01 tranny problems



21 replies to this topic
  • G-Man

Posted January 23, 2002 - 07:28 PM

#1

Well the saga continues....

Last week on the final lap it was stuck in 4th gear, thought it might have been mud or a rock.

Tested around the house and it shifted fine so I raced Sunday. Two practice sessions and two motos shifted fine. 3rd moto I heard a loud clunk from the tranny a few times but finished the moto with it shifting ok.

Started it up in the pits and the engine sounded funny internally. With the engine off you could hear metal to metal, when I kicked the kickstarter. (Top of the clutch seemed to be rubbing the case.)

Took it apart and found:

"My Clutch hub ring gear chipped a tooth, so I ordered an OEM (could not afford buying the Hinson AND the OEM as that is what you have to do, I found out!!). I also ordered the primary gear it connects to.

What I don't understand is why this clutch ring gear chipped, I flushed everything out the best I could....."

That was yesterday.

Well upon more flushing (laid bike on side and poured clean solvent on the exposed side case). More metal (steel) attached to my magnetic drain plug (I recommend these to EVERYONE!) Comparing the chips of metal to the chipped tooth, I have come to the conclusion that I have internal trans problems!!! I am really bummed about this and this is my 1st Yamaha after yrs of success on Honda's. As much as I love this bike, it could be the last one.

I have never worked on a 4-stroke motor let alone the trans, is it as frightening to do as it looks like? What might I find any tips or suggestions would be appreciated.

Thx,

G

  • fastkevin

Posted January 24, 2002 - 05:56 AM

#2

Why do you assume since you broke your trans. that ALL '01 426s have the same problem and/or it's Yamaha's fault? Don't mean to be antagonistic but you obviously race it.. How may times?? What's your shifting habits? ever blown any?? Are you the original owner? I have an'01 and never even have had so much as a hiccup, and same with the 400 I had before that. Racing puts added stress on a motor and trans.. don't you agree?

  • YZ400Court

Posted January 24, 2002 - 06:36 AM

#3

G-Man,
after you get past the cams and valves, the motor is just like a 2 smoke. There is nothing too scary in there. I had my 400 down to the last bolt, and have just begun reassemblly. I found some pretty good wear on the dogs on the sides of 1st, 2nd and 3rd gear. I also found a bent shift fork. Trans gears breaking seem pretty common in the rockier fast areas of the country. When your tapped in 3rd across a rocky strait at canyon, and go over some stuff that unloads the suspension, just to come down on some very unforgiving (not nice soft dirt) rock area, it causes huge stress on the gears. The tire goes from spinning like mad to hooking up like mad and bang goes a gear. It doesn't seem inherint to the '01 426, it seems inherent to the entire yzf4 family. As for racing the bike...I hope so. It is billed as a closed course race bike. I'm thinkin if I wanted a trail bike i'd have bought a XR-400, but I wanted a RACE bike that could handle the rigors of racing.

[ January 24, 2002: Message edited by: YZ400Court ]

  • fastkevin

Posted January 24, 2002 - 09:56 AM

#4

Yz400Court;
You are correct it is a racebike. A racebike requires more maintenance than a trailbike. Just like a Porsche requires more maintenance than a Toyota. And if you race either, they'll brake parts faster. I'll agree with you about the XR; If you want to just put gas in and go.. that's your bike.

  • Toomanybikes

Posted January 24, 2002 - 10:17 PM

#5

I don't mean to be contriversial or piss any one off. But, tranny problems are what has kept me away from the YZs in recent years. I am sorry to hear that Yamaha has still not fixed their continual tranny problems.

My opinion, but I think XRs are even worse. I have hands down changed more tranny gears in Radial Valve XRs than any other bike. Honda knows this and went to a under driven heavy duty four speed when racing thier XRs. Yamaha does the same in their racing fours.

  • Ga426owner

Posted January 24, 2002 - 10:55 PM

#6

I have had 5 YZF/WR's from 1999-2001. I have never had any tranny problems on any of them. I race my YZF at least 1 or 2 times per month. I usually, but not always, shift gears WITHOUT using the clutch, except on starts. So to state that YZF's are problematic to trannys is just not the case. Now I have probably just jinxed myself.........

  • YZ400Court

Posted January 24, 2002 - 02:51 PM

#7

Originally posted by Ga426owner:
I have had 5 YZF/WR's from 1999-2001. I have never had any tranny problems on any of them. I race my YZF at least 1 or 2 times per month. I usually, but not always, shift gears WITHOUT using the clutch, except on starts. So to state that YZF's are problematic to trannys is just not the case. Now I have probably just jinxed myself.........


Your racing in GA dirt, not Arizona granite, it makes a big diff. YZ's may hold up for 90% of the tracks and riding areas out there, for that matter 90% of them here in the desert may live long and happy lives. I do not know anyone who is a FAST desert racer on a YZF here in AZ that has not had a problem at one time or another. Lots of slow guys here have been afflicted here also. It only takes one time to go from sand to granite while the tire is spinning to bust things up. Also, 5 biles in 3 years, thats only 7 months a bike, raced 2 times per month, 14 races per bike. Ok, this is where I'm supposed to say I'm not trying to start anything, but hay, we are all entitled to our opinions. My opinion stinks just like all others, but I think the YZF is inadequate for hard long racing here in the land of granite.

