TAV driven pulley wobble?

[EVOL Tweety Bird]

Installed a TAV from OldMiniBikes on my Coleman CT200U, and noticed something odd with it.
Spun the driven pulley and it wobbles like a drunken sailor.

Took the whole TAV off and stuck it in a vice, Removed the pulley and spun the shaft. Nothing there, runs true.
Okay, reinstall the pulley, minus the key, and did not tighten the retaining nut. Spin it and it also spins nice.

Install the key, snug the nut hand tight and still runs true when spun.

Zap the nut on with the impact and whoa baby, it's a wobbling fool. Back off the nut and it's running true again.

What the heck is going on?

 

[CarPlayLB]

It may be the impact that is causing this issue. That nut needs to be snug, but not zapped with an impact! If you torque it down too far, you could compromise the snap ring at the back of the shaft. Snug it with a wrench and then check it

 

[Raskin]

Also you might ruin the bearing if not careful.. I'd check it..

 

[EVOL Tweety Bird]

10/4 I went ahead and loctited the nut on and hand tightened it. The nylock nut that comes with it doesn't thread on far enough for the nylon to engage the threads on the shaft. Kinda silly to use this type nut when the shaft isn't long enough so the nut can do it's job.

Thanks for the tips!

 

[MJL]

I ground a bit off the back of the nut to help the nylon engage more. Just made sure to cool it often in water so I didn't cook the plastic. Hold the brake and tighten with a hand wrench. I think I saw 12 ft lbs somewhere but not sure.

 

[EVOL Tweety Bird]

yeah I guess my bad was thinking the nut had to go on the shaft far enough to engage the lock portion. If the loctite doesn't hold I'll go the grind down the nut route.

Hmm, just thought of something. The washer is really thick under the nut, maybe a thinner one would allow the nut to make it to the nylon portion of the nut.