DIY: Replacing 3rd gen alternator

War Sprout

New member
DIY: Replacing Alternator 3rd gen V6

What you will need:
new or remanufactured alternator
12mm Deep socket
14mm, and 10mm sockets
Di-electric grease
band-aids
gloves
electrical cleaner

Notice: While you have the alternator out, its a great time to replace the 4ga wires from the battery to alternator and the battery to engine ground.
Also, the adjuster bolt may be seized, so be ready to make a run to the hardware store for a replacement.

Because this was my first time replacing this part, it took me a little over an hour, from start to finish. If I was to do it again, it would probably take me about 15 minutes. The vehicle used in the demonstration is my 1997 limited 4x4. So let's get started!

First, whenever you park your car to replace this part, it is important to turn the steering wheel ALL THE WAY to the left. Like this:

CF4D6143-056D-493A-A158-22C86FEAF440-1472-0000011FD36C66F5_zps75e782b0.jpg



Next, open up your hood and disconnect the negative battery terminal.

699C82A9-821B-48DB-BBD9-18CFC0586C54-1472-00000121724BB0CA_zps6c21779c.jpg


This is the beast you will be removing. The alternator is located on the front left side of the engine block, (reference you sitting in the vehicle facing forward) next to the dipstick, and is connected to a drive belt. Another way to describe it's location would be 4 inches down from the engine oil cap on the V6. Mine has crud all over it because of my leaky valve cover.

2E4B3707-0A1E-4530-B90E-95737BFEE168-1472-0000011CDF49DC82_zpseb095596.jpg


And this is what I replaced it with

49A9521D-B34D-4486-9C8F-6685E7A0CE9D-1472-0000011CCED84D62_zpsda82b982.jpg


It's probably not necessary, but for the new alternator I put di-electric grease in the plug for the connector here.

37226760-23AC-467B-8F58-9A3D26D8A7DD-1472-0000011E4D4DF61B_zps0400ca59.jpg


There are 2 methods you can use to give you enough space to remove the alternator. It has been suggested that removing the battery and the battery tray works just as well, if not better. Do what you think is best, and what works for you. For this write-up, I went through the fender lining.

When turning your steering wheel to the left, it allows you to gain access to an area of the fender lining that can be removed. Because the alternator is on the left side of the vehicle, you will need to remove these grommets under the left, front fender.

92c4dac9-f01e-4695-8011-645da79dd3c2_zps6a7a6c92.jpg


After removing these grommets, you should be able to gain access to the connector plug on the back of the alternator shown here. Push in on the clip, and pull out. Some people have reported problems removing this connector due to build up, so it might be best to spray some electrical cleaner on the connector before attempting this. The connector is shown below:

F0A72D53-EA0F-4796-BD06-F092071161D0-1472-0000012023720A5C_zps8d8f22cb.jpg


9cc4b63a-d62a-4856-bb11-313d4092fa12_zps7acb8312.jpg


Back up top, remove the plastic cap covering the alternator wire, shown here. Unscrew the fastener and disconnect the wire.

fff8729d-ed18-45b4-aa23-c01adac3243a_zpsc091345b.jpg


Now you must loosen the alternator's tension to remove the drive belt that cranks it. This tension can be released by loosening two fasteners until you can slip off the drive belt. Access fastener #1 from the left fender lining.

58b9e0bc-ec10-4797-a375-88a35abbdab4_zps4e714187.jpg


Next, loosen fastener #2, located under the drive belt pulley. First photo is for reference:

9F902B27-6C2F-4651-B1C2-753AFB6D7C61-1472-00000125CAA8811F_zps1b3c919a.jpg


Second photo is the fastener itself:

9A864103-C3B3-49FF-9E81-9A083312F056-1472-00000125BFC3A178_zps8b7dd5c9.jpg


Once these are removed, the bracket connecting the alternator to the fasteners should come right out. You will need this for the new alternator, so just set it aside for now.

After removing the fasteners and the bracket, the drive belt should just slip off, and the alternator should be held on only by the top pivot bolt, shown here:

681921f1-f982-4c89-9409-e5123fced5f9_zps45d03526.jpg


This is where I needed the band-aids. This sucker felt like it was glued in (on my vehicle at least), so be careful removing it! This requires a 14mm.

7C165943-3653-4855-843B-C88BB374AAB3-1472-00000125582959C7_zps0943ff08.jpg


After removing the connector, wire, 2 fasteners with the bracket, the drive belt, and the top pivot bolt, the unit should come right out. However, I had issues from the build up, so use electrical cleaner here if you have to. Carefully but firmly remove it by pushing down until it breaks free, bring it underneath the metal that was holding it in place, and maneuver it until you can get it out through the space in between the engine bay, battery, and radiator.

