2006 AE: serious, repeated "THUNK" when getting underway

[PhilMills]

Since I have to take the bike in for the grounding recall anyway, I figure I might as well try and solve the last problem I've got with it at the same time.

Periodically, my 2006 AE will make a repeated "THUNK" feeling when starting from a dead stop. This isn't the usual "THUNK" of going Neutral to First, but more like repeated, fairly violent, drive-line lash takeup. It feels like someone's taking a mallet to the frame, or the bike is bucking.

Get off the brake > Open the throttle > start moving > WHUNK.WHUNK.WHUNK.WHUNK > up to speed and into 2nd.

Once I get it into 2nd, no more problem and I can put as much throttle as I want into it and not slip.

I can't seem to tie it to warm/cold or a certain kind of oil since it will do it for 3 stop lights in a row and then not again for a couple of weeks...

Anybody got a guess? Fluids are all good, no obvious crap in the engine or swingarm oil, fresh oil, filters, plugs and valve check at 15K a few months back, works perfectly 95% of the time...

 

[ScottyUSN]

But it feels like it's coming from the engine?

 

[RadioHowie]

Sounds like the 1st gear "dogs" might be trying to pop out under power.

Let's hope not! :dribble:

 

[PhilMills]

But it feels like it's coming from the engine?

Kind of. Hard to tell in traffic with a helmet on. My initial thought was "WTF? Have I broken a motor mount?", but that isn't it.

 

[PhilMills]

Sounds like the 1st gear "dogs" might be trying to pop out under power.

Let's hope not! :dribble:

Hm. That's mechanical, so I'd think to expect more repeatability out of it.

On the idea that it might be, though, how painful is it to do a transmission teardown on the FJR to diagnose it?

 

[PhilMills]

This thread from 2006 kind of sounds close. And I do believe my YES warranty expired earlier in the year. I'm probably going to be kicking myself for not having brought it in the first time it did it, aren't i.

 

[networkguy]

This has been talked about quite a bit.

HERE is one thread. My thread about this issue is HERE

 

[RadioHowie]

Sounds like the 1st gear "dogs" might be trying to pop out under power.

Let's hope not! :dribble:

Hm. That's mechanical, so I'd think to expect more repeatability out of it.

It would depend on how hard you were twisting the loud handle at the time of the shift. More power/torque applied, more chance of a slipping dog.

On the idea that it might be, though, how painful is it to do a transmission teardown on the FJR to diagnose it?

One word answer? VERY!

Motor HAS to come out, cases split to reveal the trans.

 

[PhilMills]

This has been talked about quite a bit.

HERE is one thread. My thread about this issue is HERE

Ya know, I *tried* to find something like those threads and could not find the magic set of search terms. I sure as hell like "overnight clutch soak" a LOT better than "$2000 in labor to open up the transmission".

And, of course, my YES warranty DID expire last month. The dealer here suggested I might call them and try to work something out, but I'll definitely try the soak first.

 

[PhilMills]

Sounds like the 1st gear "dogs" might be trying to pop out under power.

Let's hope not! :dribble:

Hm. That's mechanical, so I'd think to expect more repeatability out of it.

It would depend on how hard you were twisting the loud handle at the time of the shift. More power/torque applied, more chance of a slipping dog.

On the idea that it might be, though, how painful is it to do a transmission teardown on the FJR to diagnose it?

One word answer? VERY!

Motor HAS to come out, cases split to reveal the trans.

That's one of the things I've been wondering about with this - it doesn't matter if I'm babying it or playing for pinks with some twerps in Daddy's new Mustang; it does it regardless.

 

[BwanaDik]

Might be a u-joint going out? That's the exact sound that my wife's car made when the u-joint failed. And it happened from a standing start up to speed. And not every time either, seemed to depend on where the u-joint stopped when the car stopped.

 

[wfooshee]

I was thinking the u-joint at the front of the drive shaft, but I don't know why it would be first gear only. But worn u-joint bearing will make for some flopping about at the head of the Driveshaft, right at the outlet from the tranny.

I'm afraid of maybe bent first-gear shift fork, causing less-than-full engagement once in a while.

Hope not, because: $$$ ka-Ching $$$

 

[PhilMills]

Well, I gave it all a soak today for about 8 hours. Everything's nice and oily.

I put it all back together, torqued it all down, turned the key, and.... SH_26.

The forum suggests a clutch bleed for that code, but I don't recall seeing anyone reporting an error code after a clutch soak.

While I'm breaking out the Mit-y-vac, I put it to the collected wisdom of the forum: what'd I do wrong?

I had the bike in 1st so I could get the bolts on the clutch spring holder to hold still enough to break loose; all the parts seem to fit, nothing's left over except 2 bolts from the fairing I haven't put back on yet, I didn't leave the rag stuffed in the hole...

 

[PhilMills]

Well, I gave it all a soak today for about 8 hours. Everything's nice and oily.

I put it all back together, torqued it all down, turned the key, and.... SH_26.

The forum suggests a clutch bleed for that code, but I don't recall seeing anyone reporting an error code after a clutch soak.

While I'm breaking out the Mit-y-vac, I put it to the collected wisdom of the forum: what'd I do wrong?

I had the bike in 1st so I could get the bolts on the clutch spring holder to hold still enough to break loose; all the parts seem to fit, nothing's left over except 2 bolts from the fairing I haven't put back on yet, I didn't leave the rag stuffed in the hole...

Additional: in 1st gear on the center stand, the rear wheel rotates a bit and then catches, but continues to spin against some resistance.

The shift light/SH_26 code now only comes on when I pull in the brake lever after the key's turned on.

I saw in another SH_26 post that somebody'd found an "easier than pulling the swingarm" way to get to the manual actuation bolt for the clutch bleed, but he hasn't been on the forum since mid 2010. Anybody have an idea what that was?

 

[BwanaDik]

You're making me nervious, same bike as mine.

How many miles are on it?

Keep us posted.

Mcatrophy to the white courtesy telephone please!

 

[PhilMills]

You're making me nervious, same bike as mine.

How many miles are on it?

Keep us posted.

Mcatrophy to the white courtesy telephone please!

15000-ish. I just did the valve check and air filter (placement of which I want to discuss with some Yamaha engineer) a few months ago. I figure it's got to be something obvious - the clutch soak is common enough and simple enough that there's only so much I can have done wrong.

 

[Donal]

Sounds like you have experienced the same problem that Mcatrophy had when he finidhed his 'clutch soak'. have a look here Scroll down until you see "clutch Grabbing" then have a look at para 6. Hopefully that will put you on the right track

Don

 

[PhilMills]

Sounds like you have experienced the same problem that Mcatrophy had when he finidhed his 'clutch soak'. have a look here Scroll down until you see "clutch Grabbing" then have a look at para 6. Hopefully that will put you on the right track

Don

That was actually the photo walkthrough that I used - I found the photo slideshow, but not the page you linked up. I guess it's back in to pull it all apart, then.

Though: does anybody have a good picture of that manual actuator bolt's location? It would be nice to get it PROPERLY bled...

 

[Donal]

The best I can come up with (for now) is a parts microfiche Here

I guess someone needs to drag Mcatrophy out of the bar or wherever he's hiding! You can never find people when you need them!! :angry2:

Don