zeeboost Posted August 31, 2004 Share Posted August 31, 2004 Okay, here’s my dilemma. I bought the ’95 Maxima 125 alternator, and after searching through the archives and gathering up all of the information I could (mostly from Nismo280zEd’s write-ups because they seemed to be the most informative), I was positive the pulley swap would be pretty easy. So, I bought the alternator and found out that the Maxima shaft is much shorter than I expected. I took the alternators to three alternator shops with all of them giving me the same answer – “It can’t be done.” I’m just trying to figure out why this one is different than anyone else’s. Here, you can see how much shaft I have to work with from the Maxima alternator. The V-pulley I was trying to use came from an early ’77 280z. Here you can see what the V-pulley looks like on the Maxima alternator without any kind of spacer (washers/bearings/bushings/etc.) behind it. To me, it seems like my only option would be to take the V-pulley (right) to the machine shop and have him machine down (just kind of bore out the middle, but not bore it all the way through) the inside of it in order to match the Maxima pulley’s (left) specs. I haven’t heard anybody else resolving this problem by taking their pulley to the machine shop, so if you can see what I’m doing wrong or what I need to do to fix this, please let me know. I’m going to be moving to another city this weekend and I’d rather drive my car than try to find somebody who can tow it, and as stated above, I searched thoroughly through the archives without being able to find the information I needed. Thanks for the help. Quote Link to comment Share on other sites More sharing options...
datsunlover Posted September 1, 2004 Share Posted September 1, 2004 I'm puzzled as to how thw Maxima Alt pulley is held on the shaft (from spining).. there's no keyway in there (as far as I can see..) so is it just a nut and lock washer? or is there a set screw in there? Also, the maxima pully looks to have a smaller inside diameter than the older Z pulley.. (maybe just the pic though?) hmm.. maybe the shaft from the Z alternator is interchangable with the Maxima Alt? From those pics thats all I could really think of.. As for boring out some of the pully, it could be done.. but that keyway in the Z pulley is gona be hell on the cutting tool..(intermitent cut.. 'bang' 'bang' ect) it might get expensive! Quote Link to comment Share on other sites More sharing options...
Guest 2slo4u Posted September 1, 2004 Share Posted September 1, 2004 I tried the same alternator on one of my previous zx's. I searched all around town at auto parts stores because some of them had pulleys left over from used alternators, etc. I finally found one that would work by putting a small spacer behind it and putting loctite on the threads and using an impact to tighten it. The auto parts guy said that using the impact on the nut was all that was needed to keep it tight, but I wanted the extra safety of the loctite. After installing the alternator, I noticed the offset of the pulley to the engine's pulleys. It was way off, about half an inch too far back I think. After driving the car about thirty miles, the brand new belt shredded into a small rubber band-like strand. I could only figure out that the offset caused this problem because there were no burrs on the pulley and the v of the alternater pulley had the correct angle for the belt. Impacting the pulley worked for the pulley I found but the offset might cause you a problem. Just don't go on a long trip before making sure your belt isn't being destroyed. By the way, are you running high power stereo equipment? Just wondering why the maxima 125 and not the 280zx turbo 70 amp? Brian 81zxturbo 95slobaru Quote Link to comment Share on other sites More sharing options...
zeeboost Posted September 3, 2004 Author Share Posted September 3, 2004 Thanks for the replies. Yes, it is just a nut and washer holding it in, but from what I’ve worked on at the shop that’s a pretty standard setup for serpentine pulleys. Both pulleys have about the same diameter hole in the middle. What I ended up doing was just going back to one of the alternator shops to pick up a V-pulley to match the serpentine pulley as close as I could. I found one that was almost perfect, so I took it to the machine shop and hopefully tomorrow it should be ready. There wasn’t a keyway on it so it should’ve been easier on the equipment. I have custom brackets to mount the alternator, so if the pulley isn’t lined up I can either shim it down, bend it, or just create another one. And yes, I feel that I do need a large alternator because: A) I have dual electric fans that pull a TON of current (my cigarette lighter only gets about 11 volts when the car is between 800 – 1600 rpms. I will be installing an amp and subs in the future – not anything huge, just a pair of 10”s and perhaps a 400W amp. I don’t feel like watching my headlines dim to the beat of the music at night. C) I run a lot of electric accessories. I think the 90 amp alternator would’ve been easier (especially on the wallet), but I wanted the peace of mind. I’ll let you know how it goes. Quote Link to comment Share on other sites More sharing options...
zcarnut Posted September 3, 2004 Share Posted September 3, 2004 I've done two of the Maxima alternator conversions and all I had to do was use a spacer under an early V-pulley to position it correctly. Yes, the Maxima pulley is smaller in diameter. That's how you can get more current out of an alternator at idle speeds. It's just more wear on the alternator bearings and bushes. BTW, alternators can spin at over 18,000 rpm. Quote Link to comment Share on other sites More sharing options...
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