Front sprocket came loose

[Apothecary]

So on the highway last week, I suddenly lost power, but the engine was still running. Long story short, as I'm looking at it the other day, the nut that holds the front sprocket on was MIA and the sprocket still spinning while i was going, destroyed all the threads that the replacement nut needs to screw onto.

Looking at the transmission parts diagram here 2006 Yamaha FZ6 - FZS6V Parts, 2006 Yamaha FZ6 - FZS6V OEM Parts - BikeBandit.com it looks like I need to replace the drive axle (part number 1217257 on that site).

Has anybody had to do something like that before? What am I looking at to get the transmission apart and replace that?

 

[ChevyFazer]

That nut, if im not wrong is a recall item so maybe if your lucky yamaha might pick up the bill for any.repairs.

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[Apothecary]

Oh wow, that would be amazing. I've never dealt with anything like that before, should I just call up the service department of my local dealer?

 

[ChevyFazer]

Yea call a dealer and.find out if the recall has been done and.if not explain to.them what happend, i dont know if they will actually fix it or not since just the nut is recalled but it wouldnt hurt to try

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[Shamus McFeeley]

I don't see anything about a recall for the 2006 FZ on the nhtsa site:

Vehicle Owners | Safercar -- National Highway Traffic Safety Administration (NHTSA)

You'll be at the mercy of the dealer. Good luck.

 

[PhotoAl]

There was a recall at least for the 2004 FZ6. Bought my bike 2 and a half years ago, took it to the dealer and they did the recall on the nut, the throttle recall was taken care of by the previous owner.

 

[tejkowskit]

I thought the nut/washer thing that was recalled on the 04/05 models was resolved by the time the 06 bikes were out. Could be wrong though. Let us know when you find out! I too have an 06.

 

[turbid]

the 06 have a flat washer on the nut to stop it from coming loose. maybe the previous owner changed the chain/sprocket and did not put the washer back? it does not harm to ask a dealer but i dont figure they would be willing to replace it for free. can t the drive shaft be rethreaded, car mechanics usually do this a when they strip the threads on spark plugs

 

[TownsendsFJR1300]

the 06 have a flat washer on the nut to stop it from coming loose. maybe the previous owner changed the chain/sprocket and did not put the washer back? it does not harm to ask a dealer but i dont figure they would be willing to replace it for free. can t the drive shaft be rethreaded, car mechanics usually do this a when they strip the threads on spark plugs

Re-threading a hardened steel shaft is completly different and MUCH MORE difficult than putting a Heli coil, or Time insert into a head.

If the shaft threads aren't too messed up, he may be able to get a metric thread file and gently go over the shaft with the file and clean the threads back up. If not, the OP has a big job ahead of him.

Should the damage be a result of a re-call, Yamaha would likely pick up the entire fix. I don't believe the 06 was in that re-call..

On my 04 FJR, some of the bikes (03-05) were having problems with the exhaust valve guides failing("the dreaded tick"). The bike is currently way out of warranty however on the FJR forum, its said that Yamaha will still fix the bike (free) as it was a known problem... Mine doesn't tick so I can't verify that personally...

 

[ChevyFazer]

I cant see sigs or what not.so.i.didnt know what year his.bike was but still wouldnt hurt to call the dealer and ask...and +1 on what fjr said there is almost no way to rethread a hardened shaft unless you temper it back to a soft state, then try to rethread, then reharden. But if someone put that much work into it they could have saves them selves alot of time and money by just buying a new one

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[turbid]

ah i'm sorry i thought it could be a cheap fix

 

[TownsendsFJR1300]

ah i'm sorry i thought it could be a cheap fix

Actually it could be a cheap fix...

Get a steel sprocket (no rubber cushion) and MIG weld it on the shaft. The splines will keep it from spinning on the shaft, the weld will keep it taught to the shaft...

Its not the factory way to fix it but it'd work...

 

[FinalImpact]

Can you clean it up and get a good Macro Zoom picture???

How bad is it? If the threads are rolled over it may be salvageable....

Two concerns about the last ditch effort of welding it; heat killing the seal behind it. And making the shaft brittle. However, I think the shaft is only induction hardened on the outside so if you keep the temp down, this could get you a good distance down the road!

 

[Cali rider]

You could try to chase the threads with a metric thread file and purchase a new sprocket, nut and washer. If the fit between the splines of the sprocket and shaft are still tight AND you can get full rated torque on the nut then you can get away with using the old shaft. If any of this is loose you will have to replace the shaft. The cost of the actual output shaft is about $90, but the labor will kill you if you are not up to doing the repair yourself. At that point, it might be more economical to buy a used motor.

