4th Gear+Slipping=? Clutch gone?


18 replies to this topic
  • CHEEZE13

Posted June 20, 2005 - 03:53 AM

#1

I am ready to do the clutch change, but yesterday at high speed when I went to wot in 4th gear i got this I don't know felt like slipping, I looked down and could see the chain sorta bouncing, of the slider, sorta like when you first disengage the clutch and all the slack moves to the bottom side and the tension is on top, so it appeared to me that the this was clutch slippage, engaging-slipping-reengaging, but the funny thing is that it really only showed up like I said earlier in 4th gear @ high speed going from nothing to wot. Anyone had this problem. Smells like clutch to me, but???

  • CHEEZE13

Posted June 20, 2005 - 04:32 AM

#2

Damnit now I am all undecided, should I do the 01 clutch fix or just buy a Barnett Clutch? Would its clutch kit fix the issues the same as the 01 fix? Damn i hate decisions like this!

  • grayracer513

Posted June 20, 2005 - 07:54 AM

#3

Simple clutch slip should not make the chain bounce. Low rpm operation of a thumper will, though. If it's clutch slip, it will get worse as you go to higher gears, so it should slip worse in 4th than in 3rd, and worse yet in 5th. Get it up on pavement in 5th and clutch it hard a couple of times. A healthy clutch will take hold immediately, a weak one won't.

Do the '01 fix no matter whether you use OEM plates or anyone else's.

  • CHEEZE13

Posted June 20, 2005 - 09:28 AM

#4

thanx the thing is the chain made that eradict movement b/c, well think about it, if the clutch is slippin, then engages it is the same as standing on flat ground in neutral and shifting into first you know, and seeing the top half of the chain tension up, you know tensioning up i.e. clutch is pullin clutch slips chain is not being driven i.e. slackens up monetary, boom clutch grabs, that what's i am describing, but you know sometimes you can screw up the diagnosis if you don't articulate the problem correctly. do you concur? if not weak clutch what could other culprits be?

  • grayracer513

Posted June 20, 2005 - 09:47 AM

#5

Clutches don't generally behave that way. It is somewhat seldom that a clutch will slip/grab, or chatter, under heavy loads when fully engaged. If you have a situation in which the drive train is holding the applied load, then releasing, then grabbing abruptly, it could be 4th gear starting to loose its hold because of wear and/or a bent fork. Under that circumstance, the bike will force itself out of gear and drop back in again, leading to a jerky feel under a load. If this only happens in one gear, it the trans, not the clutch.

  • CHEEZE13

Posted June 20, 2005 - 10:11 AM

#6

shit that is what has been looming in the back of my mind, I am gonna run her down the road again tonight and see, if it is detectable in all gears, but yesterday i felt it only in 4th. so if clutch isn't slipping and its 4th what's the damage? time cost etc fixable?

  • Pincushion

Posted June 20, 2005 - 10:37 AM

#7

The cost is not cheap and its definately time consuming unless you're a Yamaha factory mechanic. I split my cases of my 2000 cause my motor ingested something it shouldn't have..... it did some tooth damage to 4th gear (both of them) and I'm also replacing 2nd, 3rd and 5th cause the dogs are starting to round off where they engage on the next gear. Gears are approx. $30 each from an online retailer as are the shift forks. If you need new shafts and shift drum then you're talking some serious dough.

It'll cost me $300+ just to replace the forks and gears.

  • grayracer513

Posted June 20, 2005 - 11:46 AM

#8

When one gear exhibits this behavior, the least you will need is the freewheeling element of that gear, the 4th pinion (mainshaft) in this case, and the gear next to it, in this case the 3rd pinion (mainshaft), which locks it to the shaft by sliding up and engaging the locking dogs, along with the associated shift fork. The locking dogs will be worn at the edges and along the driving face. Other gears may show enough wear to warrant replacing them as well.

