Tips for lining up press fit sprocket on a crank???

[berettafan]

Not 911 related but am having a terrible time lining up a press fit sprocket on the crank shaft of my R25. The sprocket has to be pressed on and actually goes quite a bit of the way on its own when heated with a torch. The real trick is that it has a notch that has to be lined up with one of those quarter circle shaped insert thingys (forget the tecnhical term) and i am making a total mess out of the crank and sprocket by missing a little bit each time i try (some nasty scratching and gouging).

Is there a trick to this???

[lucittm]

I have had the same problem before. I think the factory does this before the crank goes in. I would use some crocus cloth or fine sandpaper to create a slight taper that allows you to get the pulley on far enough for the woodruff key to engage with the broached keyway. Then hammer (with a wooden block) it all the way home. Heat on the pulley helps, and if you could cool the shaft that would help too. Hairspray makes a good lubricant and then it locks the final assembly, since it is basically glue.

Mark

[cgarr]

You have to line it up with the Woodruff Key but cannot get it to that point without pressing it on? Is there anyway to chill the crank and heat the sprocket? I have done this on Porsche layshafts with new gears, kind of the same thing, you only get one shot at it that's the problem, it has to be lined up and ready to go. Like Mark said, get everything smooth and polished ready to go, chill the crank, heat the sprocket and use some lite oil and try to get it to the key quickly then press it home.