Post Separation Anxiety...

[chaoselephant23]

Dang hydros! If it ain't one thing, its another! Way back at the end of April, I took my clutch replaced and CAM recalled 03 Stone Touring out at 7am to hit up the CT MGNOC Third Sunday Breakfast. Unfortunately I did not make it. Bike was running normally on all the back roads. Got on Route 9, got over the Old Saybrook bridge, bike went about 2 miles before I heard a weird jangle, that ca-scnitch! Bike started to slown down. Roll on the throttle provided no forward momentum. Got over to the side of the road safely. Tried to get it started using all the things that I currently know, but nothing worked. Got the bike towed home with help from the girlfriend. Started inspecting things. The RH plug looked fouled so I changed it out for a new one. Bike didn't start. Kept noticing a wah-wah-wah sound after the starter spun the flywheel. Opened up the inspection hole to find that the flywheel is spinning, but the crank shaft isn't Finally got the urge to crab for the clutch. Here is what I found:






Flywheel can be surface ground or skim cut. I'll be removing enough to warrant a new clutch pushrod or the 2 o-ring outer body on MGCycle. But my gut tells me that the crank shaft is toast. Anyone second that?

Which leads me to, anyone have a spare crankshaft for an 03 hydro, part number 37064106 OR a spare solid lifter 1100 engine?

[twhitaker]

What's in your gut that says the crank is toast? The screws will come out and that face can be recut to smooth it out. Since you've survived the crabbing, the rest should be downhill.

[Kiwi_Roy]

Bit of a touch-up and a new set of bolts
Perhaps the bolts were too loose and flogged off.

[fotoguzzi]

I have a 98 ev block with crank still in it, not too jazzed about shipped my it but if it's needed send me a pm

[chaoselephant23]

What's in your gut that says the crank is toast? The screws will come out and that face can be recut to smooth it out. Since you've survived the crabbing, the rest should be downhill.

My gut says that the gouge in the second pic at 2 o'clock is too deep for a re-cut. The gouge is close to even with the rear main seal. Worry that the flywheel, when mounted, will rub against the surface of the rear main seal and damage it slowly over time.

I also worry that a gouge of that size will throw the crank out of balance.

Then along with the amount being cut off the flywheel, as the gouge is as deep as the crankshaft, the clutch hub may not engage the clutch plate closest to the flywheel.

Will a recut need to go as deep as the gouge so that the gouge is gone? Or can I re-cut until the surface is true and keep whatever is left of the gouge without ill effect?

Bit of a touch-up and a new set of bolts
Perhaps the bolts were too loose and flogged off.

Believe my inexperience with bringing things to torque is what did me in. When I went in to replace the clutch, I took the flywheel off to clean all the clutch poo off the crankcase. Put back with Loctite 243 (well Permatex Blue), 10.9 bolts and Schnorr washers with convex side facing the bolt head. However I torqued, in a cross hatch pattern, 1/8 turn until snug, then 1/8 turn with torque wrench set to 30 ft/lbs until torque setting was met. I didn't do it in stages. For instance bring to 15 ft/lbs, then 20 ft/lbs, etc...

[Murray]

However I torqued, in a cross hatch pattern, 1/8 turn until snug, then 1/8 turn with torque wrench set to 30 ft/lbs until torque setting was met. I didn't do it in stages. For instance bring to 15 ft/lbs, then 20 ft/lbs, etc...

Umm what was the final setting, I won't claim to do Guzzi's but the flywheel bolts are just about the tightest bolts in any motor 120ft/lbs is normal.

[chaoselephant23]

Umm what was the final setting, I won't claim to do Guzzi's but the flywheel bolts are just about the tightest bolts in any motor 120ft/lbs is normal.

You might be onto something here, but in the opposite direction. I used the accepted value that you find everywhere on WildGuzzi.com, 30 ft/lbs. However the Service Manual from Guzzi has 25 - 30 Nm or 16 to 22 ft/lbs. So I was 8 ft/lbs too tight. This would certainly explain why the bolts sheared off.

Here is the torque table from the service manual:

[Wayne Orwig]

With good bolts, it is surprising that even a little too much torque did them in. And off of the top of my head I thought they were 30ft/lb anyway. I assume they were new.