  • John_Lorenz

Posted June 20, 2005 - 02:10 PM

#9

I think you said you had the 2000

the 2000 was noted for having a weak 3rd gear shift fork, this controlled as well 4th, and would give you the impression that 4th gear is bad.
No matter the tranny needs to come apart, most likly you will need a 3rd gear shift fork along with a 3rd and 4th gear

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  • 02YZ426

Posted June 20, 2005 - 02:13 PM

#10

The exact problem happened to mine except it was only in fifth gear. It does sort of seem like a clutch problem at first, but then when you realize its only in that one gear then you definatly know its not the clutch. When I took my engine out and split the cases, I found that the shift fork was bent, 5th gear, and third I believe was worn out on the clutching. It wasnt that difficult to repair, just time consuming and teadious. Hopfully you get it all worked out soon, Good luck

  • CHEEZE13

Posted June 20, 2005 - 03:00 PM

#11

Thanx guys for all the great info TT rocks! :) :)

  • CHEEZE13

Posted June 20, 2005 - 06:34 PM

#12

thanx 02yz426 i am praying that tommorrow when i give her one final analysis that she slips in other gears, i really don't want to split the case, but I will if I have to. :)

  • John_Lorenz

Posted June 21, 2005 - 06:55 AM

#13

If your interested in a Rekluse I may be able to help out, Not sure yet, but we may be raffling one off for the Legal Defense fund for Clear Creek

  • CHEEZE13

Posted June 21, 2005 - 10:18 AM

#14

How will the rekluse help me if 4th is gone?

  • CHEEZE13

Posted June 21, 2005 - 10:54 AM

#15

If I yank the engine and split the case is there any other parts i need to replace piston rings, etc.?

  • Hick

Posted June 21, 2005 - 06:07 PM

#16

Don't forget gaskets. For the cases you need Yamabond (other types of gasket maker would I suppose suffice), other gaskets you may be able to reuse, but you can never reuse the head gasket (also the most expensive one) and I wouldn't reuse the base gasket either.



If you buy a gasket kit you can save some money.

I also don't like to reuse the tab washers (like on the clutch hub and main shaft), but opinions vary.

Replacing the rings is not a bad idea since the whole thing is going to be apart anyway. Depending on the hours on the motor you may consider a new cam chain also.





Since you have an '00, make sure you check the straight key on the main shaft that secures the balancer drive gear while you have it all apart.


Hope this helps.

  • CHEEZE13

Posted June 21, 2005 - 06:20 PM

#17

Since you have an '00, make sure you check the straight key on the main shaft that secures the balancer drive gear while you have it all apart.


Hope this helps.


Please explain this in more detail. thnx

  • Hick

Posted June 21, 2005 - 10:27 PM

#18

Please explain this in more detail. thnx


Okay.

Based on your comment about the '01 "clutch fix" I'm assuming you have an '00. If not ignore all of this:

You may consider doing a search on "straight key" or even just "key." This is a well documented glitch on the 2000 model (only).

On the crank, right side of the motor, there are two gears, both held on by a nut, which is locked w/ one of those lock-tab washers (where you bend the tab up against the nut to keep if from backing off).

The first gear just behind the nut is the main gear, it drives the big ring gear on the clutch, it is held on the shaft with splines. Just behind it is another gear that drives the counterbalancer, which is located just in front of the crank. This gear is not splined, it is smooth with a keyway, and in the crank is a notch for a straight key.


The problem is that this key often gets worn, creating play between the shaft, gear, and counterbalancer. Due to the oscillating load placed on this gear by the counterbalancer any existing play leads to more play. It could be that some bikes were delivered w/ a key made of too-soft material. It could be that this gear needed to be splined to begin with (which Yamaha did beginning w/ the '01 model year). But once you have any '00 model 426 apart you should inspect this straight key for wear.


Hope this helps.

  • CHEEZE13

Posted June 22, 2005 - 03:25 AM

#19

Okay.

Based on your comment about the '01 "clutch fix" I'm assuming you have an '00. If not ignore all of this:

You may consider doing a search on "straight key" or even just "key." This is a well documented glitch on the 2000 model (only).

On the crank, right side of the motor, there are two gears, both held on by a nut, which is locked w/ one of those lock-tab washers (where you bend the tab up against the nut to keep if from backing off).

The first gear just behind the nut is the main gear, it drives the big ring gear on the clutch, it is held on the shaft with splines. Just behind it is another gear that drives the counterbalancer, which is located just in front of the crank. This gear is not splined, it is smooth with a keyway, and in the crank is a notch for a straight key.


The problem is that this key often gets worn, creating play between the shaft, gear, and counterbalancer. Due to the oscillating load placed on this gear by the counterbalancer any existing play leads to more play. It could be that some bikes were delivered w/ a key made of too-soft material. It could be that this gear needed to be splined to begin with (which Yamaha did beginning w/ the '01 model year). But once you have any '00 model 426 apart you should inspect this straight key for wear.


Hope this helps.


Thanx I will definately look at that.





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