Spun Rod bearing, documentation of damage and rebuild

[tom.gabriele]

UPDATE: It was indeed a spun rod bearing, most likely due to low oil condition. see original post below, -documentation of damage, and fixing process further down.  i am no expert on the topic by any means, but feel free to consult my recently-acquired knowledge if i can be of any hellp to anyone else.


ORIGINAL POST:

I think my GS is in pretty rough shape right now. I was riding on Friday, made it about an hour from home, and after a nice run all the way through 1st-2nd-3rd it started making noise. Not pretty noise. I'm not sure which onomatopoeia to use, but maybe like a clanging growl. My first instinct was that it was just one of my PAIR system block off plates that came loose - sounded like an exhaust leak with clanging metal. That said, while it was a horrible sound, I wouldn't say it was a CATASTROPHIC sound. It was only minimally noticeable under 3-4k RPM, but got real angry anything over 5k. Unfortunately, I had to ride it like this for about a mile to the nearest business, which happened to be a little garage. I checked the oil, and it was barely on the dipstick, measured while trying to hold the bike vertical. I ended up adding 2.5 quarts. After I got it towed home and put the centerstand back on, it measured probably .5-1 quart overfilled. So I still had it embarrassingly low on oil. As you could probably guess, this did not help or change the noise. I did only run it for about 10 seconds after adding the oil - I had the gas tank off too, so it was just fuel left in the lines.

Bike did still run fine and idle successfully, but a little rough. Shifting seems to be unaffected.

From what I read here, the first low oil damage would be bearings. And the sound it was making seems to agree with that diagnosis too.

Now where would I go to start checking what broke? Will I just have to pull the motor, split it and take a look around, or what?  I'm hoping I can get some sort of diagnosis together before completely dismantling it.

Also - would it be sheer stupidity to run the bike at all before fixing it? I would want to use a stethoscope to try to determine the location of the sound and test the oil pressure, but if I am at eminent risk of causing even more damage, I obviously won't run it again. It would be nice if I were able to run it to help with the diagnosis though. 

[tom.gabriele]

What I  have checked so far (based on my limited knowledge):

- Under the valve cover:  vales and shims seem to be good, as well as cam retainers. This was the last thing I messed with - had to helicoil the valve cover bolts, so I had the intake valve cam retainers off. It is on tight, and the bike was running fine for a while, so i don't think that I put it on wrong or that it skipped a tooth. Cam chain seems to have proper tension all the way around.

- Exhaust system: pipes are tight to the head, PAIR block off plates are tight and sealed. Not other exhaust leaks/damage.

- The motor turns over fine. No extra resistance when turning engine by hand. No noticeable grinding noises when turning over slowly like this either. 

[adidasguy]

A few of us have had a counter balancer bearing go out. That makes a clanking sound as the bike runs.
Mine made a clanking sound for quite a while - not really that serious. Then one day the bearing finally went all the way out and WHAM! the loudest thrashing machine in the world. Engine still rann. Still shifted. just that awful noise.

Front right side is where it is:


how it looked with that washer removed:

[tom.gabriele]

I will start looking into the counterbalancer bearing.

I forgot to mention (I will edit OP right after this) - noticeable lack of power with noise. Marked after 4-5k RPM especially. Bike does still idle/run at lower RPM/shift ok though.

[tom.gabriele]

To anyone reading, this (http://gstwins.com/gsboard/index.php?topic=61017.0) thread has more info on counter balancer bearings and the replacement thereof.

Adidas - how would I go about checking that it is indeed the counter balancer bearing? Pull engine from frame and tear it apart? Can you direct me toward any particularly useful diagrams?

Appreciate the help, you are like a celebrity around here.

[adidasguy]

1. Run engine and listen to where the banging is coming from. A short 30 seconds should do no more damage.
2. If lower front, drain oil. Take off timing rotor. Take off right side cover (don't forget 2 bolts hidden under the timing rotor).
3. See if there is any movement on that bolt/washer in the first picture. I could clank it with my finger. It is not supposed to move.

With right side off, you can check everything else there for issues: clutch, etc.

When the oil is drained, it is not a bad idea to check the left side too. Might as well look at everything.

[tom.gabriele]

2. If lower front, drain oil. Take off timing rotor. Take off right side cover (don't forget 2 bolts hidden under the timing rotor).
3. See if there is any movement on that bolt/washer in the first picture. I could clank it with my finger. It is not supposed to move.

With right side off, you can check everything else there for issues: clutch, etc.

When the oil is drained, it is not a bad idea to check the left side too. Might as well look at everything.

Excellent timing, sir.  I got the notification of your reply just as I was standing over the bike, 8mm socket in  hand, thinking, "counter balancer is right side, right?"

Oil already drained - no significant metal pieces. Some metal powder making it a little shiny, but from what I understand, that is to be expected?

Will report back with right side findings.

