why does this brake? 3007-262

[coug66]

Part number 12? clutch side shaft on crank

Up at the top of Baker my crank breaks just behind the primary clutch.

This is where my Crank broke, climb up to top of Mt. Baker.

I believe its part number 12 (3007-265).The motor did shake at idle but smoothed out under throttle.

I am looking for help, where do I send my Crank to have number 12, replaced and the general crank inspected , balanced and gone over?

I would like to have my clutch balanced and reworked, my sheave face has some scuffing.

Has anyone found a way to prevent this from happening? what causes this?
In my mind I could never imagine how the extenal part of the crank can break?

How do I prevent this from repeating? sled has 1400 miles I have owned it for two weeks. it broke on my 3rd ride.

need clutch and crank repair advice.

 

[High Country]

i have heard.....A)out of balance and B)clutched over torqued(impact tools)

 

[m8magicandmystery]

high speed belt blowing will cause a crank to weaken there..


http://www.snowmobilecylinders.com/crankshaft_repair.html

 

[everytime5.9]

Agreed on improperly torqued/Fatigue from belt blow. Mine happened right after the ABC bolt install. And it's #12 BTW.

My sponsors Ebay and Visa had me up and running in no time...

 

[coug66]

Agreed on improperly torqued/Fatigue from belt blow. Mine happened right after the ABC bolt install. And it's #12 BTW.

My sponsors Ebay and Visa had me up and running in no time...

Does this happen with any other brand or cc of M sleds? I sincerely appreciate all your advice, I just want to be confident I can prevent this from reoccuring.





#12 you are correct! the key slot should have given me the needed clue.

I have edited the post.

Ian

 

[m8magicandmystery]

coug...you did notice the website for repairs..??
http://www.snowmobilecylinders.com/crankshaft_repair.html

 

[coug66]

coug...you did notice the website for repairs..??
http://www.snowmobilecylinders.com/crankshaft_repair.html

Yes, thanks that looks like a great site for the crank repair.

I need to get the motor removed and open and see if there is anything else to resolve.

Thanks,

Ian

 

[m8magicandmystery]

cat cranks are a rare problem imo..if ya get it fixed or replaced proper and no other issues you shoulld be able to sleep nights...just make sure ya get that primary balanced and in shape...Racinstation in this forum is a great guy to get ahold of reguarding your primary and balancing...and ya can check the crank options with him as well...pm him..

 

[coug66]

half way through goal to be up and running by Sunday.

I have bought a motor with a burned down piston.

I have dissassembled it and removed the crank.

I have removed my motor from my sled. I have the engine half way torn apart. Like a mountain climb I am doing the job in stages in the evening after work.

tommorrow night I should be able to finish the crank swap and put the motor back together. Once I have the motor reassemebled I will put the motor back in on Saturday.

hopefully I will have the sled back up and running on its one week anniversary next Sunday.

I have to say I am really happy that I had friends look after me and source a great deal on a used engine.

I really appreciate the deal the seller gave me on the engine. It was practically a gift.

Hopefully over the summer I can fix my crank and rebuild a second motor to be dropped in should a situation arrive where I need a second motor.

I think snowmobilers are a great group they are willing to help off and on the mountain. I only hope I can live up to the code with others as you set the bar really high.

I love this M1000 its amazing and I can't wait to get it going again up at Greenwater. Also I really like this power claw.

One challenge I have not resolved is the clutch. I have no idea how to get the crank out of the clutch. without a solid piece to push on a traditional puller won't get the job done.

I thought about getting a bolt and a big socket and bolting it tight from the crank side? the problem is the threaded bolt shaft is pretty large and the bolt won't fit through the big socket hole. plus I have some big sockets but the crank is much wider than my largest socket.

I just thought of something what If I used an old rotor?

anyway I need to get creative.

Ian

 

[98gtlights]

I would try warming the clutch up with a torch and use an air hammer to knock it out.

 

[morrisac509]

Water

Find a bolt that will thread into the clutch where the clutch puller would normally thread into, wrap the bolt threads with plumbers tape and fill the clutch up with water. Then thread the bolt in and hit with a air gun, probably will take a 1/2 inch gun. The hydraulic pressure should push the end of the crank right out. I have done it a few times and it has worked pretty good for me. Good luck

 

[coug66]

Sled is back running!

Well I managed to reassemble the motor and put it back in the sled!

Reattached everything, and now all I need to solve is the crank piece in the clutch issue.


Thank you so much for the information below. The rotor idea is a bust since it has a deep center shaft. And would not get any separation force.

