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Front sprocket nut won't come off. Suggestions?

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Hi All,

I just got an 03 DRZ400 off of craigslist and it had the notorious leaky countersprocket seal that comes with these bikes. At this point, I'm trying my hardest to take the front sprocket nut off and I'm terrified of breaking the countershaft somehow. I can see that the nut is being held on with blue loctite and it is torqued down pretty good (over 70 foot pounds for sure). What is the best way to get this nut off without harming my drive shaft? Should I invest in an impact driver?

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Let some penetrant sit on it overnight, some P'Blaster or something. The next day, bend the lock washer out of the way, and torch the nut a bit to break the loctite. Then with the rear wheel on the ground and the bike in gear, try to loosen it with a breaker bar. You may want a buddy to hold the rear brake down if it really is that tight. If you know how to go slow use a wrench, you shouldn't round off the nut very much if at all.

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If your running into loc-tite bond issues, GENTAL heat will loosen up the compound and makes it easier to remove.

In your case, the seal and bushing will need replaced, so your not as worried about over heating the seal causing damage, but keep in mind there is a large bearing behind the seal that requires splitting the case to replace. Don't go wild with the map gas, just slowly heat her up and then hit it with impacts rather then a slow gorilla arm. If you have one handy, an impact driver (hand held hammer type) or a air impact gun will do you wonders.

I personally put the bike in neutral, brace the bike, then get your biggest buddy to stand on the rear brake as you impact the nut off the spline. Also may be stupid question to some.... but did you fold back the lock washer already?

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1 minute ago, RC_ichard said:

If your running into loc-tite bond issues, GENTAL heat will loosen up the compound and makes it easier to remove.

In your case, the seal and bushing will need replaced, so your not as worried about over heating the seal causing damage, but keep in mind there is a large bearing behind the seal that requires splitting the case to replace. Don't go wild with the map gas, just slowly heat her up and then hit it with impacts rather then a slow gorilla arm. If you have one handy, an impact driver (hand held hammer type) or a air impact gun will do you wonders.

I personally put the bike in neutral, brace the bike, then get your biggest buddy to stand on the rear brake as you impact the nut off the spline. Also may be stupid question to some.... but did you fold back the lock washer already?

Yeah, I plan on replacing the seal and the metal bushing with the o-ring inside. Yes, I've folded back the lock washer. When heating up the nut, do you heat directly with a torch or indirectly? Should I be worried about the heat causing damage to that bearing? I'm stopping by my uncle's mechanic shop tomorrow to borrow his impact driver.

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You mentioned 70 ft# for the front sprocket nut torque. The service manual specifies 80 ft#. And correct me if I'm wrong but since this nut still comes loose at this setting with the loctite, doesn't TT usually recommend a higher torque setting? Not sure of that value. 

 

sprocket torque.png

Edited by HansLanda

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You mentioned 70 ft# for the front sprocket nut torque. The service manual specifies 80 ft#. And correct me if I'm wrong but since this nut still comes loose at this setting with the loctite, doesn't TT usually recommend a higher torque setting? Not sure of that value. 
 
59543c4577d1a_sprockettorque.png.63b3d98370990ef3151ba32532049514.png

https://www.thumpertalk.com/index.php?/topic/540670-Counter-Shaft-Sprocket-"Loctite-Fix"
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I need clarification of the problem.  Is the problem holding the rear wheel?  Or you don't have a wrench long enough?  Updated torque for the nut is 100 ft lb. Standard right hand thread. Broken countershafts are not unheard of but it is not from tightening or loosening the nut.

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This is a classic example of why I will not use Loc-Tite on anything I own , well except the very few internal motor items that it's best. I quickly put a locking nut on mine and it's been nice and easy to remove yet stays where I put it without needing heat or extremely high torque numbers .

 

I believe this is the size , been a few years ,

http://www.partzilla.com/parts/detail/honda/HP-90231-HN8-A60.html?CAGPSPN=pla&gclid=Cj0KEQjwp83KBRC2kev0tZzExLkBEiQAYxYXOq6p079lHTHNdRGHyTu8rYE48eqOujgor6HPM7k6kH0aAj7E8P8HAQ

http://www.ebay.com/itm/BOLT-LOCK-STYLE-AXLE-NUT-22mm-x-1-5mm-KX125-KX250-KX250F-KX450F-CRF-KXF-RMZ-YZF-/291880925974?epid=625591623&hash=item43f5757b16:g:S1kAAOSwM4xXYRH1&vxp=mtr

 

 

.

