[ViennaHog]

My left crank bearing (flat roller) went and destroyed pretty much everything inside the engine.
(http://v-twinforum.com/forums/showthread.php?t=64296)
Is it possible that :

• Running for about 100 miles with loose comp nut
  
• Drastically over-torqued comp nut (50% more)

could cause this type of failure?

Interested in your thoughts.

 

[motardue]

Ciao Vienna
for the firts evenience I have no idea. About the second I am not a qualified font but, seems me very difficoult overtightening, cause the ammount of strenght You must apply when tightening the damned thing to the new specs. I had to use a break bar of one mt, and it was still rearly hard to reeach the 45 degres more. Still wondering how I will be able to lousen it when the new brace I ordered from george pachecho will arrive.
How is Your's rebuilding going on?

 

[Ozzie In Arabia]

Hello Vienna Hog...........................based on what I have read on here and from some of the engine builders....Your bearing failure appears to be caused by the current problem with the 03, 04, 05 bikes ever since the moco changes the bearing design to what is currently installed.........


I dont believe the tightening of the sprocket nut would be putting any pressure on the left side bearing..........

All the best, Ozzie

 

[pa-glazier]

Maybe the luck of the draw and you got a one in a 10,000 or 100,000 bad bearing.:hmmm:

 

[Otto]

my Q is where the Flywheel true? and if so when installed was the pinion shaft runout excessive with could lead to the thought of the cases not being line burod correctly just food for thought

 

[ViennaHog]

my Q is where the Flywheel true? and if so when installed was the pinion shaft runout excessive with could lead to the thought of the cases not being line burod correctly just food for thought

Otto,
I have not checked the messed up crank assembly, but if we have time in the long winter months we could check. The cases were bone stock when it happened, so if anyhting was wrong there, it would have been the MoCos fault and for sure, they will admit it, wouldn't they?

thanks for the input

 

[johnny_red]

I've just ordered the parts required for the much talked about 3.37 gearing and have been reading the service manual to see what I can expect when doing the install. In the manual they talk about sprocket alignment, and placing shims behind the compensator to correct the alignment if required. I'm wondering if a set of misaligned sprockets could cause the crankshaft to shift and chew out the bearing.

 

[Otto]

the tech doing the build would need to know to check for it

 

[HIPPO]

Re#7, Yes, could be a cause or a strong contributing factor.

Loose nut, perhaps, indirectly, but I doubt it.
Overtorqued, no.

Crankshift?, possible, even likely.

 

[johnsachs]

Crank bearing took dump

Viennahog,
Absolutely the main cause of left side crank bearing failure is riding with a loose compensator sprocket ! The side to side movement of the flywheels beats the bearing cage to death.It may not fail instantly,butttttttttt,it will fail.
John
We have some high H.P.,and high mileage bikes ,that have the "dreaded bearing" with NO problems at all.

 

[HIPPO]

Howdy John, good to see you over here also.
Weather must be cold in FL too. LOL.

 

[johnsachs]

Hippo,
Thanks,Frank,these forums keep me on top of the market.That's how I learn in my old age.
John:wacko:

 

[ViennaHog]

Thanks for the insigths

Thanks guys for the insights. We will put together the engine with special attention to the comp nut and the alignment of the sprocket. I will use the traditional method for comp nut installation as it is a Timken conversion now.
Would that be correct?
Looks like the loose comp nut issue is somewhat underestimated when it comes to the risk of catastrophic engine failure. Next time the damn thing comes loose, I'll get a tow truck, it's a h$ell of lot cheaper than an engine rebuild........

 

[newultraclassic]

Thanks guys for the insights. We will put together the engine with special attention to the comp nut and the alignment of the sprocket. I will use the traditional method for comp nut installation as it is a Timken conversion now.
Would that be correct?
Looks like the loose comp nut issue is somewhat underestimated when it comes to the risk of catastrophic engine failure. Next time the damn thing comes loose, I'll get a tow truck, it's a h$ell of lot cheaper than an engine rebuild........

I would use the latest specification for tightening the compensation sprocket (initial torque plus additional degrees of turn per spec.) rather than the older method. The main issue is that it not come loose. If it's run loose, it can knock out any sort of bearing.

My 2 cents.

 

[Friday1]

Loose nuts

About 6 months ago we did a 124" S & S for a guy with an 04 Road King. I told him to bring it back when he got it ready to fire and I would do it for free, put a little dyno time on it and make sure nothing was leaking. We put gear drive cams in it too. Well, this guy was sort of impatient so we never saw him again til he had 450 miles on it and one hell of a noise hammering inside the motor. He removed the motor and was really pissed off, brought it back and I checked it out. I think he removed it to cover something he didn't want us to see, but that is just my gut speaking! LOL Anyhow I found that they had run it so long with the comnpensator loose that the splines on the alternator rotor were almost gone. Pieces of the spline were in the left side bearing and seal. The really strange thing was that the pinionn shaft gear that drives the gear drive cams had also come loose. I know I torqued it and it had red locktite in the threads. The "flat" on the pinion was no longer just flat but it was beat down on both ends of the flat. The noise was the cam gear slapping (the female hole in the gear was perfect-just the pinion itself was beat into a curve)back and forth. The nut holding the compensator together was all beat up I think they let the compensator come loose and then REALLY tightened it. Anyhow the crank needed a new pinion shaft, and rotor. Thinking about this now I wonder if it would help to put a locking compensator assembly on there. I know someone makes one but can't recall who. A loose compensator is a recipe for disaster! Friday