I forgot about the hydraulic separation technique. I just bought a bolt and it would be easy to try it.

If I put the bolt in the crank base then I could try a traditional puller.

couple of options and thats just what I needed to get started on the remaining challenge keeping this sled off the mountain.

Thanks,

Ian

Find a bolt that will thread into the clutch where the clutch puller would normally thread into, wrap the bolt threads with plumbers tape and fill the clutch up with water. Then thread the bolt in and hit with a air gun, probably will take a 1/2 inch gun. The hydraulic pressure should push the end of the crank right out. I have done it a few times and it has worked pretty good for me. Good luck

 

[coug66]

It worked! crank removed from clutch!

Wow, I had tried this before on another sled with out much luck. ( I ended up cutting the clutch off)

The problem I always had was the tape would let the water around the threads and no pressure.

It took me several tries to get this to work.

I got a good wrap ( yellow tape) and hit the air wrench driver and pop.

I just need to clean up the faces on the clutch and re install.

Thanks again for the help,



Ian

 

[JMCX]

You need to get that clutch checked out as it is the most likely reason for your crank failure.

 

[coug66]

checked clutch and polished faces and torqued to spec.

I put the clutch on a tire balancer used for balancing motorcycle tires.

It has bearings on the shaft and I was able to spin the clutch for 20 seconds per medium spin. This is not my balancer but same concept. shaft and bearings pinching clutch from both ends to keep it centered.

If it was bad I would have had to replace the clutch, instead of add weight like a wheel.
unlike motorcycle tires I could not add weight, the clutch balance technology seems to be you remove weight from the heavy side.



The clutch has zero bias. It does not seem to have a heavy side. I was looking to see if it would stop at the same point for multiple spins. Each spin it stopped at a different location. I could stop it and it did not rotate to a heavy side.


Cleaned up the face to get ride of the scratches, torqued to spec and reinstalled primary and driven clutch.

I think the issue was belt breaking and prolonged fatigue.

The clutch was not (in my opinion) the cause.



Crank broken last Sunday and restored this Sunday!


Sled is back in action!


Ian

 

[m8magicandmystery]

willikers...when ya started this thread it seemed that you may only have limited skills with your question etc...but as each post goes by it is apparent that you have substantial knowledge and skills and the confidance as well....kudo's to ya...!!!!!...

so did ya do a crank run out measurement with clutch off and on..??...or is it needed..??

 

[coug66]

I have worked on Motorcycles since I was 13 years old. I am new to snowmobiles the track replacement was more intimidating to me than the crank.

I feel like I know the sled better now, not so intimidating anymore.

I had the Arctic Cat manual and its pretty complete.

I did not measure any runout?

I checked belt deflection and its OK.

Slowly burping the coolant system. I want to get all the air out before running it for any length of time.

hopefully I will be up at greenwater next weekend.

Ian

 

[m8magicandmystery]

enjoy and a safe and fun trip to ya...!!!!

 

[Paul27]

No two parts are exactly the same. And all steel parts contain internal and external flaws. It's just a matter of how many flaws, how big, and where they are located. To detect every internal flaw, in every part, is so expensive it's cost prohibitive and cheaper for every manufacturer to have a warranty program.

If you happen to be an unlucky buyer, who bought a machine with a part that contained a fatal flaw, which did not lead to failure within the warranty period, all you can do is replace the defective part and move on. Chances are the replacement part will not have a fatal flaw and will never break.

This comment does not dispute the other advice in this thread, which are 100% correct - more load from broken belts, over-torqued bolts, out-of balance components - those factors all increase the load on a defective part and hasten failure.

Fatigue is at work in all metal parts when they are loaded repeatedly above their "fatigue limit" (which is about 30 to 50% of yield strength for steel and near zero for aluminum). It's a phenomenon where microscopic flaws grow into cracks, which eventually lead to failure. Most engine parts are loaded above the steel fatigue limit. If not, your engine would weigh 400 lbs or more.

Good luck on your rebuild !!

 

[u2celk]

Crank breaks.

My crank did the same thing and I was offered up another suggestion. If you measure the length of the factory bolt that holds the primary on versus the depth of the hole in the crank you will find that the bolt is quit abit shorter. This leaves a farely good size void in the end of the crank and any out of balance is working on that area. Mine was replaced by a titanium crank bolt that was longer, but no so long that is bottoms out prior to torquing up, and I have over 5000 miles on this motor with out a bobble.
I am not saying this is the save all but it is a suspect area that can easily be fixed.
Just throwing my .02 cents out there.