Anyone Replaced their front pulley (sprocket) using the old bolt? Pro's & Con's??

[rjinaz86323]

Has anyone replaced this using the original bolt. I know BRP recommends using a new bolt, but any problem re-using the bolt? Thx

[T.P.]

What is bolt stretch?
As you tighten a bolt, it will stretch and generate a clamp load. The key to proper tightening of a fastener is to torque it until just slightly less than the bolt's elastic limit. A bolt will stretch slightly as it is tightened. If you tighten the bolt too much, it will stretch beyond its elastic limit.

T.P.

[rjinaz86323]

I understand bolt stretch. That is why I asked this question.

[K80Shooter]

It's only going to be on there for a short period of time. Once the "Final" repair is done which more than likely be yet another pully then new one would be installed then.

Install it and go on your trip and enjoy it. If it's bothering you, it can then be replaced when you get back.

As a side note, I've rebuilt numerous Cummins and Detroit diesel engines in my life. We always inspected and reused most all of the bolts from head bolts to crankshaft bolts.
These engines were then ran another 150,000+ miles with no bolt problems.

Granted this was several years ago and I'm sure some things have changed since then.

[PMK]

In accordance with the current recall, after completing the dimensional inspection for spline wear, the original bolt is reinstalled and torqued. So even Can Am is now reusing the original bolt rather than replacing it.

FWIW, and I verified this previously, the current torque spec is a standard non stretch torque value for a bolt that diameter and pitch. In situations such as that, the bolt is not torqued to yield so can be considered for reuse many times. These bolts do have a preapplied thread locking compound and there is degradation of that feature. On our Spyder, I accomplished drilling the bolt head, and lockwire the bolt after it is torqued. Doing this I have no concern of degraded thread lock, and also have no concern of what the run down torque is and how it may contend with proper bolt torque. A quality torque wrench, ideally that is calibrated, should be utilized to reduce the possibility of over stressing the gearbox output shaft, which could result in failure of the shaft.

[KX5062]

I pulled mine on my new 2020 to check and see if the spine came with lube (it did, but not much), relubricated the spine shaft, cleaned the bolt and reinstalled using loctite. No worries. Some people have posted in the past that it was a one-time only part. Without being a material engineer, only a mechanic, it does not appear to be and is just a standard high strength bolt. (IIRC, rated at 10.9)

[Jdr00ejr]

FWIW, as PMK mentioned - BRP is removing the bolt for inspection and reusing the same bolt. From what I've read/heard - they aren't even using new locktite. I had a White Pulley on the shelf as I work on Spyders as a hobby gig - and I wanted to keep one I could carry with me on trips as well. I just used it on the wife's Spyder who had serious red dust (shattered my foot in April and haven't inspected it like I normally do so didn't catch it early). Using my shelf white pulley and bolt - I ordered another one not holding my breath. Much to my surprise, after a short backorder I did receive the white pulley - just not the bolt yet - which is still on backorder. If I need the pulley before receiving the bolt - I'll be cleaning the old bolt and reusing it for sure.

[azprince]

I ordered a standard pully and my order was cancelled in 4 days. I'd love to get my hands on a new pully. someone mentioned a new PN but i can"t find the post. Any help would be appreciated.

[Jdr00ejr]

I ordered a standard pully and my order was cancelled in 4 days. I'd love to get my hands on a new pully. someone mentioned a new PN but i can"t find the post. Any help would be appreciated.

I ordered from PartsPitStop...
White Sprocket (Pulley) "705503239"
Flanged Hex Screw M12x65 Scotch Grip "250000250"
Washer "705503239"

Both the Spocket and the screw/bolt were back ordered but the Sprocket came in and they shipped me the sprocket and washer. Waiting on screw/bolt.

[T.P.]

Washer "705503239"

with the flanged bolt, there is no washer used on my 2017 F3T ?

T.P.

[Jdr00ejr]

with the flanged bolt, there is no washer used on my 2017 F3T ?

T.P.

Not all years used the combo bolt. Some used a bolt and separate washer. Mine is a 2015 F3S. I'm sure they are interchangeable - but I ordered based on the fiche for my bike.

[PMK]

Not all years used the combo bolt. Some used a bolt and separate washer. Mine is a 2015 F3S. I'm sure they are interchangeable - but I ordered based on the fiche for my bike.

The bolt / washer design was upgraded to the flanged bolt style years ago. I was under the impression the original style setup was NLA. The new design supposedly has greater strength against distortion of the flange vs the washer, and is less susceptible of dropping tension over time.
Ironically, this was kind of a very early hope to eliminate spline wear on the pulley. Unfortunately it did not accomplish that as planned.
Your Spyder, obviously to assemble as you desire. This information may help others and lessen misinformation that circulates. Good luck with it.

[Jdr00ejr]

The bolt / washer design was upgraded to the flanged bolt style years ago. I was under the impression the original style setup was NLA. The new design supposedly has greater strength against distortion of the flange vs the washer, and is less susceptible of dropping tension over time.
Ironically, this was kind of a very early hope to eliminate spline wear on the pulley. Unfortunately it did not accomplish that as planned.
Your Spyder, obviously to assemble as you desire. This information may help others and lessen misinformation that circulates. Good luck with it.

Thanks for the added clarity for others PMK. I will say last time I ordered (a year ago maybe - white pulley) I used the old part numbers on the 15 fiche and did receive the bolt/washer separately as ordered. So wasn't NLA at that point. Parts Pit Stop told me the part was on Backorder and shipped the washer separately as stated above this time - so assuming still not NLA? I mark my bolt/washer/sprockets when I install them - so I can monitor any movement. I can see where the new design would be considered an upgrade - but have not had any noticeable increase in issues with the 2 piece design either.

I kept a single piece bolt when I replaced my last pulley that I can clean up and reuse should I need it before the new one arrives.

[pauly1]

I replaced a failed sprocket on our 2018 F3T using a new bolt. The threads in the output shaft were cleaned with brake cleaner and blown dry. When installing the new bolt, I measured about 30-40 inch-lbs of resistance. Arguably, it adds some lubricity to the threads but the additional torque to overcome the yellow thread locker on the bolt is negligible on 110 ft-lbs to set the new sprocket. On our other 2 F3's, I re-used both the sprocket and bolt, using Loctite 242(?) Blue compound.

If the bolt were tightened to yield but not fracture, it would like strain/work harden. The elastic constant remains the same but the subsequent yield point would be higher, due to higher hardness, assuming that sufficient neckdown of the bolt cross section has not occurred. The root of the thread would be the smallest cross sectional area, and also a stress concentration feature.

It wouldn't make sense to torque the bolt to yield as the likely breakage area would be at the transition of the thread to the major bolt diameter. The thread in the hole is being more evenly stressed due to thread engagement, with the transition area from thread to major bolt diameter would be outside the shaft threads. That's why threaded fasteners will break between the exposed area between the female thread and the underside of the bolt head.