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Is my driveshaft...um... backwards?


rydfly

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Hello all, I bought my first Guzzi a few weeks ago. It's an '03 LeMans of unknown mileage (speedo replaced, no records to reference).  All signs so far point to it having been a neglected bike with lots of deferred maintenance I'm sorting through.  Right now the driveshaft has my attention.  I intended to pull it off the bike to get a good look at the spline conditions at both ends.  In the process I've come across a few things that I need your help to gain knowledge about.

1) first off... is my driveshaft installed backwards?!  Is that even possible? (and if so, could anything be damaged as a result?)

image.png

 

Looking at the parts diagram, it appears the O.D. of the front section is smaller than the O.D. of the rear section.  Or to put it another way, the end that connects to the engine/transmission has the grease zerk on the shaft, and the end without the grease zerk installs to the final drive.

As you can see in the attached pictures though, on my bike the shaft section with the zerk on the shaft is connected to the final drive, and the larger O.D. section is installed to the engine/transmission.

2) I have the pinch bolts completely removed from the yoke on the final drive but I still can't pull the yoke off the final drive input shaft.  What could be holding it on still?  Is it OK to apply some "persuasive force" to get it apart?

3) I've seen lots of warning both on this forum and in the owners/service manuals about the necessity to make sure the alignment marks on the driveshaft are, well, in alignment... but what occurs if they aren't aligned?  I ask because mine were indexed at least 60-degrees apart before I separated the driveshaft and I have no idea how long it had been run that way.

These are the first of many questions to come but they're the brightest burning ones right now in this maintenance adventure.  Thanks in advance for your help!

driveshaft - front section.jpg

driveshaft - rear section.jpg

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My bike has always been the same as your bike. I don't plan to change it. The open end of the centre sliding spline faces back, so less road spray can get inside, but spline lubrication may be slightly worse with the grease nipple at the low end. 

As for alignment of the 2 halves of the shaft, the yokes on the shaft must be on the same plane, and the yokes on the gearbox/transmission at each end also on their own plane which is 90° turned. If it is wrong, your gearbox, shaft, and rear transmission feel torsional vibration. This would be bad.

See the video pointed out by @Chuck https://youtu.be/5aCK4Bob6a0

 

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Same as what docc? The pictures or the diagram? Mine had the female spline off of the gearbox, just like the diagram. That is the shorter piece with the grease zerk. I marked mine before I removed it. It was not lined up with the factory white marks...almost 90° off. The yokes were not on the same plane. If I put it back to the marks, they are. It's a phenomena. :huh2:

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21 minutes ago, activpop said:

Same as what docc? The pictures or the diagram? Mine had the female spline off of the gearbox, just like the diagram. That is the shorter piece with the grease zerk. I marked mine before I removed it. It was not lined up with the factory white marks...almost 90° off. The yokes were not on the same plane. If I put it back to the marks, they are. It's a phenomena. :huh2:

Sorry for the hurried reply. Same as @rydfly's images. Same as @MartyNZ reported.

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Thank you everyone for your prompt replies to my questions.  I'll rest a bit easier that my orientation vs. the parts diagram isn't a terrible concern.  I will pay attention to the spline orientation with regards to the marks when I reassemble and double-check that the marks actually phase the yokes correctly.

About my challenge to separate the yoke from the final drive input spline, any thoughts on how to proceed?  

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The pinch bolts make the yoke quite tight on the spline, and there may be some slight distortion of the yoke where it touches the spline. A sharp edge can get swaged/smeared so it touches the end of a spline tooth in the recess for the pinch bolts, that will make it hard to remove. Assuming there's no rust, I'd try opening the pinch slot of the yoke with wedges (big flat bladed screwdrivers) then tapping & levering.

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Thoughts, couple of wooden wegde pieces. Easy opening a tiny bit, and more wood against final drive, shoud come of.

Cheers Tom.

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7 hours ago, activpop said:

Same as what docc? The pictures or the diagram? Mine had the female spline off of the gearbox, just like the diagram. That is the shorter piece with the grease zerk. I marked mine before I removed it. It was not lined up with the factory white marks...almost 90° off. The yokes were not on the same plane. If I put it back to the marks, they are. It's a phenomena. :huh2:

With the short/female section of the shaft forward at the gearbox, is the shaft Zerk accessible behind the safety collar?

And, perhaps more to the point, is the front uni-joint Zerk more easily accessed with this shaft orientation?

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@docc, I dont have it back together yet so can't answer that. Many things in life this year have kept me from putting the time in...covid for one, lost a whole month there.  Soon though. What baffles me is the difference in orientation of the driveshaft on different bikes. Mine was like the shop manual diagram. Why are others spun around? Don't have a clue, but mechanically it shouldn't make a difference.

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This has me wondering if the short, unshielded end of the shaft forward allows the (otherwise unexplained) easier access to the front uni-joint Zerk in some V11.

Anyone else with a shaft oriented this way?

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So, if you put the driveshaft on backwards does the bike run in reverse?

I'll let myself out the door...

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99, 01, 03, 04 all with female towards tranny.  And greasing my zerks I find not to bad, ok involves the misses handling the gun, or a buddy.

Cheers Tom.

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