Crankshaft Nut Maintenance Suggestions

NoVa Rider · 10-29-2016, 05:59 PM

I am not sure that there is a thread yet specifically on CSC's recommended crankshaft nut maintenance. CSC has a tutorial that covers the basics, but let me add a few notes.

CSC started recommending folks check torque on their crankshaft end nuts at 10,000 miles after one owner had a nut come off during operation, and I believe CSC found at least one other RX3 with the nut improperly torqued. Seems these incidents are rare and I have not yet heard whether the 2016 RX3's have had any issues with improperly torqued nuts. The maintenance is really "just in case."

I just had to replace my shift return spring at about 6,700 miles, and decided to check the crank nut torque since my engine right side cover was off anyway.

In my case, I think the nut was correctly torqued. But there is no way to check without undoing the lock plate, at which point you are kind of committed to removing the nut and installing a new lock plate.

My main comment is to be sure and have the correct lock plate on hand before starting this job. I found that the lock plate for the chain sprocket is not correct for the crank end nut. The chain sprocket inside diameter is about 16.5mm, but the crankshaft end nut lock plate is about 18.3 mm inside diameter.

Second, I had to use a 1/2 inch impact to remove the nut. I don't think there is any other way to get this nut off.

You'll also need a good 10mm allen head socket and a 1/2 inch breaker bar to hold the left side of the crank steady while you apply 100 ft pounds to the crankshaft end nut. Its a lot of torque!

CSC notes that its difficult to remove two allen head bolts that are at the rear of the engine side case. But there is no need to cuss. Just be prepared to use a 1/4 or 3/8 inch sharp chisel and a hammer, notch the edge of the bolts, and then tap them a bit counterclockwise to break them loose. A ball-end 5 mm hex wrench then can get them out the rest of the way.

Jay In Milpitas · 10-29-2016, 08:52 PM

Very good post, NoVa.
I will add that if you are not using an impact gun to tighten the nut, the gears of the crank and clutch can be *locked* by either a piece of aluminum bar wedged between the teeth or a special tool similar to this:
https://www.motionpro.com/product/08-0427

Hope this helps others.

Jay

NoVa Rider · 10-29-2016, 09:14 PM

And I forgot to mention, you need a 27mm socket for the nut, and I used a 1/2 inch "clicker" torque wrench to get the 100 foot pound torque that CSC calls for.

BlackBike · 10-30-2016, 10:16 AM

Quote:

Originally Posted by Jay In Milpitas

Very good post, NoVa.
I will add that if you are not using an impact gun to tighten the nut, the gears of the crank and clutch can be *locked* by either a piece of aluminum bar wedged between the teeth or a special tool similar to this:
https://www.motionpro.com/product/08-0427

Hope this helps others.

Jay

Good post yourself. For something that's as scary critical as getting this right, the right tool for the job is a must

kumatae · 11-08-2016, 05:06 PM

A bit late to the party but I did mine not too long ago and it was a pain! First tip is remove the two bolts with a chisel when the engine is warm. Made a world of a difference. I guess mine wasn't all that torqued properly because I was able to remove it without a lot of force. I had a 10mm hex socket on the left side and it naturally got caught on something and so I could loosen and tighten. Gerry from CSC told me that they use the same lock plate as the front sprocket. You just have to make the hole bigger using whatever tool you have. The part that kind of sucked was tightening the two bots that I removed and replaced with the same 8mm bolt. My open end wrench didn't quite do the job so I bought a cheap 8mm wrench and cut it in the middle so it was super compact and was able to tighten it just fine.

10-29-2016, 05:59 PM	#1
NoVa Rider Join Date: Jan 2015 Location: Northern Virginia Posts: 144	Crankshaft Nut Maintenance Suggestions I am not sure that there is a thread yet specifically on CSC's recommended crankshaft nut maintenance. CSC has a tutorial that covers the basics, but let me add a few notes. CSC started recommending folks check torque on their crankshaft end nuts at 10,000 miles after one owner had a nut come off during operation, and I believe CSC found at least one other RX3 with the nut improperly torqued. Seems these incidents are rare and I have not yet heard whether the 2016 RX3's have had any issues with improperly torqued nuts. The maintenance is really "just in case." I just had to replace my shift return spring at about 6,700 miles, and decided to check the crank nut torque since my engine right side cover was off anyway. In my case, I think the nut was correctly torqued. But there is no way to check without undoing the lock plate, at which point you are kind of committed to removing the nut and installing a new lock plate. My main comment is to be sure and have the correct lock plate on hand before starting this job. I found that the lock plate for the chain sprocket is not correct for the crank end nut. The chain sprocket inside diameter is about 16.5mm, but the crankshaft end nut lock plate is about 18.3 mm inside diameter. Second, I had to use a 1/2 inch impact to remove the nut. I don't think there is any other way to get this nut off. You'll also need a good 10mm allen head socket and a 1/2 inch breaker bar to hold the left side of the crank steady while you apply 100 ft pounds to the crankshaft end nut. Its a lot of torque! CSC notes that its difficult to remove two allen head bolts that are at the rear of the engine side case. But there is no need to cuss. Just be prepared to use a 1/4 or 3/8 inch sharp chisel and a hammer, notch the edge of the bolts, and then tap them a bit counterclockwise to break them loose. A ball-end 5 mm hex wrench then can get them out the rest of the way.
	3

10-29-2016, 08:52 PM	#2
Jay In Milpitas Join Date: Jul 2015 Location: Milpitas, CA. USA Posts: 775	Very good post, NoVa. I will add that if you are not using an impact gun to tighten the nut, the gears of the crank and clutch can be locked by either a piece of aluminum bar wedged between the teeth or a special tool similar to this: https://www.motionpro.com/product/08-0427 Hope this helps others. Jay
	0

10-29-2016, 09:14 PM	#3
NoVa Rider Join Date: Jan 2015 Location: Northern Virginia Posts: 144	And I forgot to mention, you need a 27mm socket for the nut, and I used a 1/2 inch "clicker" torque wrench to get the 100 foot pound torque that CSC calls for.
	1

11-08-2016, 05:06 PM	#5
kumatae Join Date: Oct 2015 Posts: 51	A bit late to the party but I did mine not too long ago and it was a pain! First tip is remove the two bolts with a chisel when the engine is warm. Made a world of a difference. I guess mine wasn't all that torqued properly because I was able to remove it without a lot of force. I had a 10mm hex socket on the left side and it naturally got caught on something and so I could loosen and tighten. Gerry from CSC told me that they use the same lock plate as the front sprocket. You just have to make the hole bigger using whatever tool you have. The part that kind of sucked was tightening the two bots that I removed and replaced with the same 8mm bolt. My open end wrench didn't quite do the job so I bought a cheap 8mm wrench and cut it in the middle so it was super compact and was able to tighten it just fine.
	1