| Author | Message | ||
     Petey293 |
2002 X1, 36000 miles, I've got a loose crank rotor nut So the first time the nut came loose I put it back on "tight" while listening to the voice in the back of my head telling me to not over tighten it. I had a torque wrench but it didn't go that high haha. It came loose again the next day... I went back at it with a proper torque wrench, cleaned the nut threads, cleaned the crank threads, red loctited and torqued to proper spec. I believe I used the revised higher torque. It held together for a few months but now it's loose again! What gives? It seemed fine last time I was in there, but is it possible the crank is damaged from riding it back home with the sprocket loose? Thanks for the help guys! | ||
| Buelliedan |
I use lots of red loctite and torque to 215 ft lbs. Hopefully you did not booger up the threads as that is very bad. | ||
| S1owner |
Whats the crank rotor nut? | ||
| Harleyelf |
The big nut above the front end of the primary chain. It's on the crank and above the alternator's rotor. When it comes loose, the chain rubs the inside of the primary case and makes a horrible noise. | ||
| Petey293 |
I guess it's possible the threads could have been damaged. I would think the splines would keep the rotor on the crank well enough to at least keep it from chewing up the threads, but I'm not sure. I suppose I'll be taking it apart soon anyway to check it out. I saw on the XL Forum they recommend 260 ft lb or higher for the Buells, not sure how much higher they're thinking but if I can safely take it up to 260 then I think I'll just soak the thing in red loctite and do that. I remember now that I used the red loctite GEL last time I put it on, I may just get some new fluid this time instead of using the gel, unless it can be trusted. Thanks for the advice guys, this place is awesome! | ||
| Buelliedan |
I use the red gel and never had an issue. | ||
| Johnod |
I think I torqued mine to 200lbs, and Loctite of course. Maybe buy a new nut too, cheap enough, can't hurt anything. | ||
| Upthemaiden |
I think I remember hearing the increased torque number of that bolt was just for the XBs. Don't quote me on that. Obviously a slightly over torqued bolt is better than your front sprocket rattling off. | ||
| S1owner |
Not being familiar with this exact issue but alot of nuts and bolts can only be used once. When a nut is properly torqued it stretches the threads on either the shaft or nut. The specified amount to torque is how much you are stretching. If this nut has been over torqued it could simply beed a new nut installed per factory specs. | ||
| Tootal |
When I did mine I used brake cleaner to remove the oil and then a rotary wire brush on a Dremel to get all the old loctite off. Then I cleaned it with brake cleaner again. I did the nut the same way. One drop of red loctite on the crank, one in the nut and proper torque and never any problem. Getting it perfectly clean is necessary. Prefit the nut on the crank before adding the loctite. It should not rattle or have much play. If it does replace the nut. | ||
| Zac4mac |
There are no stretch bolts on Harleys. The rotor nut on the 1125s is the closest I know of. That nut is slightly cupped but can be used 3 or 4 times. Always clean the old loctite from a high torque fastener completely, re-install with fresh loctite. The 1125 rotor nut takes 300 ft-lb torque, feel lucky with only 205. | ||
| Phelan |
The tuber nut cannot get the larger torque spec because the left side crank bearings are Timken tapered rollers, not the INA bearing in the XB and 04-up XL, Twin Cam. | ||
| S1owner |
Zac All bolts “stretch”. Its not the bolt stretching but the threads. Thats what happens as you torque the nut down. Its also why they say never reuse a bolt that has been torqued. | ||
| Screamer |
If the engine has run too many miles with a loose nut, the splines (usually the rotor, not the sprocket shaft) may have been worn. If that has happened it will be difficult for the nut to stay torqued, because the back and forth rotation of the rotor may loosen the nut. If the nut has come loose - it should be replaced, because the threads may be compromised or the seating face of the nut may be damaged due to the fretting that may have taken place (when loose). There was a brief period where a (supplier provided) incorrect interference-type of sprocket nut was used, A bulletin was released to identify and address the suspect sprocket nut. Although no problem nuts were sold as service parts, it possible a few (used) could be floating around. The suspect nuts were identified by arrow shaped indentations on the outside (visible when installed) face of the nut. Correct torque is 190-210 ft lbs, with red loctite. There are several fasteners on Buells and Harleys that are considered "one-time-use", and are recommended to be replaced each time they are removed - due to "stretch". | ||
| Mike_lee |
considered "one-time-use", are the 10mm shock bolts/nuts one of these? | ||
| Upthemaiden |
I think you'll be fine with the shock bolts. If I remember correctly, I think they're only rated at around 40ft/lbs, so I don't think the threads are stressed too much. If you do look at replacing them, I *think* they were 12mm bolts, not 10mm. | ||
| Mike_lee |
I just swapped the shock on the S1 yesterday. They were indeed 10mm allen heads. | ||
| No_sprk |
FYI i just bought a m2 engine for parts because the nut came loose and the splines ended up stripping. so its not just a isolated incident | ||
| Upthemaiden |
Are you referring to the ones that bolt the shock to the front mount and the swingarm? Wonder if there were different setups between the different years? I just replaced mine this winter because I swapped from the steel swingarm to the aluminum one and needed the longer bolt. I checked my ebay purchase history and I used a 12mm x 1.75 x 55mm bolt. | ||
| Mike_lee |
Correct Maiden. Not sure of length or pitch, but was def 10mm socket head. These were new bolts from SP HD. I havent checked the x1 bolts, those could possibly be the same as yours. Sry if i hijacked the OP’s thread  | ||
| Tootal |
Question: Are you guys talking about the same thing? Does a 12mm thread use a 10mm socket? | ||
| Upthemaiden |
"Does a 12mm thread use a 10mm socket?" Looks like we have a winner  | ||
| Tootal |
I thought so, just too lazy to go look! Thanks Upthemaiden! | ||
| Mike_lee |
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| Petey293 |
Hey guys, it's been YEARS I know, but just wanted to update in case this thread comes up in any searches. I remember the threads at the very end of the crank were a bit chewed up, but I took the bolt off, cleaned the threads on both the crank and the nut very well, then used the red loctite liquid and took it to ~250-260 ft.lbs. it's held ever since and I've had no issues. One stupid thing, I dropped the crank rotor and the magnets for the stator cracked and broke. I got a sportster rotor off of ebay, I think it was 1 or 2 teeth less than the Buell part. It works fine, my tensioner is about at the limit with the smaller tooth count though | ||
| _buelligan_ |
Tubeframe buells/solid mount Sportsters use 35 teeth rotor sprocket, 2004 and up Sportster rotors will work but will change your engine speed to transmission ratio, 883 models use 34 teeth and the 1200 models use 38. Same goes for the 2003-2007 XB’s, XB9 = 34T, XB12 = 38T. Most XB12 owners will swap the OEM 38 for a 34 to gain more low end torque. 2008-2010 XB’s have a larger crank snout and will only fit those year XB’s and all XR1200’s. Going from 35 to 34 probably won’t feel much difference but if you want to keep the gearing ratio correct you can just buy any Sportster rotor, unbolt the sprocket and use a shop press to swap the sprocket gears from old to the new rotor. |
