Previously (https://mearcat.blogspot.com.au/2011/07/alternator-mount.html), I have made the alternator mount bracket and a tensioner bracket but the bolt arrangement I used through the tensioner pulley meant that it was not yet aligned properly with the alternator pulley. The bolt and spacer was a bit of a hack job at the time, grinding the M16 bolt by hand down to approximately the 15mm diameter required for the pulley bearing ID, and a spacer that was just two standard washers tack welded together.
This time, I used the lathe to machine down another M16 bolt to the correct diameter and length. I also machined a custom spacer to correct the lateral position of the the flat tensioner pulley in line with the alternator pulley. The nut was also turned down in width due to the small clearance between the pulley and plastic timing belt cover. I was not concerned with machining away approximately half of the M16 thread depth as the bolt is only used to hold the pulley in place and doesn't need the strength of the full thread depth.
The original M16 bolt / nut and after turning them down for the tensioner pulley (custom spacer on the left) :
The tensioner pulley with the custom bolt & spacer, aligned with the alternator pulley :
When I first made the bracket for the alternator, I clamped some flat steel bar vertically to the crankshaft pulley that ran upward from the crank pulley and stopped just below where the alternator pulley was going to be. This allowed me to do an quick alignment by eye, but there was still a possibility that the alternator pulley angle was not the same as the crankshaft pulley which would cause premature belt wear. I have since purchased a digital angle gauge (accurate to 0.1 degrees) and I measured the angle of both crankshaft and alternator pulleys. Amazingly, I had managed to align them near perfectly!
This time, I used the lathe to machine down another M16 bolt to the correct diameter and length. I also machined a custom spacer to correct the lateral position of the the flat tensioner pulley in line with the alternator pulley. The nut was also turned down in width due to the small clearance between the pulley and plastic timing belt cover. I was not concerned with machining away approximately half of the M16 thread depth as the bolt is only used to hold the pulley in place and doesn't need the strength of the full thread depth.
The original M16 bolt / nut and after turning them down for the tensioner pulley (custom spacer on the left) :
The tensioner pulley with the custom bolt & spacer, aligned with the alternator pulley :
When I first made the bracket for the alternator, I clamped some flat steel bar vertically to the crankshaft pulley that ran upward from the crank pulley and stopped just below where the alternator pulley was going to be. This allowed me to do an quick alignment by eye, but there was still a possibility that the alternator pulley angle was not the same as the crankshaft pulley which would cause premature belt wear. I have since purchased a digital angle gauge (accurate to 0.1 degrees) and I measured the angle of both crankshaft and alternator pulleys. Amazingly, I had managed to align them near perfectly!
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