73 ironhead sprocket shaft

[ricochet]

Hello folks.  I'm checking out all dissasembled parts to rebuild this motor and recall having a hell of a time pulling the shaft extension off this sprocket shaft.  Seems there was a fit or assembly problem.  Look at the pics.  You'll see where steel is shaved or extruded off the shaft.  This is around on all splines.  Has anyone seen this before?  The mating splines in the extension have no damage.  Also I take it this extension would be part of a compensating assembly.  Is a solid sprocket better here?



ricochet

[Pynzo]

A solid sprocket will be easier to remove in the future- simple gear puller will remove it. There's a special factory tool for pulling the compensator extension off, and the factory tool for assembling the flywheel  into the left case/timken bearing installer is what is needed to reinstall the extension. I'd go with the solid sprocket, cheaper than the compensator and less weight. As long as the polished surfaces of the shaft are not damaged, the shaving inside the spline won't cause any problems. The extension was probably harder than the shaft and that is why the splines in the compensator have no marks.

[ricochet]

Thanks.  You answered my next question too about still being able to use the shaft.  I'll dress the "spare" metal burrs off and see what it looks like when I'm done.  Seeing as it a timken bearing there's no wear to that surface.  I dissasemble the crank assembly because there was considerable rod end side to side shake but all bearing surfaces look like new.  Looking at lower rod bushings tonight.

ricochet

[Pynzo]

How are the flywheel thrust washers? Any scoring? I happen to have boxes of rod bearings in all the oversizes, AMF era stuff- if you need rod rollers let me know and i'll check my stash. I don't have a parts book for any Sportys built after '67, so you'll need part numbers.

[ricochet]

Still just getting time to look at some of this.  I didn't diassemble the pinion shaft form it's wheel but removed the sprocket shaft and the left wheel to get at the rod big ends.  Both rod big ends look to have nearly any miles on what looks like a rebuild and the crankshaft has nearly any wear as well.  I did notice what I thought to be a rather rough surface in the flywheel taper but it's not destroyed.  Just looks rough and the mating sprocket shaft taper looks OK.  This seemed strage to me.

ricochet

[wreck74]

Heres some good info.
http://www.ironheadcycle.com/pages/howto4.htm

[saltcaveminer]

from the pics i would agree with you and pynzo.as long as the fit remains snug you will be fine.please consider replacing all needle bearings and check all bushings at this time.this is your opportunity to actually feel what a new 73 sportster felt like!ps they didnt vibrate as bad as some would say.as things get sloppy or loose they start to shake a bit.good luck Salty

[nibroc]

wreck--thanks for that info from ironheadcycle--I am always learning something--pingle and s&s have never let me down--lakeshore hd is decent on these old ironheads too!!!!! 

[ricochet]

That is great info to review.  Thanks.  I did take a look at the thrust washers and they do have a fair amount of scoring.  Not as much wear but scoring.  Also, they seem to measure less than .060 and I believe .062 is required on those.  Is it possible they used the earlier thrust washers or this may even be an earlier crank assembly.  It didn't come with this bike.  The pinion shaft had a ball of fur almost hard feltlike stuck way down into it's oil passage.  Maybe it was oil starved or it could have been from sitting in dirty storage.

ricochet

[Pynzo]

Oil starving will happen if anything gets stuck in the pinion passage. Replace the thrust washers, I believe it will need bronze for aluminum roller cages, and steel for steel cages. A '73 should have aluminum cages with bronze thrustwashers. The rollers are also different between aluminum and steel cages.

[ricochet]

I did further disassembly of the flywheels to check all shaft tapers and also figuring it would be best to start from scratch for allignment purposes and trueing.  All tapers look ok.  And I'm going to order a new NOS sprocket shaft.  I got a NOS sprocket and measured splines and mating grooves.  Grooves on sprocket are .250 and the splines on this shaft with the burrs is .256 to .258 depending on which spline you measure.  Seems a bit tight doesn't it?

Old thrust washers are bronze.  Will check bearing retainers.

Dick