[adidasguy]

I don't think shiny metal powder is a good thing. It means something is wearing out.
If not magnetic, it s the engine case (aluminum) somewhere. If magnetic, it is a steel bearing sleeve or something else steel.

[tom.gabriele]

Metal appears to be non magnetic. Lends credence to cb wearing on casing slightly. Fwiw, paper towel filter didn't even pick up particles they are so small



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[tom.gabriele]

Took off left + right side covers. Everything in there seems good - no free play in the counter balancer shaft except for the slightest bit laterally, i.e. it would move in and out looking at it from the side, or left to right looking at the bike head on. but only the slightest slightest bit.

I am past the end of my knowledge; I don't know what else to check.

[Funderb]

in your top pic, that bold with the giant fendery washery lookin' thing. take that off and you can inspect the CB shaft end.

[tom.gabriele]

Maybe a dumb question, but how do I stop it from turning the whole motor?


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[adidasguy]

First, check for any slop or movement. If none, then it is OK. On mine, it would move over 1/4" when I pressed sideways on the bolt head.

To remove something like that, have the engine in a high gear. Then with the wrench on it, give it a slap - like an impact wrench does. That will jerk the bolt free before the mass of the engine has a chance to start moving. But if it doesn't wiggle, then you're OK there.

another trick is to look at all the gears and see which direction things move. Stick a screw driver in the gears to stop them from moving (go ahead - rag on me for this one). But the gears are hardened steel. Something wedged in them should not cause any harm to get a small bolt off.

Any other ideas where the noise is coming from?

[sledge]

Stick a screw driver in the gears to stop them from moving (go ahead - rag on me for this one). But the gears are hardened steel. Something wedged in them should not cause any harm to get a small bolt off.

OK  ...I will take you up on the offer and say..........  use a small and much softer copper coin to jam the gears instead   

OP?....You can inspect whatever you want from the outside and talk about it for days but its pretty obvious you have suffered some serious internal damage. Forgive my pragmatic approach but unless you can get hold of some x-ray specs the only way to fully diagnose and attempt a repair is to get the engine out and split 

[tom.gabriele]

OK  ...I will take you up on the offer and say..........  use a small and much softer copper coin to jam the gears instead   

OP?....You can inspect whatever you want from the outside and talk about it for days but its pretty obvious you have suffered some serious internal damage. Forgive my pragmatic approach but unless you can get hold of some x-ray specs the only way to fully diagnose and attempt a repair is to get the engine out and split 
[/quote]

Ok, I just want to make sure I fully investigate everything I can before I pull and split the motor.  I figure once I get the motor apart that far, the chances I can't or don't get it back together increase exponentially.

My plans as of now are to remove and inspect the oil pan, then reassemble everything. After that, I'll take the chance, start it up, test the oil pressure, and try to pinpoint the source of the sound. That will help guide where I start looking.

After that, since the riding season is basically over now and I have all the time I need, I will take the time to finish cleaning out the garage and building the workbenches I want. Then I will have a good clean workspace upon which to start my first engine rebuild.

[tom.gabriele]

ok, bottom line; spun rod bearing. the most common first damage for a low-on-oil GS.

you will recall that I had some minuscule metal particles after draining oil. i pulled the oil pan:





or, if you would like to see that on a magnet:





aaaaaah!!! well if i wasn't sure i had a big problem before, I'M SURE NOW!!

I then proceeded to wrestle the motor out of the frame and split it. that was an interesting process in itself, but I will spare the details. suffice to say, it's easier if you take out all the bolts first.

this is what i encountered upon crank inspection:



notice the severe discoloration of the connecting rod journal to the right. telltale heat damage from a spun connecting rod bearing. the rod itself exhibited the same discoloring.

the rod bearing:



yes. definitely a problem.

i hopped on ebay and happened to find a crankshaft with connecting rods from a wrecked '06 for $75 shipped. others selling for $300+? i think i'll take it for $75. hopefully it is in good shape.

i will be stopping by my dealership after work tomorrow to get new bearings for everything, as well as gaskets for everything i removed. looks like i'll be in good shape. hopefully.


p.s. mod: feel free to move thread to projects, i will be updating with progress as i get it back together.

[weedahoe]

The bike I bought had a spun bearing too from low oil and looked the same except the PO threw a rod out the block. At least you can salage yours.

[tom.gabriele]

The bike I bought had a spun bearing too from low oil and looked the same except the PO threw a rod out the block. At least you can salage yours.

i don't know how to spell a whistle, but whew! that sucks.

...but i assume you bought it in full knowledge of the damage?

[weedahoe]

Yeah, I knew the engine was bad when I bought it and was already prepared to buy another engine.

[stokes776]

Nice pics Tom!  Let us know once you get it back together, and if it runs!

I currently have a '98 engine in my '04 bike because of potentially the same problem.

The 04 engine is sitting in my garage, I have separated the head from the bottom but have not cracked the crankcase yet.  I am interested to see how difficult it is to do this sort of repair.