Drive Spline Failure

[s1120]

  This is all interesting.....My point of view is that if special lube is needed then perhaps the engineering and or material is not all it can be.. My viewpoint is from extensive 4x4 experience. Driveshaft splines do wear out.. they slide in and out constantly in response to suspension travel and many designs are more or less exposed to the environment..But most do last 100,000 miles in normal service ,some much longer..All of then are lubed by tranny lube or by grease ...None run dry to my knowledge...
 What do other shaft drive bikes have? Are they a problem...Seems to me from of these shaft problems or the maintenance of pulling the shaft are more of a nuisance than the use of an O ring chain...

The BMW K bikes have a REAL bad issue with splines... that being said, I rode Suzuki GS G shaft bikes for years and never had the shaft apart, or heard of anyone having issues... 

[guzzisteve]

 How did all the Guzzi's w/300k mi on them(Karl had 2) or all the older riders like Ken have multiple bikes w/100's of thousand mi on them do this w/o greasing the splines?  IT's all BS brought on by BMW guys riding Guzzi's. Guzzi's are NOT BMW's or Hondas. They have a weak link engineered in the drive and that is the coupler and that is what failed. SmallBlocks have a ball shaped spline piece on both ends of the coupler because of only 1 cross on the ujoint and it's engineered to fail. The little balls & little splines will only go so long. Don't believe me? where are all the smallblocks w/all the miles--- there aren't any!

[wirespokes]

Steve - are you saying Guzzi splines should run without lube? Just trying to clarify.

I've been around airheads since 1990, so have some data on splines and lube issues.

I think the BMW guys who had spline trouble (other than the early Ks) over-lubed the splines and ran into trouble because of that. Now and then trans input splines would wear out, but think that was due to over-lubing leading to the creation of grinding paste. That sort of failure is pretty rare.

Generally, the airhead final drive splines tend to last 100K or more. I think one of the causes of early failure is wheel bearing issues causing the splines to work against each other. Another is corrosion, which as you know, is very abrasive and wears the mating surface. And yes, chain technology has improved enough over the years to now make the cost of chain vs shaft comparable. So it comes down to which you prefer rather than cost or maintenance.

The clutch splines are different since there's a sliding movement. But even in autos and heavy equipment, the splines are supposed to be lubed (even though very thinly) to prevent rust and help with the metal/metal contact rubbing forces.

Final drive splines benefit from lube to help prevent corrosion.

I've never owned a K bike, but do know the early ones had driveshaft spline issues. No idea what the problem was with them.

On the airheads, the final drive spline on the ring gear is what wears. It's an expensive repair requiring dismantling the final drive and sending off the ring gear to a place like Hansen's in Medford Or, where a new spline is welded in, or the splines are built up and re-machined. Not sure which. With the Guzzis, the male spline is in the wheel and easily replaced. Both the BMW and the Guzzi male splines wear, and from my own experience, the female side wears very slowly. I've been told it's the same with the Guzzis.

As for Guzzis going 300K without lube (are we talking driveline splines?) I'm really curious if that's true.

[guzzisteve]

That's exactly what I'm saying. The only lube I have seen from factory is on the wheel hub that goes into final drive. I worked on BMW's for years and airheads run oil in driveshaft tube. I've been riding & working on them(Guzzi's) since 76 and going to rallies since 80, working in dealerships since 88 and never heard of lubing the stuff anywhere. The ones that wear alot are from too much torque applied. I have twisted splines right off on my LM3. On enclosed BigBlocks the oil from rear drive (mostly vapor) comes out and travels up the shaft, there is a cutout in the pinion housing for this to happen. On smallblocks it's dry and only lasts so long, maybe 100K mi. years ago cause that's all they would go.
I think Swede's just wore through the hardened area.

[wirespokes]

Thanks for the explanation, Steve! So it's not that the splines aren't lubed, because they are, it's that they need no outside attention. Kind of like cars with the driveline exiting the transmission where they're lubricated.

What are your thoughts on Swede's wearing out only half the teeth? Seems that would be part of the issue.

[guzzisteve]

What you see wore is all that touches. Look at the parts, it's 2 balls w/splines in a strait coupler. I always thought it was light duty stuff, I shredded a set in 2 months on a V65TT.

[Rough Edge racing]

How did all the Guzzi's w/300k mi on them(Karl had 2) or all the older riders like Ken have multiple bikes w/100's of thousand mi on them do this w/o greasing the splines?  IT's all BS brought on by BMW guys riding Guzzi's. Guzzi's are NOT BMW's or Hondas. They have a weak link engineered in the drive and that is the coupler and that is what failed. SmallBlocks have a ball shaped spline piece on both ends of the coupler because of only 1 cross on the ujoint and it's engineered to fail. The little balls & little splines will only go so long. Don't believe me? where are all the smallblocks w/all the miles--- there aren't any!

  Using one u joint on a drive shaft causes velocity changes as the shaft rotates, this is why auto driveshaft use two U joints, it's why the Guzzi big block uses two u joints.Two joints cancels the velocity change..A CV joint also has no  velocity changes...There a a few vintage torque tube cars/trucks using one u joint with a sliding spline submerged in oil....

   Interesting short demonstration of driveshaft U joint velocity......You can learn something by tearing out driveshafts on off road trucks....

          https://www.youtube.com/watch?v=gmV4qwLfOMY

[blackcat]

 

New parts en route.  I’ll clean them good in the future.

Cost for these parts?

[guzzisteve]

The V9 uses a single cross Ujoint on each end of the driveshaft.

Price is $121.00 for the pinion ball & sleeve, this not bad for the mileage it went.

[blackcat]

The V9 uses a single cross Ujoint on each end of the driveshaft.

Price is $121.00 for the pinion ball & sleeve, this not bad for the mileage it went.

Nope, not bad at all.

Not that it is the same but on a Ducati, how much money would be spent at a dealer for valve adjustments at the same mileage?

[Kev m]

Nope, not bad at all.

Not that it is the same but on a Ducati, how much money would be spent at a dealer for valve adjustments at the same mileage?

A conservative $500/service (valves only, not even counting timing belts) every 7500-15,000 miles depending on the model.

So what was the mileage on this, around 80k? that's 5.33-10.66 times - or $2500-5000. On the high end, nearly enough for an entire new Guzzi smallblock bike, and the low end, nearly enough for an entire used Guzzi smallblock.

[guzzisteve]

How much does top of the line o-ring chain cost?

[SmithSwede]

I am replacing all the suspect parts because I rely on this bike for daily transportion, including work and out of state trips.  I probably could have eaked out several more thousands of miles by being gentle, but it is not worth the risk of total failure. 

The output splines on the transmission and input splines on the final drive look fine.  So I’m just replacing the U-joint drive shaft, the flat sided coupler, and the mushroom headed coupler.   Total of $316.44 in parts for 86,000 miles of service.  Call that $3.68 per thousand miles. 

I run several chain drive bikes.   No matter what I do in terms of maintenance, good quality X-ring chains are always worn out after 15,000 to 18,000 miles, at least in my hands. 

Figure a good X ring chain is $85 per 18,000 miles.  Figure new front and rear sprocket every 36,000 miles at $50 a set.   Looks like running a chain would be about $6.10 per 1,000 miles. 

So over this distance, a shaft drive has saved me about $208.12 (6.10 - 3.68 X 86). 

So I’m ahead, but not by all that much.   The shaft doesn’t create an oil mess during normal operation, I don’t have to lube it constantly or worry about it in the rain.   On the other hand, the shaft system did fail me unexpectedly, and I’m not taking a Guzzi trip over the holidays as I had planned.   In contrast, chain would have given me a lot of warning of its impending death. 

Of course, I’m not figuring the expense of repairing or rebuilding the final drive.   I suspect that when you factor in the eventual cost or repairing or rebuiding the final drive unit, the savings of using a shaft drive system disappear.   

[dxhall]

I have an SP III on the lift right now for service.  At 11,000 miles the drive shaft splines don’t show appreciable wear, but the splines do show spots of corrosion. There was rust on the shaft between the splines as well, and there the shaft shows noticeable pitting.

How water gets in there, I don’t know.  The rubber boot was in good shape and tight on the flanges.  Whatever the need for lubrication on these splines, it seems to me that a spline lube is necessary to keep water (and therefore rust) out of the splines.

As a side note, I don’t think the rear drive assembly on this bike has ever been apart.  There’s old grease on all of the splines - both on the driveshaft and the wheel/hub assembly.  Looks like factory stuff to me.

[Rough Edge racing]

A conservative $500/service (valves only, not even counting timing belts) every 7500-15,000 miles depending on the model.

So what was the mileage on this, around 80k? that's 5.33-10.66 times - or $2500-5000. On the high end, nearly enough for an entire new Guzzi smallblock bike, and the low end, nearly enough for an entire used Guzzi smallblock.

 On a performance level, the V7 is not really comparable to an equal  displacement Ducati.If the Ducati owner does his own maintenance then it's maybe 500 bucks but still a lot of hours work.. .However, 80 some odd thousand miles on a 140 bucks worth of parts that the owner can replace is pretty respectable....I can't imagine any Japanese machine doing any better...
 

