07 YZ450F Transmission Failure

[DesertRacer2]

I just got home early from my weekend riding trip because my 07 YZ450 broke down. I was riding down a dirt road in 4 th gear, doing about 45 mph when my bike suddenly popped out of gear and I heard a whining sound coming from the engine. When I gave it gas it just reved up and went no where. I turned the bike off and tried shifting it into neutral. I got it back in to first and decided I better get back to camp. I got about 20 feet and the bike locked up, engine died, and I slid for about 10 feet. At this point the bike would not shift up or down. It is stuck in gear. Even when I pull in the clutch, I cannot move the bike without dragging the rear tire. The weird thing is I can start the bike with the clutch in, and it runs fine, no whining sound, but when I let the clutch out it just dies. I have had a lot of bikes and I have never had a problem like this. I am frustrated because I have only had this for a little over a year and I always maintain my bikes and never abuse them. Any help on this matter would be greatly appreciated. I have no idea what is wrong or how much it is going to cost to get fixed. Thanks.

[wheeldude]

Sounds like fourth gear has broken and locked up the transmission by wedging between 2 other gears or the case and geartrain. You can start it with the clutch in because you are dissengaging the trans from the crank by pulling the clutch in. The fact that it will not roll, indicates the trans is locked up. Plan on the engine having to come apart. Sorry to be the bearer of bad news. WD

[DesertRacer2]

I am just looking for all the information I can get. Thanks for the help.

[nickeenoo]

I wonder if this has anything to do with the shifting issues some of the magazines have reported. I have an 07 and I have a hard time going from first to second. Also, I find a false neutral between 4th and 5th on a regular basis. The bike is fairly new so I was expecting things to smooth out as the bike broke in. Maybe not?

I'll be interested to hear what others have to say and also see what the problem actually is. If the 07's have tranny problems, maybe a preventative measure would be to replace some of the gears with 06 or 08 parts before there is a major failure?

Nate

[grayracer513]

Nope. Something broke, simple as that. Very unusual, too. The only way you're going to get any more info than that is through exploratory surgery.

[DesertRacer2]

I know, a lot of people I know have had great luck with their Yamaha's. I was shocked. Does any one have any idea how much a shop may charge if I remove the engine from the bike and take it down?

[grayracer513]

I'm sure they would quote it to you over the phone but my guess is somewhere between 5-8 hours at whatever their rate is.

Can't do it on your own?

[DesertRacer2]

Thanks for the info Gray. My mechanical ability was always limited to general maintenance and two stroke top ends. I never did a bottom end and the thought of doing one with the addition of taking a four stroke top end apart scares me. Although, after I get some quotes over the phone, depending on the cost, there may be a first time for everything.

[DesertRacer2]

I took my engine down to my dealer 2 weeks ago. They tore the engine down and discovered I had two gears break which locked up my transmission. All of my shift forks were bent and I need a new oil pump. I don't know all of the specifics yet, I should be picking up the engine this week some time. The mechanic said that since Yamaha came out with the YZ400 in 98, this is the third transmission he has done. He said it was a total fluke. So, since the motor was apart, I had them replace the piston and rings, and $1500 later, I should hopefully be riding this weekend after I get the sucker back in. Fun stuff ?

[WFOracer]

Dang, for $1,500 did they at least use lube?

[grayracer513]

That's why it pays to learn to deal with stuff like that for yourself, if you can.

[DesertRacer2]

I agree, however, I don't think this should have happened in the first place. I always maintain my bikes and for this to happen is extremely frustrating.

[grayracer513]

I agree, however, I don't think this should have happened in the first place.

It shouldn't have, based on history, and as your friend pointed out, it usually doesn't. But it was made by humans, after all. ?

[BBrown626]

I agree, however, I don't think this should have happened in the first place. I always maintain my bikes and for this to happen is extremely frustrating.

The very same thing happened to my '04 a couple months ago. I am doing the work myself, but it isn't going easy. I had to order more parts after i tried to put it back together I found the drive shaft was damaged too. Once I got that new part I found that the guide for one shift fork was dented and possibly displaced. The shifting fork binds, keeping it from shifting consistantly. The case needs to be replaced. OUCH!

It was my 3rd gear that was missing 2 teeth, 4th gear was split in half and a few other gears/pinions were damaged, along with shifting forks. I hope it is done soon.

[todds924]

I know, a lot of people I know have had great luck with their Yamaha's. I was shocked. Does any one have any idea how much a shop may charge if I remove the engine from the bike and take it down?

Engine removed should be no more than 300 dollars labor. its about 3.5 hours to do that job. If you get any quotes for more than that.....move on. Its a very easy job with the engine removed. I think you could do it yourself. Follow the sevice manual. If you have done 2 stroke top ends, ther should be no reason you couldn't do this. The cases on these come apart very easily. Most peoiple think gears and parts are going to come falling out when the case is split but it isnt true. Everything will stay in the RIGHT hand side of the case, you don't even need to remove the shift drum Mechanism. It all stays in the right hand side with the tranny.

[hillclimbguy]

Wow that seems high, Maybe if you took it to a car dealer it might of been cheaper.

Why is it that the smaller the item, the more expensive it is?

Muffler for my truck 200 bucks installed. Muffler for my 450, 350 bucks and my labor.

[rickallen124]

Wow that seems high, Maybe if you took it to a car dealer it might of been cheaper.

Why is it that the smaller the item, the more expensive it is?

Muffler for my truck 200 bucks installed. Muffler for my 450, 350 bucks and my labor.

It's an economy of scale, the more they make the cheaper it is to make it. I'm pretty sure the number of trucks out there is close to ten times, probably more, the amount of bikes out there. Smaller production equals higher costs per unit.

[Dveitch8]

I wonder if this has anything to do with the shifting issues some of the magazines have reported. I have an 07 and I have a hard time going from first to second. Also, I find a false neutral between 4th and 5th on a regular basis. The bike is fairly new so I was expecting things to smooth out as the bike broke in. Maybe not?

I'll be interested to hear what others have to say and also see what the problem actually is. If the 07's have tranny problems, maybe a preventative measure would be to replace some of the gears with 06 or 08 parts before there is a major failure?

Nate

I also have an 07 and sometimes going from 1st to 2nd is hard and it seems to get hung up in neutral. Anyone else having the same issue or looked into it?

[BBrown626]

Lots of folks reporting tranny issues on this site. Maybe the YZ's valve train is bullet-proof, but not the whole engine?

Are we shifting wrong?

Material defects?

About the right number of failures given the number of bikes in service?

Engine just too powerful for the tranny when used by us recreational riders that don't replace the tranny every couple of races?

Part of the economic stimulation plan?

[grayracer513]

Wow that seems high, Maybe if you took it to a car dealer it might of been cheaper.

Why is it that the smaller the item, the more expensive it is?

Muffler for my truck 200 bucks installed. Muffler for my 450, 350 bucks and my labor.

3.5 hours to completely disassemble and carefully, properly reassemble a YZ450 engine (leaving the head alone and reconditioning the transmission) is something only an expert with at least some familiarity with that specific model could accomplish, and the $85/hr that estimate represents is about what gets charged these days.

By contrast, a muffler swap on most cars takes less than an hour with replacement parts that fit and the right tools. Furthermore, the muffler itself is made by the thousands automatically, with very little human intervention, while the aftermarket mufflers for motorcycles are made in very small numbers, and have a considerable amount of hand work involved.