[ January 24, 2002: Message edited by: YZ400Court ]

  • BK14MX

Posted January 24, 2002 - 03:19 PM

#8

I'll toss another theory in here, spent a year riding an 00' 426 in Georgia dirt, and believe me, theres alot of granite and assorted HARD dirt, without a single problem, I return to Florida, my home, ride twice in the sand and 2nd and 3rd gear dogs gave out. I know people from both sides of the spectrum of ability, some have had massive tranny failure, others like Ga426, who I do know personally, havent had a lick of trouble. I had a 97 yz250 that cost me 500 bucks in tranny parts, but again its entire life was spent in the soft sand of Florida. My 00'426 didnt have that big of a failure, just rounded the dogs off. Labor was the expensive part. Its tough to say whats easier or harder on any given transmission, but its a rough life being a dirt bike, and things are gonna fail. just my 2 cents.


Ga426, give me a shout, I should be back up there for a week next month.

  • fastkevin

Posted January 24, 2002 - 03:30 PM

#9

I spun my motor to the moon and then dumped the clutch.. The trans broke and it's Yamaha's fault :) What you're describing (Yz400court) is no different.

BK14mx: rounded dogs are just wear, plain and simple. You can damage(chip, chunk) them by various shifting techniques( for lack of a better word), but simple rounding is wear.
Look, I'm not the local Yamaha rep defending my employer. As a matter of fact, I just bought a 450 (that would be Honda). I just feel that having a 400 and then a 426, plus having several friends with the same, I'd know if there were a major design flaw with these bikes... I've seen nothing. I've never even seen a 400/426 with starting problems, that wasn't a result of operator malfunction. I have kicked over a 250f for a guy that was calling it every name in the book BECAUSE HE WAS HOLDING THE THROTTLE WIDE OPEN WITH THE CHOKE ON. I've also seen a guy bitch his bike(400) out, only to pull his air filter to see it so f-ed up it was disintegrating. Who's fault is that??
Take care of your bike and just ride the damn thing. If you abuse it, take responsibility for your actions.

[ January 24, 2002: Message edited by: fastkevin ]

  • BK14MX

Posted January 24, 2002 - 05:33 PM

#10

Fastkevin,
I agree with you on the wear thing, and I have since been very aware of my shifting habits. Also, these bikes make alot of power, period, and power can wear things out. Im not pissed at yamaha, well, actually i am cause I cracked Two OEM gas tanks, buts thats another thread altogether. I havent heard of too many trannies grenading, but rounding the dogs seem to be popular. In a perfect world, where all shifts are made correctly they would last forever, its the price we pay to play. Power is tough on everything.

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  • YZ400Court

Posted January 24, 2002 - 06:05 PM

#11

I still think the transmission should be able to handle the power of the engine. Does Destry break transmissions on his KX-500...no. Why? Because it is designed to handle the power the engine is capable of delivering. Does Johnny Break transmissions on his XR-650...no. Why? because it is designed to handle the power the engine is capable of delivering. Does Ty break transmissions in his YZ-426...yep, on a regular basis. Why?

  • CAL

Posted January 24, 2002 - 06:06 PM

#12

Originally posted by fastkevin:
Yz400Court;
A racebike requires more maintenance than a trailbike.


Yeah, well my DRZE (tralbike) just had $750 worth of trans. work done.

Is it as frightening as it looks? Well, here is my DRZ engine apart. LOTS of parts! Bike had less than 100 hours on it.

Shift dogs rounded, then the shift fork bent, then the dogs broke. After the dogs broke, they bounced around wiping out 2nd thru 4th gears...both driving and driven. Cost me $500 in parts and $250 in labor. The tranny broke in Nov., I just got the bike back last week.

Posted Image

[ January 24, 2002: Message edited by: CAL ]

  • YZ400Court

Posted January 24, 2002 - 06:23 PM

#13

Cal,
MY YZ 400 engine looks just like that right now. It really sucks. So which was it with you, poor maintenance or were you shifting wrong? Maybe you shouldn't have revved it too the moon and dumped the clutch :) . Just kidding :D . All that bitchin I've done about trans failures, and I have never had a failure either. Rounding dogs = normal wear, ok i'll accept that. My bent shift fork, no doubt caused by crashing hard in the rocks. I'm going to put WR 1st 2nd and 3rd in my bike to make it more manegable in the single track. I'm sure it will be fine for a long time. I guess your all right, S**t happens, and these are high stress motors.

