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Post by joneill4 on Sept 11, 2008 11:06:55 GMT -5
I was riding home from work last night taking the scenic route as usual. I was following a mini van that was going the posted 45mph in an area where no one obeys the speed limit. A nice shiny black Audi rolled up behind me doing about 75 mph. He never actually tail-gated me, but he was just inside of my comfort zone. My Super-Trapp exhaust has several stress fractures and holes in it, so when I heard a grinding noise I figured the muffler was dragging the street. I looked back and the muffler was fine. I down shifted and nothing happened. The guy in the Audi was now well within my comfort zone, so I hit the grass shoulder much faster that I cared to. I got her stopped and looked down at the counter sprocket cover only to see oil gushing out. I figured the chain must have come off of the counter sprocket and broken the transmission case.  I shut her off, found neutral, and started a long long push. I pushed for over ten miles to get to a pay phone. Thank God the phone was in front of a liquor store. I got a ride home for me and the bike, but I figured it was a lost cause so I got good and drunk. I went to bed thinking that I had ridden my baby for the last time. This morning I went out and pulled the sprocket cover off. The freakin' nut was missing! That allowed the sprocket to slip of of the splines and the counter shaft seal to come out! I thought she was dead, but she will be back on the road for $10 or so.  In the way to work this morning, I thought I would try to find the nut. Long shot I know. I could see where the oil was leaving a tire track. I kept going and realized that the entire time the Audi was behind me, it was getting drenched in oil. I left a track over a mile long.  |
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Post by soonerfan on Sept 11, 2008 13:04:06 GMT -5
Another testamonial to the legendary ruggedness of the Yamaha 500 single. If you find the nut it will be a miracle, especially if it is unscathed.......but, look on the bright side:
1. You didn't get hurt (except for the hangover and sore legs).
2. Bike will recover.
3. Time for an oil change anyway, and a good bath.
4. Another good tale for the grandkids.
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Post by StewRoss on Sept 12, 2008 1:27:45 GMT -5
10 miles!!! I too learned this, many years ago now of course...lucky it didn't go all over your rear tread and put you down the road. I bet the guy with the Audi was cursing you...after having to re-polish his now oil-spattered car, heh, heh...he probably doesn't appreciate that you have just rust proofed his car for free of course...  Usually this happens for one of two reasons: - Either the nut wasn't tight enough, or
- The lockwasher wasn't used or incorrectly located on the splines...which I reckon is the most usual reason when this happens.
Always make sure that when the washer is on it is correctly located on the splines. There is not much to locate the washer on the spline with the 530 sprocket, so to make sure, position the nut and washer finger tight, then back off the nut a tiny bit, just enough to loosen the washer a little. Then try to rotate the washer with your finger tips...with it almost clamped up by the nut it should't rotate...just move on the spline. Another small thing is that if you've tightened up the nut onto the washer and it hasn't been correctly located in the splines, it can bend the little spline tabs outward...this makes it difficult or almost impossible to re-use as it now can't lock in. You can tap them flat with a mallet or similar if they're only bent a small amount. In my mind it is usually better to replace it each time you change the sprocket, just to be sure...  I reckon a lot of guys would have done the same thing...or is just you and I??? SR |
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Post by joneill4 on Sept 12, 2008 11:50:46 GMT -5
I spent some time trying to figure what went wrong. I did use a new washer when I put the new sprocket on, but I didn't have a socket to fit the nut. With no socket, I couldn't use my torque wrench. If memory serves, I actually had to use an adjustable wrench. Also, I don't think I've taken the sprocket cover off since I put the sprocket on. I have been feeling this strange vibration in the chain for a few weeks (I know I know I should not have been riding it) I tightened the chain, loosened the chain, carefully aligned the chain...just never thought to look at the front sprocket. So, to avoid this ever happening to me again, I will go out and buy the proper socket and torque to the proper setting.
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Post by chew652 on Sept 12, 2008 13:37:49 GMT -5
Also peen the locktab over completely over the length of the flat on the nut. You would be suprised how easily the nut can rotate past that tab if there is just a slight bit of clearance. Don't ask me how I know this .
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Post by joneill4 on Sept 13, 2008 11:51:53 GMT -5
Well I didn't get off quite as easily as I thought. The threads on the counter shaft are all mashed flat. Does anyone out there know the size and pitch of those threads?
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Post by alancase on Sept 13, 2008 23:07:51 GMT -5
Exactly the same thing happened to me in 1986 (the last year my bike was registered) pushed it into a shed where it stayed till just recently when I started to restore it. I ended up fitting a new gear box shaft to fix the problem of the mashed threads.
Regards Alan Case
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sven
Full Member
Posts: 166
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Post by sven on Sept 14, 2008 2:59:55 GMT -5
Well I didn't get off quite as easily as I thought. The threads on the counter shaft are all mashed flat. Does anyone out there know the size and pitch of those threads? M18x1 (18mm o.d., 1.00mm pitch). Hard to repair with the shaft assembled. You can't (or shouldn't try to) recut this thread for the famous german metalworkers' saying: "Was weg ist ist weg." Regards Sven |
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Post by joneill4 on Sept 24, 2008 6:32:18 GMT -5
Well I think I've got her back together. I'll find out in about an hour when I go to work. The nut was $4. The die was $16, but the shipping was $12. The 1 1/4 socket was $2. Not too bad when you consider that I almost pushed her into the weeds and walked away!
SCM, thanks for the info on the shaft. I understand what you are saying, but it wasn't really that bad. I didn't even have to use a wrench on the tap.
Anyone know what the torque value is supposed to be? I couldn't find it in my manual. Mark from Thumperstuff said he thought it was 85ft lbs, so that's what I used.
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I shut her off, found neutral, and started a long long push. I pushed for over ten miles to get to a pay phone. Thank God the phone was in front of a liquor store. I got a ride home for me and the bike, but I figured it was a lost cause so I got good and drunk. I went to bed thinking that I had ridden my baby for the last time. This morning I went out and pulled the sprocket cover off. The freakin' nut was missing! That allowed the sprocket to slip of of the splines and the counter shaft seal to come out! I thought she was dead, but she will be back on the road for $10 or so. 
In the way to work this morning, I thought I would try to find the nut. Long shot I know. I could see where the oil was leaving a tire track. I kept going and realized that the entire time the Audi was behind me, it was getting drenched in oil. I left a track over a mile long. 
