mlglemon

Transmission failure (disintegrated gears). Is anything in the bottom end salvageable?

7 posts in this topic

Posted (edited)

Quick engine specs - DRZ400E base engine w/440 CW kit, FCR39 & MRD pipe in an '06 SM.

 

I had just finished a head gasket replacement after putting dozens of hours on the bike after purchase with no issues other than the head gasket. The issue causing the head gasket was resolved (hopefully).

 

About an hour into riding, the transmission went boom but the engine was still running, shut it down right after. It was not ran again. A year later, I split the cases to find this (see pics). I know I should probably do the right thing and replace all bearings/main/crankshaft because of the metal debris I found, but in cases like these, is there any amount of inspection or cleaning that would validate the crankshaft, at the very least? A few of the bearings are very obvious replacements, but the mains look and feel okay, as does the crankshaft. I can have it inspected very strenuously by my QC department at work.

 

If not, I can source a Hot Rods crank & main bearings for around $250 and find the rest at a bearing house. I don't like to pay twice but I also don't want to be overly careful. Is it the previous damage caused by floating debris that requires bearing replacement or the possibility that debris remains and would cause future damage? Or....a little column A, little column B?

 

Thanks in advance for any guidance. I think I already know the answer... :'(

 

 

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Edited by mlglemon

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The concern I would have with the ball bearings would be possible roll-in damage or overloading from the debris. Bearings are relatively cheap. Because of the time and effort to replace them, I would assemble with new components if it was my engine .

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Guess it isn't too bad. Hard to stomach since I'd planned on selling soon but I'd rather do it right than leave the new owner with a time bomb.

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35 minutes ago, Kawidad said:

Holy smokes! What'd you do to that thing?

Probably nothing he did. Parts fail

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I think I would replace the crank main bearings and all the other ball bearings but reuse the crank.  The big end receives its oil via the oil pump and filter and not so likely to have picked up debris that was flung around.  It obviously did not run much after the failure.

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Thanks, Noble. I pored over the lubrication system chart while following the oil passageways and I can see where the clutch cover feeds the right end of the crankshaft. This does give me some peace of mind.

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