Avoiding the Dreaded Crank Spline Strip

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Wheelman-111
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Avoiding the Dreaded Crank Spline Strip

Post by Wheelman-111 »

Greetings:

The Dreaded Spline Strip is easier to achieve than you'd think. The issue doesn't arise from Operation - Sprees and Aeros aren't exactly Torque Monsters - but from Assembly.

The belt is the problem for the uninitiated. If nothing is done to keep it away from the center, then the outer pulley sheave's splines can't reach those of the crankshaft to begin engagement. The unwary "Mechanic" then proceeds to thread on and wail on the pulley nut until it "feels tight", but what has happened is that the sheave splines have crushed and mangled those on the crankshaft about halfway down. The first ride finishes off the rest as the pulley now goes loose and awobble, grinding away what was left of the splines on the crank. The Aero-SE/05 crankshaft in particular has a very short spline section that's easy to get wrong.

Fortunately all that is necessary to keep the belt away from center is to spread the rear pulleys a little and pull the belt forward, forming a longer and larger-diameter front loop of belt. Now the outer sheave can be fully seated onto its crank splines by hand, BEFORE the nut is tightened down.
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
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