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I thought I’d write up my experience replacing my alternator as it was an extremely challenging job and there are some tips that I didn’t find in my other searches.

Anyone who can do this job in under 5 hrs has a lot of mechanical experience. I do the majority of work on my vehicles and I really struggled with this – just due to how tight the space is to work in. This is not an exhaustive DIY but, combined with the other write ups and video’s out there should give someone a pretty good idea.

The best/other videos and write-ups are here:

Tools & Supplies
Lots of sockets, ratchets, extensions, swivels etc. A swivel head 3/8” ratchet is essential
Pneumatic ratchet (or battery)
Torque wrench
Impact gun
Metric wrench set
Pry bar (12” or so)
4 or 5mm allen key
Red Loctite
New serpentine belt if yours is old

Steps:

Disconnect battery

Jack truck up both sides

Remove passenger wheel

Remove passenger side skirting at the front to access engine compartment

Remove skid plate

Remove sway bar bolts (17mm) that bolt it to the frame – it will just swivel down. My bolts were rusted in so I had to spray copious amounts of penetrating oil on them and run them in an out a number of times to get them to come out. If you can spray them with penetrating oil the night before that would be best. There are holes in the frame to spray them with.

Drain radiator and remove coolant hose infront of power steering pump and alternator. I didn’t do this but the hose really restricts things so it would have sped things up dramatically.

Disconnect the wiring to the power steering pump that is right behind the skirting. You need this space as open as it can be.

Remove the serpentine belt – 14mm bolt on the tensioner and rotate it CCW I think. Lock it into place with a 3 or 4mm allen key.

Remove power steering pump. There are two 14mm bolts that hold it on. You have to access the bolts from the wheel well through the holes in the pulley. One bolt you can see and it is at 12 o’clock (from the front of the truck). This is the long bolt. Start with a ratchet and as soon as its loose switch to a pneumatic or electric ratchet as you can only get 3 clicks or so with a manual ratchet.

The other shorter bolt is in the 3 o’clock position and is blind. Same thing here as it is even harder to get at.

Pry out power steering pump and bungy it up to something higher up in the engine.

Remove the clip for the main wiring harness at the bottom of the engine and remove the connector for the oil pressure sensor.

Remove the wiring on the alternator.

Start removing the bolts and nut on the alternator. The top ones are easy to get to and you can use an impact with a long extension coming from the top.

The bottom bolts are a real challenge to get to. Remove the bracket holding the hardlines to the alternator. 12mm bolt. The hard lines will move enough to get a socket on the front. The rear bolt is a real PIA. I ended up using a double wrench to get enough torque on it to crack it. If you have everything removed you can get to it with a ratchet and a swivel from in the passenger wheel well. I found this out putting it back on. I am not sure if you could get enough torque on the bolt with a swivel to break it free.

Pry the alternator off towards the passenger wheel. Watch for the sleeves that will fall out from the bottom bolts. I only had a sleeve on the front one.

Take the alternator out the bottom. Some guys take it out the passenger wheel well but I tried and could get it.

Put the new alternator in the reverse that it came out. Make sure the sleeves are in. Torque all 14mm bolts to 32 ft*lbs. Attach electrical.

Before you put your power steering pump back on, push out the rear bushing, otherwise it will be too tight. I didn’t have a hammer that would fit in the space so I improvised by taking the small 14mm alternator bolt, threading it into the bushing a ways and then putting a shim behind the bolt and backing the bolt out against the shim (which needs to hit the other ear of the PS pump frame). I used a 3/8” drive by ¼” socket for a shim which worked perfect.

Put the power steering pump in and torque it up. Connect all electrical and reinstall skirt. Reinstall passenger tire.

Put serpentine belt back on following the diagram. Unlock tensioner.

Put coolant hose back on if you took it off and refill rad with coolant.

Install sway bar – use red Loctite and torque to 51 ft*lbs. You can put the front bolts in first and then swivel the sway bar up. Put rear bolts in and tighten.

Reinstall skid plate

Reconnect battery

Start truck. Note that, depending on how dirty your MAF sensor is, you may have very low RPM’s (mine were ~400) which isn’t fast enough for your alternator to produce proper voltage. Your ECM will calibrate itself in a short period and will increase the RPM’s. I cleaned my MAF sensor which fixed that problem.

All told I was into it for probably 12 hours. Putting it back together went considerably quicker but that was still 3.5hrs or so.
 

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Thanks for the great write up. I experienced battery problems and started with replacing the battery, cleaning contacts, etc. The new battery died one morning a week later and I read it with a meter and it had only 0.5 volts on it. I new I had a short in the system somewhere. I checked the amp draw on the negative side and it kept popping my 20amp fuse in my meter. I Checked all relays, fuses and cables. The last thing was the Alternator or Starter. Both of these jobs on my 5.7 2007 Limited was looking like a nightmare, but every video I could find was for the 4.7l My buddies suggested we get the alt out and start there. YOUR TUTORIAL SAVED THE DAY! once out the alternator went for a ride to O'reilly's for a test. The person hooked it up to the machine and the machine said their adapter cable was bad before the test even started. AW HELL! So, off to Auto Zone where 2 new salespeople were working and I basically showed them how to test it... By following the machines instructions. :) The Lamp/Diode test failed right away. The short was found!... So I ordered one up and put it in. What a &^$(&$

I fought with the steering pump for a good hour before returning to this post and reading about the bushing. SAVED ME AGAIN!

All said and done she fired right up and had low RPM. I drove her around the block and on/off the freeway and before I got back home she was her old self.


Where do I send the case of beer, Paul?

And yeah... I was about 14 hours into it over two days.

Cheers,

Eric

2007 Tundra 5.7 Limited w/Tow... and only 117,000 miles
 

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Thanks for this- it was hard to find any good info.
One change, though: I found, after breaking off two nuts inside the frame for the sway bar, that biting the bullet and removing the rad took much less effort. One of the few things on a Toyota that is reasonably easy. I’m from up north, and everything here rusts. The rad came out easy, and the alternator came out the top. It WILL NOT come out from the wheel well.
Good post; thanks again. Off to the weld shop to figure out how to reattach the sway bar.
 

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Great write up, definitely saved me a ton of money.

One note, and everyone's experiences may be different, but I absolutely was able to take it out through the wheel well. Need to rotate the alternator into the correct position (don't ask me what that position is, it just takes a few tries) after removing it but still was much easier than removing the sway bar or radiator. The extra lines from the towing package makes it more difficult but still doable.
All that being said, this is the worst placed alternator I have ever worked on. WTH Toyota.
 
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