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Discussion Starter #1
Engine off. I put bike in gear it will roll 2 1/2" before the ring and pinion gears( final drive) mesh together again . I can't believe this is normal. Does anybody have this situation. Splines are all fine I lubed at 5700 mi.
 

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Linkmeister Supreme
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Engine off. I put bike in gear it will roll 2 1/2" before the ring and pinion gears( final drive) mesh together again . I can't believe this is normal. Does anybody have this situation. Splines are all fine I lubed at 5700 mi.
Well actually the final drive gears are always "meshed" together.
What you are describing is backlash, freeplay or slack.

The 2 1/2" movement is take up of backlash between gears in the whole drivetrain from the engine, transmission, front bevel gear assembly, driveshaft and final drive. I have never measured the freeplay or backlash in the drivetrain on my bike, but IMHO if you are not experiencing any serious "clunking" when you shift into gear, I wouldn`t worry about any perceived looseness.:)

BTW, welcome to the Vulcan madness.
Is the 750 your first motorcycle?
How long have you been riding? How many miles so far?
 

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Discussion Starter #3
Ring & Pinion

Well actually the final drive gears are always "meshed" together.
What you are describing is backlash, freeplay or slack.

The 2 1/2" movement is take up of backlash between gears in the whole drivetrain from the engine, transmission, front bevel gear assembly, driveshaft and final drive. I have never measured the freeplay or backlash in the drivetrain on my bike, but IMHO if you are not experiencing any serious "clunking" when you shift into gear, I wouldn`t worry about any perceived looseness.:)

BTW, welcome to the Vulcan madness.
Is the 750 your first motorcycle?
How long have you been riding? How many miles so far?
The clunking in the shifting is what lead me to measure the freeplay the way I did. I removed the fill cap on the final drive and rotated the rear tire, the pinion gear does not turn but the ring gear does turn one full tooth on the pinion.
I have 7300 miles on the bike now.

Actually I had (2) bikes in the 60's a Triumph cub and a Suzuki x six hustle.
Since the mid 90's I have been riding and restoring Cushman's

They say knowledge is power, I hope their right!
 

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Linkmeister Supreme
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It sounds almost, but not quite, like you are describing a broken tooth on a gear.
I`m stumped at the moment.:confused:
 

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If only it had 6th gear..
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Seems like maybe the side tolerance between the pinion and ring mesh is too wide. Can you describe the clunking a little more? Like does it ever happen during acceleration? I'll try to check mine before I go to work in the morning and see how much play it has.
 

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Discussion Starter #6
Ring & Pinion

Seems like maybe the side tolerance between the pinion and ring mesh is too wide. Can you describe the clunking a little more? Like does it ever happen during acceleration? I'll try to check mine before I go to work in the morning and see how much play it has.

The tolerance between the ring and pinion is what I have been thinking, but since clymer's tells me you need special tools to work on the final drive!!!!!!!!!!

Clunking is only at shift, if I time things right, which is only about 50% of the I can avoid the clunk.
 

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Discussion Starter #8
Ring & Pinion

Seems like maybe the side tolerance between the pinion and ring mesh is too wide. Can you describe the clunking a little more? Like does it ever happen during acceleration? I'll try to check mine before I go to work in the morning and see how much play it has.

The tolerance between the ring and pinion is what I have been thinking, but since clymer's tells me you need special tools to work on the final drive!!!!!!!!!!

Clunking is only at shift, if I time things right, which is only about 50% of the I can avoid the clunk.
 

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Old Truck Junkie
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I think you are worrying about nothing. 2 inches a small amount of travel. Imagine a slice of pizza. As you get closer to the center the movement gets less and less.
At 7300 miles it is very unlikely to have any trouble in that area. However, you can check for metal grindings in the oil. Use a magnet tool retriver in the gear oil and check it for metal.
Hope this gives you peace of mind.
 

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Engine off. I put bike in gear it will roll 2 1/2" before the ring and pinion gears( final drive) mesh together again . I can't believe this is normal. Does anybody have this situation. Splines are all fine I lubed at 5700 mi.
Put the bike on the centerstand and in first gear. Rotate the tire until the gears mesh. Then rotate the tire in the opposite direction. Measure this freeplay amount. If within 2-3 inches I wouldn't worry about it.
 

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Discussion Starter #11
Thanks, For all of the input. We are gonna let'er ride, for the next 1600 mi. Next week she's doing the Lake Superior bike tour!
 

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Im still learnin bout my Vulcan.... But after 23 yrs biuldin axles for Dana, I know differentials and thats alot of backlash... Dont know what the specs are for the Vulcan but i can tell you I have never built backlash with more than .008 of play between ring gear and pinion... that being said, it will still last a long time... We have tested axles with known backlash with 100 mls on them and that 8 thousanths will turn into 20 thou... My 2 cents..:beerchug:
 
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