Edited by jjktmrider

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Make sure the bike is in gear when you are trying to break the nut loose.  Highest gear will be the best as it has the least amount of torque multiplication and will help your rear brake hold the transmission from rotating.  Heat on thread locking compounds works wonders and it doesn't take much.  A plumbers propane torch should do the job.  Apply the heat to the nut as that is what you want to expand and has the least heat mass of the components.

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Use the force.... I mean fcken jump on that breaker bar. It will come off.

I have a small breaker bar but some metal pipe that fits over the end to get the really tight nuts off. My wr was the same. Someone on rear brake and in gear. IT felt so easy with the extension bar compared to the normal bar. Leverage!

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1st gear is the most effective holding the countershaft with engine compression but frankly it is of little help.  5th gear if you are trying to hold the clutch nut with the rear brake. The rear brake will usually work but it will only hold abut 100 ft lb.  Of course that depends somewhat on what gearing you are running.  Rear brake will hold SM 15/41 much easier than E 14/47.  An effective way to lock the rear wheel is to insert a screwdriver thru the brake disc so it bears on the brake pads (this only works to loosen the countershaft nut)  Important that the lock pin only bears on the brake pads that have a sold anchor directly into the caliper bracket  I really doubt any blue Loctite is doing much to hold the nut.

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3 hours ago, jjktmrider said:

This is a classic example of why I will not use Loc-Tite on anything I own , well except the very few internal motor items that it's best. I quickly put a locking nut on mine and it's been nice and easy to remove yet stays where I put it without needing heat or extremely high torque numbers .

 

I believe this is the size , been a few years ,

http://www.partzilla.com/parts/detail/honda/HP-90231-HN8-A60.html?CAGPSPN=pla&gclid=Cj0KEQjwp83KBRC2kev0tZzExLkBEiQAYxYXOq6p079lHTHNdRGHyTu8rYE48eqOujgor6HPM7k6kH0aAj7E8P8HAQ

http://www.ebay.com/itm/BOLT-LOCK-STYLE-AXLE-NUT-22mm-x-1-5mm-KX125-KX250-KX250F-KX450F-CRF-KXF-RMZ-YZF-/291880925974?epid=625591623&hash=item43f5757b16:g:S1kAAOSwM4xXYRH1&vxp=mtr

 

 

.

Right on Brother!  And once the OP gets the nut off, he may need a puller to get the sprocket off if it was like my bikes PO, with red locate all over the splines. I won't use that stuff either and haven't had the nut come loose in 3 years 18,000 kms. Though I change my front sprocket for different  gearing at times.

20170628_213410.jpg

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13 hours ago, LoLoSama said:

And for the future invest in an impact gun, it really make life easier.

.............and a high quality compressor. :thumbsup:

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I question the torque spec was generic based off the large size of the shaft and nut  vs. what that nut actually has to do.  Using folding lock washer I've tightened only with small trail tools for quick mid trip sprocket size changes, done it on 2 bikes never a problem in 10's of thousands of miles. 

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The clamp load of the nut affects more than the sprocket if you would read the link I posted above.

I have an aftermarket sprocket that seems to fit a bit tighter. I still put a drop off loctite on though. I experienced the loss of clamp load with the stock sprocket about 7000 miles ago. Happened around the 13k mark. The phenomenon is real. Retorqued to 100 ft-lbs and didn't feel any bind. I assume the 2nd gear bushing wasn't too worn. If the tranny does ever let go, I will finally have a reason to buy the ACT kit and stroker crank.

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Just did this to my klx250 2012 5,000 miles never been changed, exact same parts as drz. Used a long torque wrench in 1st gear on the brake broke it loose myself. It was tight, broke it loose at 92 ftlbs. Bushing will be hard to get out. I used emery cloth wrapped around outer edge of bushing with good new channel locks rocking back and forth.

Replace the oring behind the bushing mine was baked and a bugger to get out and flaked into pieces. Had to use a pick to get all the pieces out of the groove. Had to use emery cloth lightly on bushing to clean baked oil off, just don't sand it down.

Drove the seal in with a large socket maybe 1-3/8". Was hard to get straight and finally used a punch lightly to seat it past the bevel edge in the case hole just below flush. Stay on the outside edge if you have to use a punch or you'll jack the new seal.

 I take really good care of my bike and was surprised how baked the oring was. I use top end race oil as well. 

Good luck be patient you will get it. I wouldn't use heat the bearing behind it is sealed and has a rubber coating on it.

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