Broken output shaft - Final Drive Belt Tension involvement?? Sept '23 BEFORE RECALL

[MeudtPG]

Thanks in advance for input.
2018 RTL. :spyder:
1) After replacing recall drive sprocket should the final belt tension be readjusted or at least checked?
2) What damage can occur if the final drive belt tension is too tight?
A) Could output needle bearing be destroyed causing output shaft to break?
B) Would belt break before doing major damage?

 

[BLUEKNIGHT911]

Thanks in advance for input.
2018 RTL. :spyder:
1) After replacing recall drive sprocket should the final belt tension be readjusted or at least checked?
2) What damage can occur if the final drive belt tension is too tight?
A) Could output needle bearing be destroyed causing output shaft to break?
B) Would belt break before doing major damage?

If the work was done by a dealer ..... they will/should check the tension ..... However, if they do, they will set it to BRP SPECS .... and IMHO & most others here - BRP Spec tension is way too high ..... I use a KritKit gauge and have mine set at 160 lbs. with the wheels on the ground .... good luck ....Mike :thumbup:

 

[Navydad]

No reason to loosen the rear wheel in order to install front pulley. My dealer didn't. Rear wheel off ground and rotate the wheel backwards while pulling the belt off. Install front pulley and reverse the process. Nothing changed as far as my belt tension or alignment.

 

[BajaRon]

Thanks in advance for input.
2018 RTL. :spyder:
1) After replacing recall drive sprocket should the final belt tension be readjusted or at least checked?
2) What damage can occur if the final drive belt tension is too tight?
A) Could output needle bearing be destroyed causing output shaft to break?
B) Would belt break before doing major damage?

A too tight belt can destroy bearings at either or both ends. However, the 998 models run a lower tension and the 1330 runs a higher tension. They beefed up the 1330 output shaft bearings as well as the rear wheel bearings to accommodate the higher belt tension. I have been told that the working tension on the drive belt can be as high as 600 lbs. So the belt is way over engineered.

 

[MeudtPG]

A too tight belt can destroy bearings at either or both ends. However, the 998 models run a lower tension and the 1330 runs a higher tension. They beefed up the 1330 output shaft bearings as well as the rear wheel bearings to accommodate the higher belt tension. I have been told that the working tension on the drive belt can be as high as 600 lbs. So the belt is way over engineered.

Anyone had this happen from overtightening belt before?

 

[MeudtPG]

No reason to loosen the rear wheel in order to install front pulley. My dealer didn't. Rear wheel off ground and rotate the wheel backwards while pulling the belt off. Install front pulley and reverse the process. Nothing changed as far as my belt tension or alignment.

Question: Did the dealer check the belt tension after installing the new recall sprocket?
How do we know both the new sprocket and old sprocket didn't change the belt tension?

 

[BajaRon]

Anyone had this happen from overtightening belt before? View attachment 204995

Too tight belt tension may have contributed to this. But I would think the bearing would give out before the shaft, unless there was some flaw in the shaft to begin with.

 

[MeudtPG]

If the bearing went out first causing the shaft to break possibility?

 

[BajaRon]

If the bearing went out first causing the shaft to break possibility?

Possible, I suppose. It's hard to tell but it appears that some of the rollers are missing from the bearing. Bearings usually give some warning that they are failing. It would take quite a bit to break that shaft. Does the bearing turn at all now?

 

[BLUEKNIGHT911]

Anyone had this happen from overtightening belt before? View attachment 204995

Is that from / on a Spyder ????? ..... Mike :thumbup:

 

[MeudtPG]

Is that from / on a Spyder ????? ..... Mike :thumbup:

Yes Mike! A 2018 RTL with 14,541 total miles on Spyder. Had the sprocket recall done at dealer 3172 miles ago and nothing adjusted for belt tension since 6923 miles for a new rear VREDESTEIN Quatrac 5 - 205/60R15.
We are currently trying to find the reason this failed but suspect maybe belt tension as the culprit after recall sprocket installed without checking tension? Whatever caused this very serious failure needs to be discovered so any thoughts are welcome.

 

[Peter Aawen]

If the bearing went out first causing the shaft to break possibility?

Possible, I suppose. It's hard to tell but it appears that some of the rollers are missing from the bearing. Bearings usually give some warning that they are failing. It would take quite a bit to break that shaft. Does the bearing turn at all now?

Yes Mike! A 2018 RTL with 14,541 total miles on Spyder. Had the sprocket recall done at dealer 3172 miles ago and nothing adjusted for belt tension since 6923 miles for a new rear VREDESTEIN Quatrac 5 - 205/60R15.
We are currently trying to find the reason this failed but suspect maybe belt tension as the culprit after recall sprocket installed without checking tension? Whatever caused this very serious failure needs to be discovered so any thoughts are welcome.

