Friday, December 21, 2012

More cracks for Chris

A thorough cleaning and inspection of the transmission case revealed some more cracking:


Fortunately, this is the only primary attachment bolt that actually threads into the transmission case.  The rest simply pass through and have a nut and washer on the back.

To add insult to injury, there is a piece of broken bolt imbedded in that hole...


Only another incurable gear-head can appreciate the relief that this picture represents.  I successfully drilled the center of the bolt remnant, and got it out with the handle end of a rat tail file.

We'll see how Chris does on this one...   Our plan is to install a helicoil after the weld repair, in hopes of preventing an instant replay.

Case Repair - Magic!

A close inspection of my engine cases caused great dismay, when I saw that there were small cracks forming on one case half, near one of the front engine mount bolts:





There  is actually a companion crack underneath thats not visible in this photo...







Fuzzy at Classic Thunder recommended Chris Tveter (a.k.a "Tweeter") at Extreme Adrenalin to do the repair...

This is what it looks like now:



Nice work, Chris!! 

Generator drive - driving me batty

One thing that I knew was completely worn out, when I bought the Chief, was the generator drive.  A generator drive sprocket inside the primary engages with the primary chain.  The shaft for said sprocket passes through a bushing in the inner primary cover, and a pulley on the outside connects to a v-belt, which drives the generator..

The generator drive sprocket shaft is supported on both ends by brass bushings. They were so worn that the inner bushing had a clearance of about 3/32" instead of the .002" it should have...  The shaft was heavily scored, and the inner primary was wallowed out to the point where the bushing fell out upon disassembly.  Repairing all this was pretty involved...

Step one:  Order a reproduction inner primary and inner and outer bushings.

Step two: press in the bushings.  But wait...  The outer bushing, which is supposed to be a light press fit in the primary cover, goes in by hand...  not acceptable!

Step three:  Make a new bushing with an oversize outside diameter!  Atlas to the rescue!




Checking the bushing alignment and clearances with the new shaft:







Almost there.  A gentle line-hone and I think we're back in business...






 Step four: drill out the rivets holding the old sprocket to the shaft, transfer the sprocket, and re-rivet...

Step five: turn down the rivet heads you just painstakingly peened, until they are flush to the shaft shoulder, because the rivets are underneath a thrust washer (?)  Who thought this up?  I'm starting to have Sprite flashbacks...







Do you ever have the feeling that your hobby involves a certain amount of occasional mental illness?  I could have been golfing or somehting normal!







Oh yeah, one final OCD detail...  I added a modern rubber seal to the inner primary, to prevent the ever-present oil leak from behind the generator pulley.