Driveshaft toast, my fix

[tsiceman]

17 winder, 6300 miles.

Doing spring (summer) maintenance and found a bunch of slop in driveshaft and bearing. Ordered new shaft and bearing.
I was planning on having shaft repaired for a spare, but it is also wore pretty bad at outer brake rotor snap ring groove, which made it tough getting rotor off. Ended up using a puller to get if off.
So my fix was to grind a groove in bearing and and a set screw threaded into shaft. Note, set screw is ground to fit the groove similar to a keyway.

 

[Turboflash]

I like the idea but what are you doing to keep the set screw tight? Lots of vibration, reversing load, heat cycles, etc. Many have tried putting 2 set screws through the shaft wall from inside and trying to lock inner race but it has not proven to hold up over time. Set screws work loose and fall out. Shaft wall is pretty thin so there isn't allot of threads engaged. Even red loctite has not prevented them from coming loose. Maybe a tack weld is only thing that might hold?

 

[tsiceman]

Set screw cannot turn since it is captured by slot in bearing.

 

[Chris-RX-1]

Good fix!

 

[sidewinder 2018]

View attachment 155844 View attachment 155845 View attachment 155846 View attachment 155847 View attachment 155848 17 winder, 6300 miles.
Doing spring (summer) maintenance and found a bunch of slop in driveshaft and bearing. Ordered new shaft and bearing.
I was planning on having shaft repaired for a spare, but it is also wore pretty bad at outer brake rotor snap ring groove, which made it tough getting rotor off. Ended up using a puller to get if off.
So my fix was to grind a groove in bearing and and a set screw threaded into shaft. Note, set screw is ground to fit the groove similar to a keyway.
View attachment 155839 View attachment 155840 View attachment 155839 View attachment 155840 View attachment 155839 View attachment 155840 View attachment 155841 View attachment 155842 View attachment 155843

Great post That is the exact repair that my dealer is doing this fall.just replacing the shaft is not solving this issue.Great pics. Don’t forget chain case upgrades at the same time ‍Franks in Essex Juntion,Vt will refurbish your lower shaft with a anti rotation pin,and send you back a upgraded notched bearing Approximately $200

 

[swampcat]

Set screw cannot turn since it is captured by slot in bearing.

Good thinking. Next teardown will tell if it worked.

 

[STAIN]

seems like a good fix. Do you have a picture of the screw used before installation? I could also seeing putting a small bead of weld on the shaft to line up with the slot in the bearing, them maybe filing to fit.

 

[Turboflash]

Set screw cannot turn since it is captured by slot in bearing.

Yes, but don't you think eventually it will become loose in threaded side and wear/fret out the threads enough for it to fall out? Maybe not.

 

[tsiceman]

No pics of screw, sorry! Mine is a set screw that I hand ground the end to fit slot in bearing.
I made slot in bearing with a 1/8" diamond bit on my roto zip, definitely need water to cool bit.
Turn set screw in or out 1/2 turn with allen wrenches to adjust height, possibly need to regrind/ file some for premium fit! I got lucky and fit great first try!
I used 1/4-20 set screw, but I would recommend using a finer thread for easier ht adjustment

 

[tsiceman]

I don't think that will happen, but I guess that is possible, but set screw fit pretty snug in there.
Driveshaft is approximately 3/16 to 1/4" thick at bearing area

 

[STAIN]

I dont see how it could fall out. Where would it go? Did you tap the hole completely through the shaft?

 

[tsiceman]

I dont see how it could fall out. Where would it go? Did you tap the hole completely through the shaft?

Hole is tapped thru one side of shaft.
It is possible threads could get egged out, but there is not much force on the set screw as long as bearing is good.

 

[kinger]

Good repair, I updated the master list of issues thread stickied at the top. Thanks @tsiceman !!

 

[twyztid]

Would a welded & machined raised ridge on the shaft with a groove machined into the bearing also work? I am thinking that if a machine shop had to repair a driveshaft already, they could also add the ridge to the shaft and machine the groove into the bearing.

Either way, I think the BOP driveshaft saver is still a better bet since it locks the driveshaft to the complete ID of the bearing.

 

[FrozenTows4]

Will be interesting to see how this key holds up after a season of riding.

Think about how many times you're on & off the throttle each ride.
Each on throttle the bearing inner race hits one side of the key. Each off throttle it hits the other side.
The key is not so tight that the bearing inner race can not rotate a little. Otherwise it would be impossible to install the bearing.
Over time, that little will be come more. Eventually shearing the key and allowing the bearing inner race to rotate, on the shaft, once again.

Or, the key fragment will wedge between the inner race and shaft.
Good new is now the inner race should really be locked to the shaft.
Bad news is bearing removal will be a real treat.
Hopefully that's not until the 10,000 mile service.

I still feel locking the bearing, with the shaft expander, is the only real solution for our current configuration.

I have yet to see an application where the key is the only anti rotation devise. Typically a key is for positioning only.
Flywheels, harmonic balancer, cam sprocket, crank sprocket, etc.
The key does not hold these. The bolt torqued to spec does.