who wants to buy it. :devil::thumbsup: We shall keep trying. Good luck. :awww:

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