Any chance that the flywheel or crank surface was oily so the flywheel was moving?

Me, being cheap, would clean things up with a wetstone and put it back. If it doesn't vibrate, you are good. Getting those hard loctited bolts out will be the challenge.

And get a new bolt/washer kit from MGcycle.

[Seamaster]

Those blots must be over 85ft/lbs, always check the TM

[Seamaster]

What size are those bolts? 10.9 mark is for high torque bolts that are almost the same as grade 8 bolts in US

[chaoselephant23]

With good bolts, it is surprising that even a little too much torque did them in. And off of the top of my head I thought they were 30ft/lb anyway. I assume they were new.

Any chance that the flywheel or crank surface was oily so the flywheel was moving?

Me, being cheap, would clean things up with a wetstone and put it back. If it doesn't vibrate, you are good. Getting those hard loctited bolts out will be the challenge.

And get a new bolt/washer kit from MGcycle.

Before assembly I cleaned up the surfaces with mineral spirit. Dried with compressed air. Then used scotchbrite to prep the surface. I did use a liberal amount of loctite placed directly into the crankshaft threads. Could seepage of loctite onto the mating surfaces during tightening be a culprit?

What size are those bolts? 10.9 mark is for high torque bolts that are almost the same as grade 8 bolts in US

M8 x 1.25 25mm

[tris]

The 10.9 designates the tensile strength of a metric bolt and should be stamped on the head of the bolt.
If it isn't marked (or has a number less than that), then unless its a special MG designed part, is aint high tensile (if it says 12.9 then that's OK - as even higher tensile strength)

A couple of other thoughts

If you put a shit load of Loctite down the holes then I guess you could effectively hydraulic the bolt. ie the thread lock in the bottom of the hole would prevent the bolt from pulling up properly even if the torque wrench clicked as expected

Is your torque wrench in calibration?

Did you tighten it up diagonally as good practice would suggest?

[brlawson]

http://www.cncexpo.com/MetricBoltTorque.aspx

M8 bolts of any spec will need to be torqued to inch pounds.

Also, if those bolt were over snugged previously they were compromised and should have been replaced.

Ran into this very issue when changing from a single to dual plate clutch.

[gerryp]

Chaos,

Where in Ct are you located?

Gerry

[chaoselephant23]

The 10.9 designates the tensile strength of a metric bolt and should be stamped on the head of the bolt.
If it isn't marked (or has a number less than that), then unless its a special MG designed part, is aint high tensile (if it says 12.9 then that's OK - as even higher tensile strength)

A couple of other thoughts

If you put a shit load of Loctite down the holes then I guess you could effectively hydraulic the bolt. ie the thread lock in the bottom of the hole would prevent the bolt from pulling up properly even if the torque wrench clicked as expected

Is your torque wrench in calibration?

Did you tighten it up diagonally as good practice would suggest?

Bolts have 10.9 stamped on their head. Got a kit from MGCycle that contained the bolts and schnorr washers. Here is a pic:


The torque wrench was brand new when I torqued the flywheel down. I however did not perform a calibration test. Adding this to the list of to dos.

Yes, I tightened in a cross hatch pattern. However I did not torque in stages.

http://www.cncexpo.com/MetricBoltTorque.aspx

M8 bolts of any spec will need to be torqued to inch pounds.

Also, if those bolt were over snugged previously they were compromised and should have been replaced.

Ran into this very issue when changing from a single to dual plate clutch.

Chart confirms the 22 ft/lbs found in the Guzzi Workshop manual.

Used a new flywheel bolt kit from MGCycle. Hopefully they weren't used

I knew something was bound to go wrong on my first attempt at motorcycle mechanics. A relief knowing that the consequences of this noob mistake can be remedied.

Chaos,

Where in Ct are you located?

Gerry

I'm located on the Southeastern Shores in Waterford. I'm originally from New London!

