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Removing the alternator on a 3.5 (5 speed)

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I'm trying to replace my alternator. I've seen some reference online to either 1) removing the mounting bolts on the alternator and then removing the voltage regulator control plug, ground, and positive from the bottom.


I don't see enough slack in the leads to remove them after removing the mounting bolts. It seems any attempt to do that with the alternator just hanging in there by the leads, would also wreck the oil pressure sending unit, as one attempted to put enough torque on the ground and positive bolts to loosen them.



or 2) removing the battery and battery tray, and removing the voltage regulator control plug from the top, and the ground and negative from the bottom before removing the mounting bolts.


My battery tray appears to be spot welded and glued in. There is no room to get your arm down in there to get to the voltage regulator control plug, around some other wires and power steering items.



I do have an electric radiator fan, so once the alternator is removed, getting it out will be no problem. I'll either pull the electric fan out, or rotate the sway bar up, and pull the alternator out from the bottom.



Anyone ever done this and have ideas?




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I just finished this job. Time consuming and annoying for sure. I pulled the fan shroud, fan and upper radiator hose. Then loosened the belt tensioner and pulled the belt off. At that point I found it easiest to remove the lower alt mounting bolt, allowing it to swing down towards the motor. That allowed me to pull the alt harness plug and go after the small 10mm hex nuts that attach the ground and harness loom bracket. Its a pain for sure. A ratcheting 10mm box wrench would be worth its weight in gold in this scenario. once the items are off the backside you can pull the long through bolt and pull the alt up and out the front. Installation is reverse of course.

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Ratchet wrenches are the S#it!! I got both SAE & Metric. They cost a pretty penny but worth every one of them.


Maybe HF has their our brand like Princess does up here. I lucked out, both 12 pc sets at my local swap meet, new, for under a $100-WINNING! And Princess has their own brand-seen them on sale lately for under $100.

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I got it done, it took about 5 hours. And then in a second it was undone.


I will write up my version later. But when I got to the last step of tightening the lower bolt, the head snapped off.


I was using a torque wrench to the factory recommended 26 nm. The only thing I did wrong was there was a little bit of corrosion on the threads, so I used a dab of antisieze. I knew there was a danger of overtorquing with antisieze, but that's the first time it's happened to me.


Now I get to do it all over again.




Sent from my FRD-L04 using Tapatalk

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So I finished replacing my alternator. I am going to get my original Hitachi alternator rebuilt and have it on-hand, since consensus seems anything but a new or rebuilt Hitachi alternator is unlikely to last long. But because I didn't want to be down for that time (little did I know the lower alternator bolt would break and leave me down for a week anyway), I got a junkyard alternator. Unfortunately I wasn't able to get a Hitachi one from the junkard. It was a 13900 built in Malaysia. It was a greasy mess, so cleaned it with a can of CRC Lectromotive electric parts cleaner, which worked great, and got it tested at Autozone.


It turned out I couldn't see well from the top, so I was wrong about not being able to get my arm between the battery tray and the power steering pump. I'm 5'6" and medium build with fairly large forearms, and I could do it with a fair amount of struggle. If you were significantly bigger, especially in the forearms, you might not be able to do this.


Any specs quoted below are from memory, so I recommend verifying in the FSM before doing this. Here are my steps -


  • Remove the plastic windscreen on the underbody
  • From right behind the steering rack, reach up and remove the alternator ground screw
  • Use a flat blade screwdriver to push the plastic latch on the wiring harness off the metal bracket attached to the alternator
  • Put a magnetic finder on the alternator mounting nut (to prevent it from getting lost, you don't want to lose this in the power steering rack)
  • Loosen the nut on the front of the idle pulley FIRST!
  • Release the belt tension by unscrewing the bolt on the bottom SECOND! - Otherwise you'll screw up the tensioner mechanism
  • Work the belt off


  • Remove the battery and plastic tray
  • Optionally you can loosen the alternator top bolt, and remove the bottom bolt to possibly gain a half inch for doing the 2 steps below. I was able to barely do it without loosening the alternator.
  • From the top, remove the voltage regulator plug (release button faces the firewall)
  • From the top, remove the positive lead by pushing the rubber boot out of the way and removing the nut


  • Here is where my truck will deviate a little bit (I have an electric radiator fan) - remove the radiator fan and shroud
  • Break both alternator mounting bolts loose
  • Unscrew and remove the top bolt from above
  • Find its nut with the ear below your engine
  • Remove the bottom bolt from below
  • There is no good way to describe how to jigsaw the alternator out of position, but you basically have to move it a little to the passenger side, and bring it forward in front of the radiator. It will take some wiggling and muscle to release the alternator top mount from the engine bosses. Be a little careful, in the manual transmission, the oil level sensor's plastic socket is right below the alternator.
  • Carefully bring the alternator across the radiator to the driver's side, and then Tetris it out between the radiator and anti-sway bar. There is an inch more room here that makes the difference



  • After the 2nd replacement, I decided not to reattach the metal wire harness bracket to the new alternator. The wiring harness seems much stiff enough to support itself.
  • Work the new alternator back into position the same way the old one was removed
  • DO NOT USE lubricant on any bolt threads or nuts. Wash them off with parts cleaner if necessary. You may want to replace the lower alternator bolt if it looks corroded. The head of mine broke off when tightening it. I believe it is a M8 1.25 20mm flanged head bolt. I used a class 10.8 I found at Autozone.
  • Put the top bolt in first
  • Optionally put in the lower bolt, but you could wait until after you wire the positive lead and you might gain half an inch of clearance for the positive lead and voltage regulator plug
  • Get someone to spin the top bolt for you while you get underneath the car and start the top nut onto the threads, and get the ear seated against the alternator mounting arm


  • From the top, reattach the positive lead FIRST! If you try to do the ground first, you'll be unable to correctly seat the positive terminal between the two nuts on the positive stud of the alternator without cracking the plastic insulator. Someone did this to the junkyard alternator I had. So I swapped the insulators with my old one.
  • From the top, reattach the voltage regulator plug
  • Reattach the negative lead from the bottom
  • Tighten the alternator top bolt (60 NM)
  • Tighten the alternator lower bolt (30 NM)


  • Put the belt back on
  • Finger tighten the idler pulley nut and back it off a quarter turn
  • Tighten the tensioner belt (I have another thread with guidelines for this. The short version is hand tighten with an extension and no wrench, then use a wrench 2 full turns for a new belt, and 1.5 turns for an old but good belt)
  • Tighten the idler pulley nut (25 NM)
  • Reinstall the radiator fan and shroud
  • Reinstall the battery plastic tray and battery
  • Reinstall underbody windscreen



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  • 3 years later...
Thank you for writing all that! I am going to attempt it tomorrow, since I had jinxed myself and the alternator died today. 

I did this job a few months ago. It sucks badly. Getting everything reconnected is the most difficult part.

Sent from my Pathfinder
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