[Kev m]

How much does top of the line o-ring chain cost?

More on top of the valve alignments.

&

Who gives a crap? I like shafts and belts to spread out the work, set and forget for a long, long time.

There was a time when, if I had a chain, I'd be cleaning and waxing it weekly and replacing it annually, f that.

[Kev m]

On a performance level, the V7 is not really comparable to an equal  displacement Ducati.If the Ducati owner does his own maintenance then it's maybe 500 bucks but still a lot of hours work.. .However, 80 some odd thousand miles on a 140 bucks worth of parts that the owner can replace is pretty respectable....I can't imagine any Japanese machine doing any better...
 

I think we're saying the same thing...

[SmithSwede]

I’m not sure how Ducati maintenance got into the mix here, but it’s ironic because I recently bought an old 2 valve Ducati on Dusty’s recommendation for a commuter bike.  I plan to ride it a lot. 

I recently ordered cam belts which were $88 for a pair.   Supposed to replace them every 10,000 miles.  I’ll do the valve adjustments myself.   So I don’t think maintenance will be that bad. 

Guess I’ll find out soon enough. 

[Tom]

How water gets in there, I don’t know.  The rubber boot was in good shape and tight on the flanges.  Whatever the need for lubrication on these splines, it seems to me that a spline lube is necessary to keep water (and therefore rust) out of the splines.

Condensation, unless totally airtight.

[Pizza Guzzi]

Being a relatively recent Guzzi convert ( pun intended ) and having my first small block I was quite shocked to see the amount of wear in the splined coupling in the OP's pics.
However knowing the pinion splines and the transmission output shaft splines are OK and the carnage is confined to a ( relatively ) inexpensive coupling which is not a big deal to replace I'm once again sleeping soundly.
There is even a possibility that the coupling is designed to be somewhat sacrificial in nature.
Cheers and best wishes for 2019
Glenn

[jpv7]

I’m not sure how Ducati maintenance got into the mix here, but it’s ironic because I recently bought an old 2 valve Ducati on Dusty’s recommendation for a commuter bike.  I plan to ride it a lot. 

I recently ordered cam belts which were $88 for a pair.   Supposed to replace them every 10,000 miles.  I’ll do the valve adjustments myself.   So I don’t think maintenance will be that bad. 

Guess I’ll find out soon enough.

I've owned the same beast and belt changes are easy.  Do the tension properly (lots of tricks available so no special tools required...) and they will last.  You'll adjust the valves once (assuming it wasn't done properly before), and that will be it.  My 900 cost very little in terms of maintenance - and I also tracked it.  Sorry for the off-topic post

[guzzisteve]

Condensation, unless totally airtight.

And only being ridden 11K miles in 25yrs.
 
My old SP3, I sold after 2 yrs to pay some taxes. Bought it new and it had 40K mi on it w/sold AND it went another 60K mi before he traded it off on a Norge, no lube on the splines.

[John A]

So it doesn't matter, grease ,no grease. They eventually wear out. I do know lugging the engine hammers them. After thirty plus years as an aviation mechanic seeing the care that is taken to lube shaft splines, especially accessory gearbox splined shafts that are not internal to an engine , I'll lube mine at tire changes. I have grease to use up....

[SmithSwede]

Certainly agree about lugging putting a lot of stress on these components.   However, I’m not a lugger, I’m a spinner.    I run it between 4000 and 6000 rpm.   Heavy throttle for passing is at 5,000 rpm or above. 

Heck, I don’t even use engine to decelerate.   I clutch in and let the brakes do their job. 

[Andy1]

As an owner of a 2014 V7 Stone this thread is very worrying.  My current mileage on this bike is 7000 in 4 years, so will MG be honouring warranty claims if my drive fails in....oh about 2063?
I also work on aircraft and will keep lubing mine at each tyre change - and cleaning the splines out so the lube is new and fresh.  Just adding lube is not the way.

It is good to see pilots like SmithSwede doing the miles and (unfortunately) discovering what fails.  It would be interesting to know what other failures he has had and at what mileage?
I have been very happy with the build quality and mechanics of my V7, but I do probably over maintain it
AndyB
 

[John A]

Certainly agree about lugging putting a lot of stress on these components.   However, I’m not a lugger, I’m a spinner.    I run it between 4000 and 6000 rpm.   Heavy throttle for passing is at 5,000 rpm or above. 

Heck, I don’t even use engine to decelerate.   I clutch in and let the brakes do their job.

Perfect!!!