  • YZ400Court

Posted January 24, 2002 - 08:39 PM

#14

Fastkevin,
Thanks for a good clean thread. The stuff over on the CRF forum is just plain drunken obserdity (not on your part obviosly). Keep it up you (what he said) :D . :D :) :D

  • Toomanybikes

Posted January 24, 2002 - 08:53 PM

#15

If shift dogs are just caused by wear, I will take Honda dogs over Yamaha. In my collection of bikes I still have a '93 CR 250, the cases have never been split. The bike has so many miles on it my boot has worn through the frame! :)
Thats right 3 frame guards and a frame worn out but no shift dogs.

I have replaced Yamaha gears after 2 months out of the crate.

[ January 24, 2002: Message edited by: Toomanybikes ]

  • CAL

Posted January 25, 2002 - 03:29 AM

#16

According to the mechanic, it was a freak failure of metal. I've always ran Mobil 1 15w50 plus X1R and changed it every 20 hours. I also NEVER shift with the clutch, but the mech. said that doesn't play a very big part in trans failure. He also said it's VERY hard to damage a tranny just from poor/low oil. He said he's seen trannys that have ran on NO oil for hours and be fine.

How would a crash bend your shift fork?

[ January 25, 2002: Message edited by: CAL ]

  • fastkevin

Posted January 25, 2002 - 05:51 AM

#17

Thanks there YZ400Court,
The nut over there was entertaining wasn't he? At one point, I came way too close to coughing milk up through my nose- THAT'S SERIOUS COMEDY.
This is actually an intelligent thread, with people simply expressing a difference of opinion (which is exactly what you said earlier) :)

  • CAL

Posted January 25, 2002 - 06:59 AM

#18

Originally posted by Ga426owner:
I have had 5 YZF/WR's from 1999-2001. I have never had any tranny problems on any of them. Now I have probably just jinxed myself.........


That's the way it goes with me. 15 minutes before my tranny blew, we were at the truck talking about how my DRZ was a tank. I was going on how I hadn't done anything except change the oil, put gas in it and ride....Then BOOM. Wasn't riding hard, wasn't even shifting when it failed. We ride a B class harescramble pace. So it's not like the bike has been through hard competition. Freak things will happen and it ALWAYS costs money. I just hope that when I get a 426, that the tranny doesn't blow in it. I'm still broke from paying for my DRZ tranny.

  • YZ400Court

Posted January 25, 2002 - 07:43 AM

#19

Originally posted by CAL:

How would a crash bend your shift fork?


My theory was if the bike is sliding on it's side across the desert floor, maybe the shiftr got hit so hard that the gear dogs hit face to facr rather than engaging, and with such force on the shifter the fork could have bent. I never bent the shift lever though, and really only crashed hard one time. I don't ride hard usually, just sit and lug most of the time. It may be a reach, but I don't know how else it may have been. I guess it could have been a manufacturing problem, but tyhe guy I bought it from never complained about it. The bike was rebuilt about 2 months before I bought it, by a good mechanic and the old forks were used. If it was bent at that time I think he would have seen it. It was pretty obvious the gear teeth had been grinding into the side of it.

[ January 25, 2002: Message edited by: YZ400Court ]

  • Sickman80

Posted January 25, 2002 - 10:19 PM

#20

Hey everyone, I'm new here. I race Pro-am in the ATV MX Nationals on my custom YZ426F powered 400EX. I can also run a 330R quad engine in the same frame and I work on both engines myself. I've torn my YZF engine down and the gears are more beefy than my quad engines gears are. Plus I've ran a '98 YZ400F converted to a 426 for a couple of years without any problem (Knock on wood) and an ATV puts much more stress on the gears than a bike. Plus I've never heard of any quad racers running the YZF experience tranny failures. But one thing to keep in mind is the YZ400/426F, as is the CRF450, is a light weight, compact, built for racing engine. So it is and will be a high maintenance engine (It's not 500lb XR or something). I tear my engine down once a year and inspect everything. While there I go ahead and replace the transmission bearings no matter what because if anything will cause failure, that's it (Just cheap insurance, and I've never had to replace a gear). Almost every YZF owner I've talked to say they've never touched the engine (A testimate to how strong the engine is). But the Manual even states for preventative maintenance replace the piston every six months. Most say, well it doesn't lack compression. That's not it, look how short the piston is and how fast it moves. The piston takes alot of abuse and if not maintained could possibly fail, as can any other part, including tranny parts. I'm not saying this is due to lack of maintenance, but sometimes parts fail, especially when raced. My dad used to make a living as a farmer and had to deal with equipment that too shouldn't break but would. All I know in general the YZF is a very reliable engine, but it does require attention if raced or ridden hard. If I ran a CRF 450 I'd do the same maintenance, because it is the same...

A sponsor of mine magnafluxed all of his gears to check for any cracks before re-assembling his engine once. Then the first time out he blew a gear in the tranny. There was no apparent damage to the gear, but for some unknown reason it failed and that unfortunatly sometimes happens.

Just my two-cents.

PS: I'm not bias in any way, I grew up on Honda's, I worked for Honda MFG on pre-production bikes, and Honda R&D is considering me for another internship this summer, and now I ride a Honda powered by a Yamaha...





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