MIG welding is an option, I guess. Not my style of repair work. In 20-30K miles, when you need to replace the sprocket and chain, this repair will complicate things. Speculation runs amok...

Sorry to hear about this, but you are lucky it didn't lock the wheel up at highway speed.

 

[ChevyFazer]

Can you clean it up and get a good Macro Zoom picture???

How bad is it? If the threads are rolled over it may be salvageable....

Two concerns about the last ditch effort of welding it; heat killing the seal behind it. And making the shaft brittle. However, I think the shaft is only induction hardened on the outside so if you keep the temp down, this could get you a good distance down the road!

Welding it wouldn't make it brittle at all, it would however take some of the hardness out of the shaft (softer) but the point of hardening them is to make the teeth/threds stronger, the only part that matters, but if this route was taken i would be more worrid about getting the sprocket aligned perfect, any little bit off and it would be chewing up chains or throwing chains like no ones business

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[TownsendsFJR1300]

I mentioned a metric thread file earlier in the thread would be the way to go if the shafts not too torn up..

If the OP can afford the $ to fix it correctly, obviously that's the way to go but your talking an engine removal and tear down. Hopefully the mechanic doing the work is experianced and doesn't screw up something else (been there and experianced that with my old Goldwing).

Swapping out the welded sprocket would just take a cut off wheel cutting at the old sprocket /weld trying to avoid the main shaft until its loose.

As stated earlier this isn't the correct way to fix it however, I would do this before buying a new engine. Getting it flush would just require a couple of tack welds. The shaft is pretty meaty as is the sprocket.

And yes, you'd have to try and keep that oil seal as cool as possible, that would be the hardest part......


Looking at the Yamaha manual, it appears you can get by with pulling the engine, leaving the top end on and just removing the lower crankcase. You'd have access to that damaged shaft and would be able to pull it without much other dissassembly (page 5-56).. Its not connected to anything on the right side and doesn't even come thru that right main case.

I do remember seeing on this forum, someone doing an engine tear down with pic's for a knocking rod. A search and then contact with him may confirm this...

BTW, I have an 07 Yamaha manual as a PDF file if you need it... PM me..

 

[Apothecary]

Just got off the phone with the dealer, there were no recalls on that nut for the 2006 model year.

The welding idea might be a good option as a temporary fix. Worst case scenario, it hurts a shaft that's already broken. In Texas, it's so hot most of the year that I was really bummed about my bike being down during the beautiful fall riding season.

I'll try to get a close up pic of what's left of the threads for you guys after work today.

Thanks so much for the help.

 

[TownsendsFJR1300]

Just got off the phone with the dealer, there were no recalls on that nut for the 2006 model year.

The welding idea might be a good option as a temporary fix. Worst case scenario, it hurts a shaft that's already broken. In Texas, it's so hot most of the year that I was really bummed about my bike being down during the beautiful fall riding season.

I'll try to get a close up pic of what's left of the threads for you guys after work today.

Thanks so much for the help.

PM sent...

 

[FinalImpact]

Some R6 Guts. . .
Output shaft with sprocket
https://picasaweb.google.com/114258...id=hyVo9q4X3R4yNvVBRFS7yA#5174567829622044146

Input, Output, shift rails, out of case. . .
https://picasaweb.google.com/114258...id=hyVo9q4X3R4yNvVBRFS7yA#5174567481729693026

Input cluster, not the issue but something to look at.
https://picasaweb.google.com/114258...id=hyVo9q4X3R4yNvVBRFS7yA#5174567249801459010

Input cluster and shift drum in the Top Case:
https://picasaweb.google.com/114258...id=hyVo9q4X3R4yNvVBRFS7yA#5174567709362959810

From:
http://www.600riders.com/forum/gara...ke-guts-heres-bunch-r6-engine-trans-pics.html

I can't imagine doing an in frame overhaul. . . . not my thing.

The good news is the crank and all the oiling and timing chains can likely stay in place so a bulk of the work is getting it out of bike. After that its nuts bolts and snap ring pliers. Assuming you have a clean place to do such work??

Lets see what you have to work with and if the threads can be cleaned up?!! Maybe between a metric thread file and thread chaser die (worth the expense!), you can clean it up? As said, it only needs a few good threads (likely half the width of the nut) to reach torque spec and with Loctite, you'd be good to go!

 

[TownsendsFJR1300]

I just sent him a shop manual....

Also, should you go the welding route, disconnect the battery and the ECU so you don't fry anything....