I've been staring at my F135 engine harmonic balancer since I got it, wondering why it appears to wobble a bit. Took it by my mechanic/friend, who grabbed it, and said that it appeared to be tightly in place, but pointed out that it had an abnormally small pulley groove in it, and an abnormally small fan belt. Which, he observed, went with the GM alternator that someone had installed, using a variety of broken brackets. Well, I'm wondering how someone got a smaller than normal pulley onto the harmonic balancer, and I'm thinking that maybe I need a replacement, especially since my plan is to put a Landcruiser alternator on there with properly fitting brackets. The whole shebang: alternator pulley, water pump pulley, and crankshaft pulley, does not line up entirely correctly, so I can only imagine that the smaller than normal fan belt is stressed by this and it is only a matter of time before something breaks. So, I was talking with Steve C. the Poser this morning about his stash, and what might be in it, and we talked about pressed on harmonic balancers and handcrank nuts and so forth, and he suggested I look at my older engine manuals to make sure we are all talking about the proper replacement. And so, I did. I first looked at the 62 manual. Then the 64. And I saw this. What the hell, I'm thinking. Something's missing here. There's a pulley, but no Harmonic Balancer!