View attachment 204996 View attachment 204997

The belt tension might've been the final trigger, and it looks like the bearing wasn't really happy either, but going by those pics, I'd hazard a guess that the shaft wasn't all that great to start with and that failure was bound to happen eventually anyway, with or without any other contributions!! :yikes:

 

[pegasus1300]

That bearing isn't any good. I don't know if the failed bearing took out the shaft (Though that is what I suspect) or the failed shaft took out the bearing. That shaft should go to a metallurgical lab to determine the failure cause. It looks like the shaft sheared off because the failed bearing would no longer let it spin at speed.

 

[Isopedella]

Thanks in advance for input.
2018 RTL. :spyder:
1) After replacing recall drive sprocket should the final belt tension be readjusted or at least checked?
2) What damage can occur if the final drive belt tension is too tight?
A) Could output needle bearing be destroyed causing output shaft to break?
B) Would belt break before doing major damage?

Talk about a " Loaded Question" Think a more straight up 1st post in this thread would be more ........ well take ya pick.



Fire for effect.

 

[Mikey]

So are you doing the work and trying to figure out how and what to point the finger at? Is BRP involved? They should be! I would say that this shaft was brittle for whatever reason, bad material, heat, and with that you add a lot of side tension and some torque, then you get a break. The hard part is that you have to know how hard that shaft was supposed to be, and that numbers going to hard to get if BRP don't want to play nice, then it would have to go a lab to be tested!! My hopes and prayers are that BRP will help you out on this one, because that really sucks to see! Good Luck!!

 

[SkipH]

I'm wondering what the case bearing looks like?
I can see where a grove was cut outside of the bearing and also can be seen on the shaft. if that was a sharp cut then that could have caused the shaft to shear. There has to have been some wobble in the shaft/pulley to destroy the bearing.
then again it could have been the bearing going out that caused the wobble fatiguing the shaft.

 

[kimmjoey]

The belt tension might've been the final trigger, and it looks like the bearing wasn't really happy either, but going by those pics, I'd hazard a guess that the shaft wasn't all that great to start with and that failure was bound to happen eventually anyway, with or without any other contributions!! :yikes:

I am not a metallurgist nor engineer I have many friends that are including one that did QC on fan blades on aircraft. He explained that there is specific equipment to check the metal integrity. Casting metals is a science and all sorts of things can go wrong. On the surface we can all look and say, well the bearing caused the shaft to to shear but more evidence must be looked at the dogs on the gears there would be some sort of evidence of stress there as well I suppose, not just from metal being introduced and being meshed.... or some impurities present during casting... :yikes: however I did stay at a Holiday Inn express last night....... :roflblack:

Not sure where our 17 falls in the production date... does the numbers in the vin supply that information? We plan on keeping our 17 RT LT couldn't pry that bike from my wife's hands so we'll get it fixed and keep on trucking...

 

[racoon]

however I did stay at a Holiday Inn express last night....... :roflblack:

Did you take advantage of the free breakfast?

:bbq:

 

[TheMariner]

I don't think something like an Output Shaft would be cast. It's more likely machined from hot-rolled bar or from a forged billet.

Here's my 2c worth...

In my opinion the failure is because of 1 of 3 possible reasons:

1). Failure of or no material QA performed before being machined. The hot-rolled or forged billet had a processing fault in it that wasn't found before the part was machined, hardened, & ground. This is unlikely because every shaft is breaking in the same way. Rolling or forging faults are usually more random.
2). Poor material choice and/or heat treatment. The material isn't strong enough for the job at hand in the first place or the heat treatment is too savage leading to brittleness.
3). Design. Machined-in stress raisers that play havoc with fatigue resistance that'll eventually lead to fatigue failure. Rotational bending is a high-risk condition that is bad for fatigue resistance. Throw in shock loading & the occasional reverse bending & it's a nightmare for Designers.

The pics of the broken ends all look the same... 3/4 of the annular breaks are a dull, grey, flat-ish surface & the remainder is a shiny jagged surface. To me, that says fatigue failure. The dull grey areas have been cracked for a while and fretting together (hence the kinda smooth surface) but there was enough solid shaft left to still hold it together. When the cracked area gets too big, the remaining solid shaft isn't strong enough to keep it together, so it breaks suddenly. This gives a shiny, jagged break.

What allowed the shaft to fatigue is the next question. If it's a design error, then we'll all be in trouble eventually... not just some of us. Because it's a bit more random, I think it's either a physical machining error that should have been identified in post-machining QA; it's a heat treatment problem; or a combination of both.

The interesting thing is that BRP are able to narrow it down to individual Spyders for the recall (thankfully, not mine) which, to me, indicates they know the actual shaft UIN (Unique Identifying Number) involved. UIN's are not usually applied before machining & heat treatment.

I may be wrong :dontknow:

 

[racoon]

In my opinion the failure is because of 1 of 3 possible reasons:
. . .
I may be wrong :dontknow:

Or maybe shafts that were made on Tuesdays, after 3-day Holiday weekends?