[tris]

Don't beat yourself up CE Not many people take on a clutch as one of their 1st jobs  and the way you describe things suggests you're not a Muppet   

That being said something wasn't quite right

So RTFM and double check everything and lm sure you'll get it sorted

[Tom H]

Here is a chart I found helpful:
https://www.swtc.edu/Ag_Power/diesel_engines/lecture/Metric%20torque%20values.pdf

Tom

[rodekyll]

ok
everybody take a breath on account of 22lb/ft and 30lb/ft are both correct answers.  Both torque values are listed in guzzi torque tables.

Now for what the heck.

Both are correct.  Only one is right.

Here's 30# torque





10.9 grade bolts.  six heads popped. six shafts sheared.  all six removed in three pieces each.  I'd post the other pics but they are identical to the OP's.

I am lucky -- I drilled mine out in situ without nicking threads.  I dressed up the mating surfaces and have just re-centered the torque converter.  If retorquing to 29 is a mistake, I'd best know it right now on account of I'm at MMnorth's house in Vancouver WA with a crapload of reassembly to do.

So . . ..  do I have to redisassebleize and retorque?  I've taken my brand new 8x1.25 10.9's to 29lb/ft.  I have always done this.  This is the first failure of never-used flywheel bolts, ever.

[mrrick]

Is there maybe a "unit of measure" problem here?
30 lb-ft is more than 40 Nm.
Table says 25-30 Nm for these bolts. In the middle of those values is 27.5 Nm = 20.3 lb-ft
Here's a conversion page: https://www.google.com/#q=tightening+toque+metric+to+foot+pounds

[John A]

Another possibility is " counterfeit bolts" that are not true 10.9

[rodekyll]

damn I wish some more mechanics would weigh in.  I'm late getting this borrowed dial indicator back.

[chaoselephant23]

ok
everybody take a breath on account of 22lb/ft and 30lb/ft are both correct answers.  Both torque values are listed in guzzi torque tables.

Now for what the heck.

Both are correct.  Only one is right.

Here's 30# torque

10.9 grade bolts.  six heads popped. six shafts sheared.  all six removed in three pieces each.  I'd post the other pics but they are identical to the OP's.

I am lucky -- I drilled mine out in situ without nicking threads.  I dressed up the mating surfaces and have just re-centered the torque converter.  If retorquing to 29 is a mistake, I'd best know it right now on account of I'm at MMnorth's house in Vancouver WA with a crapload of reassembly to do.

So . . ..  do I have to redisassebleize and retorque?  I've taken my brand new 8x1.25 10.9's to 29lb/ft.  I have always done this.  This is the first failure of never-used flywheel bolts, ever.

I'm still torn myself. I believe that I am going to avoid Loctite and use 30 ft/lbs. If you didn't use Loctite, then consider the flywheel a go. Even if you did, you've reduced the percentage of overage by going with 29 versus 30. But I'm no expert.

Another possibility is " counterfeit bolts" that are not true 10.9

Man I hate trick fasteners!  This time around I am going to grab 10.9s from McMaster and Carr. Fastener quality is always top notch.

[rodekyll]

There is a blue 'medium' Loctite gel in a tube that is real controllable.  #24005.  there used to be a putty in a chap-stick-looking tube.  That was the best.

Jason at Moto International just confirmed 30#.  All 6-hole flywheels with 8mm bolts.  All the time.  Always. So we weren't brain farting.  I'm taking the dial indicator back.   

As for counterfeits -- mine certainly were the dull charcoal color of 10.9, even in the breaks.  The replacemts are marked 10.9 but are bright plated.   

My flywheel surface was scuffed -- crank surface seemed unmarred.  I dressed up the flywheel surface and have good confidence that it doesn't need professional surfacing.

Good luck with your repair.  I should be running again in a couple of hours. 

[Idontwantapickle]

damn I wish some more mechanics would weigh in.  I'm late getting this borrowed dial indicator back.

IIRC the flywheel bolts yield, or stretch. I always discard them and get new ones. They should go on clean and dry. The manual for later big blocks says 30 ft/lbs.

Hunter

[bigbikerrick]

Could it be bad mettallurgy, as  when the bolts were hardened ,it was not done properly? I have used flywheel bolts from MG cycle with good results, but if I remember correctly, they were a dull black in color, but that was on an eldorado. I am not sure if both bikes use the same bolts.
Rick.