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Is this common? Blew a hole in chain case today.

D
Sep 30, 2012
42
7
8
02 RMK 700 with 1400 original miles. I blew a hole in my chain case today, case was lubed and chain was tight. When I got it apart the bolt holding the drive shaft sprocket sheared off and either it or the washer jammed in the case and knocked out a hole and ruined a great sunny day in North Idaho. Is this common? It seems like something that shouldn't happen.
 

MARV1

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Crap happens... Put loctite on your next bolt, the blue stuff. Do not over tighten it either otherwise it can break easily. And do not overtighten the chain, 1/4" slack on the back side back and forth.
 

sled_guy

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I've not seen them break, but I've seen them back out if they aren't blue loctited like Marv1 says.

Make sure the gears a lined up correctly, you can lay a straight edge across them to make sure.

sled_guy
 

Hardass

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Be sure before installing a new bolt with loctite to clean the hole out with a degreaser also the washer that is used there is a spring washer and is cupped on one side the cup faces the gear do not over tighten . I know others have said blue but i always used a small dab of red and then just snug enough to compress the washer slightly.
 

whoisthatguy

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I had the lower sprocket bolt break on me. They are supposed to be hi-strength bolts. I am pretty sure that mine snapped because I had over tightened it.
 

LoudHandle

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Replace the grade 3 stock bolt with a grade 8 for some piece of mind.

I had the lower sprocket bolt break on me. They are supposed to be hi-strength bolts. I am pretty sure that mine snapped because I had over tightened it.

They are not and never have been a quality high strength bolt. They come from the factory with grade 3 hardware, (cheap junk). Get yourself a grade 8 bolt so if you do get a little aggressive on the torque your not twisting it off.

P.S. Dustball27, Did you already get a new case? If not I have a few spares in the garage I can get in the mail to you for a little more than the postage fee.
 
Last edited:
D
Sep 30, 2012
42
7
8
They are not and never have been a quality high strength bolt. They come from the factory with grade 3 hardware, (cheap junk). Get yourself a grade 8 bolt so if you do get a little aggressive on the torque your not twisting it off.

P.S. Dustball27, Did you already get a new case? If not I have a few spares in the garage I can get in the mail to you for a little more than the postage fee.

Thanks for the info... I am putting in a grade 8 bolt. And thanks for the offer, but yes I already picked up a new case.
 
F

Flying Dutchman

Well-known member
Dec 14, 2007
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Red Deer
We just had this happen to a buddies machine, blew the whole bottom out of the case. Only thing we found was that the bolt head was sheared off and obviously got stuck in the wrong place. Fortunately we were able to clean up the shrapnel, and ride it out.

Not sure if you are replacing the chain, but check very carefully at every link for any cracks and breaks, etc.
 

Scott

Scott Stiegler
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I backed the bolt out of the bottom gear on my chaincase and wore a nice hole in the cover as it spun. Custom ported chaincase.
 
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