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Deer Valley, Arizona
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1984-1986 Nissan 300ZX / Maxima Alternator swap

Click any picture to see an enlarged view.

First, go to the local parts place and buy an alternator for the 1989 - 1992 Nissan Maxima. They run anywhere from $125 to $250. Buy one that has a lifetime warrenty. Make sure it tests okay before you leave the store. I've walked out with two bad ones right out of the box. After that, I had them test the alternator before I left the store. We found 3 other bad ones this way. Now, this next part is optional. I chose to stick with the original Maxima pulley. This way, I didn't have to worry about swapping pulleys around between the alternators. In this case, you will need to get a new crank pulley and a new water pump pulley. I pulled them off an 84 turbo motor. It works perfectly. I'm pretty sure you can get a water pump pulley off any turbo or any 87+ NA. I think you'll need any 84-86 turbo crankshaft pulley. Basically, look for any that has a regular V belt for the front two and a multi-ribbed style for the rear.

Tools requires

  • regular 8 mm socket
  • regular 10 mm socket
  • regular 12 mm socket
  • deep well 12 mm socket
  • regular 14 mm socket
  • 3" extension
  • 6" extension
  • Socket Wrench
  • 10 mm wrench
  • 12 mm wrench
  • flathead screwdriver
  • pliers
  • 7/8" socket
  • torque wrench
  • car ramps or jack and jack stands
  • creeper (unless you like trying to slide around on your back on concrete)

Parts Needed

  • 1989 to 1992 Maxima alternator.
  • Crankshaft pulley
  • Waterpump pulley
  • Fan Belt 14 mm x 935 mm Micro-V

Time Required

  • approximately 2 hours

Steps

  1. Put the front of the car up on ramps or jack stands.
  2. Disconnect the battery.
  3. Loosen and remove all the belts.
    1. Power Steering belt - Loosen the adjustment nut (12mm), then loosen the staying bolt (12mm).
    2. A/C belt - Loosen the top bolt (12mm), then loosen the nut (14mm) holding the pulley in place.
    3. Alternator and Fan belt - Loosen the adjustment nut (12mm), then loosen the staying bolt (12mm).
  4. Remove the fan, water pump pulley and the shroud. To ease removal, remove both fan and shroud at the same time.
    1. Remove the upper fan shroud support by removing the 10 mm nuts and bolts.
    2. Remove the lower fan shroud supports by removing the three clips.
    3. Remove the fan and water pump pulley by removing the 4 nuts (10mm).
    You may now remove both the fan and shroud together.
  5. Remove the alternator by removing the 3 bolts (12mm) holdin it in place. Remove the bolt holding the adjustment arm to it. Remove the bolt holding the alternator to the rear of the bracket. Remove the bolt holding the alternator to the front of the bracket.
  6. Move the alternator to an easier to access location. You can either disconnect the alternator now, or you can disconnect the alternator sub harness at the two connectors and remove it all as one piece.
  7. Remove the crank pulley by first removing the 7/8" crank bolt. If you are unable to remove it by hand, you can rent a puller for free at most auto parts stores. If you find the crank turning too easily, either put the car in 5th gear, or remove the starter (two 14mm bolts) and wedge a screwdriver into the flywheel to prevent it from turning.
  8. Assembly is the opposite of removal.

Questions about this modification
Q: I don't have an 84-86 NA. Can I swap the maxima alternator into my Z31?
A: Yes. The alternators are all the same style. You can put the 89-92 Maxima alternator into any year/style Z31. I did this write-up for the 84-86 NA simply because that's the style I have. And my old alternator died.

Q: Do you have to change the pullies?
A: Not if they are the same style. You cannot (well, you can, but you really shouldn't) use a V belt on a multi-ribbed style pulley. And you shouldn't use a multi-ribbed style belt on a V style pulley.
You don't have to swap the two pulleys I swapped. You can swap the pulley on the alternator. I just didn't want to have to swap the alternator pulley every time I had to swap alternators. I also don't find it fun trying to loosen a nut on a shaft that is designed to spin.

Q: Do you have to get a shorter belt?
A: Depends. If you use the standard Maxima alternator's pulley, yes. The Maxima pulley is slightly smaller than the Z pulley. And as you'll notice, generally, the alternator is adjusted to it's limit on the adjustment bar. If you don't get a smaller pulley, you'll end up with a really loose belt and you won't be able to tighten it far enough. If you use the original pulley, you don't need to get a smaller belt.

Q: What exactly is the advantage of swaping Alt. from a Max to a Z?
A: On a stock car, there isn't any. The Maxima alternator is 90 amps to the Z's 70 amps. But if you install a lot of electrical parts (electric fan, big stereo, electric water pump, extra lights, etc.) you'll need a bigger alternator so you don't drain your battery. It has no actual performance advantage, and actually may even rob a small amount of power from your car.

Q: If I use the stock Maxima pulley, what size belt do I need?
A: This is actually really simple. First, find the length of the original belt. Style doesn't matter. Second, find the style of the needed belt. Third, find that style belt in the original length. Finally, grab the next smaller size belt. For mine, this was the 935 mm long micro V (or multi-ribbed style) belt. I believe the original belt was 945 or 950 mm long.

Miscelaneous pictures:
Maxima Alternator:

1984-1986 300ZX NA Alternator:

Comparison of the alternators:

Comparison of the pulleys:

Connecting the new alternator: