crankshaft nut thread primary side counter clock to loosen?

E

Evan

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Texas
Nut Won't budge. The inside lock washer lip is pulled back. I had done this before & as I remember its left turn to loosen. Right turn to tighten. It is Not right turn to loosen like the starter clutch side. I had thought Laverda had it this way for the centrifugal force. Green book doesn't say anything about Crankshaft thread direction primary side. Heated w/ heat gun. Tried by hand w/ breaker bar. Tried impact wrench. It has been removed before (not by me) & maybe they used Red threadlock. Any suggestions?
 

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If you suspect thread lock then just heat it up (paint stripper gun is enough). Any decent rattle gun should do it as long as the air supply is sufficient. Battery powered rattle guns today can be very powerful too, I used one to remove that nut today on my engine. DO NOT be tempted to put anything between the sprockets to lock it.
 
Tippie said:
If you suspect thread lock then just heat it up (paint stripper gun is enough). Any decent rattle gun should do it as long as the air supply is sufficient. Battery powered rattle guns today can be very powerful too, I used one to remove that nut today on my engine. DO NOT be tempted to put anything between the sprockets to lock it.
Click to expand...
+2000 Nm nutbusting on the cordless used Sat without needing to lock the flyweel ( on a ducati). Pissed it in. Highly recommended tool.
 
Thanks. I have a chain wrench I could wrap around the clutch housing. I'm sure it would lock it but scar the surface. I don't know if that would be wise. Think that would be Ok? I'm paranoid about holding the starter clutch nut as it could tighten that side to strip threads! Impact wrench seems the best way...I did spray Rust Blaster in the Crankshaft groove & checked w/ a utility knife blade around the circumference of the nut since the 1st post. Arghhh!!!!!!!!!!! Leave it until tomorrow...
 
Evan said:
Thanks. I have a chain wrench I could wrap around the clutch housing. I'm sure it would lock it but scar the surface. I don't know if that would be wise. Think that would be Ok?
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No. It's not worth trying to do it by locking the clutch. There's a gear ratio of just over 2:1 between crank and clutch so you'll have to apply twice as much torque to the clutch to hold it against the torque on the crank nut. If it takes 200Nm to undo the nut, there will be a tension of about 5000N on the chain. That's half a ton. The chain should handle a static load of that much, but you could bugger the clutch or bend a shaft.

There is a factory tool that locks the crank, but an impact wrench is a far more practical way to undo the thing. It's worth buying an impact wrench. They're not expensive, typically less than $100 for a cheap brand, which will be perfectly adequate for occasional use. I bought a cheapo pneumatic rattle gun a few years ago and I've been surprised at the amount of use it gets.

BTW, if you're ever in doubt about which way a nut goes, just have a look at the exposed bit of thread (if there is any). The answer will be obvious.
 
Evan said:
I'm paranoid about holding the starter clutch nut as it could tighten that side to strip threads! Impact wrench seems the best way.
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Don't use the starter clutch nut (which is reverse thread by the way), it has a far smaller shaft size than the LHS. The inertia in that big heavy crank is enough with a rattle gun. For comparison, I do the starter clutch side up with two or three sharp whacks with my nylon hammer on the socket bar (against crank inertia/compression), and the primary sprocket nut up with my rattle gun until it stops. Pneumatic rattle guns need a lot of air supply, if the hose internal diameter is a bit small or the hose is long, they lose a lot of their power. Many tool suppliers rent tools if you can't afford one, but needed also for when you re-assemble it.
 
Ok I just saw a chain wrench won't fit in there anyway. Don't know what I was thinking. Its cold here in Texas this wk. I'll try more heat later.
 
its obvious that you are losing the torque by not having the factory tool (or an aftermarket) that locks the crank, it fits onto the teeth of the oil pump drive, is usually long enough to work with a good ring spanner and (scissor like ) bring them together, occasionaly, it is worth extending the locking tool to the ground using a sleeve of some sort,and using then,your foot on the spanner, plenty like the rattle gun, I do as well, but I have never owned my own.
CLEM
 
the factory tool would be ideal too Clem. I've drilled my primary sprocket and will make a tool akin to the triple version. I just reckon when the owner is risking using a chain wrap device around the clutch then they're obviously not looking at a factory tool solution and it might be a good idea to get a good budget rattler.
 
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