OUT:

EF50CE20-E7A5-43DA-AFA4-22DD59DBB34E-1472-00000125B1DCD4AC_zpse4f845d6.jpg


OLD vs. NEW

90E949FD-8B1B-4B39-93A9-3265A7A1D845-1472-00000125AA08EA3B_zpsd14c3b8a.jpg


Installation of the new alternator is in the reverse order of disassembly. (See post #3 below)
 
Last edited:
Register to hide this ad
Assembly should be done in the following order: Pivot bolt, drive belt, adjusting bracket with two fasteners, the wire, and the connector. Once everything is assembled, connect your negative battery terminal to the battery and start your vehicle. Listen for a squealing belt. If it squeals, you need to continue to tighten fastener #1 from the fender lining to create more tension on the belt. This will eliminate the squeal.

Don't forget to return your core alternator for some $$, and replace the grommets in your fender lining!
 
Next time, remove the battery and its plastic tray. It will give much more room and you wouldn't have to remove any of the clips for the rubber splash shield.
 
While you have the alternator out, its a great time to replace the 4ga wires from the battery to alternator and the battery to engine ground.
Also, the 3" adjuster bolt may be seized, so be ready to make a run to the hardware store for a replacement. Once I had it off the alternator bracket, I had to use a propane torch to heat the bolt and work it back and forth to get it free from the adjustor post. It will make sense once you get it off the truck.

FYI. You can buy a brand new TYC alternator for about $100 at rockauto.com. They are an OEM supplier. I have been very happy with mine.
 
Last edited:
Next time, remove the battery and its plastic tray. It will give much more room and you wouldn't have to remove any of the clips for the rubber splash shield.

While you have the alternator out, its a great time to replace the 4ga wires from the battery to alternator and the battery to engine ground.
Also, the adjuster bolt may be seized, so be ready to make a run to the hardware store for a replacement.

I will add these in to the original post. Thanks!
 
Nice DIY.

My buddy is on year eight for his Duralast starter on a Ford. With the big box autos, it is hit or miss right out of the box.

+1 with removing the battery. 10x easier.
 
Nice DIY.

My buddy is on year eight for his Duralast starter on a Ford. With the big box autos, it is hit or miss right out of the box.

+1 with removing the battery. 10x easier.

I never even thought about removing the battery. It seems like it would just make the replacement more time consuming to me. Everything is right on the other side of the fender lining. I guess if your adjuster bolt is seized I could see how it would warrant more workspace.
 
@%1;War Sprout

Curious how many miles you have on your truck. My alternator went bad on mine right around 175,000.
 
I'd like to comment for anyone who is having battery / alt issues with their older 4Runner.

I had dead battery issues for years with both a red top and yellow top optima.

My yellow top still only charges to 70% capacity (charges to 100% but unplug and come back 60 mins later and it is at. 70%) but I was able to solve my power issues by doing the following:

Perform the Big 3 upgrade, specifically the battery neg to chassis wire.
Start using a $30 14v solar charger when leaving the car sitting for a few days (details in my thread)

I even have a spare alternator for when mine truly goes bad but no need to install it quite yet.
 
Next time, remove the battery and its plastic tray. It will give much more room and you wouldn't have to remove any of the clips for the rubber splash shield.

Or just lift the truck higher. I had NO issues getting to my alternator when it went out. .01

Duralast = No good!
I would fix the TOYOTA alternator.
.

Not necessairly true......


I'd like to comment for anyone who is having battery / alt issues with their older 4Runner.

I had dead battery issues for years with both a red top and yellow top optima.

My yellow top still only charges to 70% capacity (charges to 100% but unplug and come back 60 mins later and it is at. 70%) but I was able to solve my power issues by doing the following:

Perform the Big 3 upgrade, specifically the battery neg to chassis wire.
Start using a $30 14v solar charger when leaving the car sitting for a few days (details in my thread)

I even have a spare alternator for when mine truly goes bad but no need to install it quite yet.

Good idea.




One thing I don't thing people really understand, is that there are better alternators than the whimpy little 80amp that Toyota puts in the trucks.

I'm running the CS-144 out of a '95 Caddy. It puts out 140amps. Plenty to run the truck, lights, ect ect. And for <150, why not? You're spending that much to replace the measly 80amp one?

I've been running it for 5-6 months now, on the stock wiring, and haven't had any issues at all.

Just my .01......
 
One thing I don't thing people really understand, is that there are better alternators than the whimpy little 80amp that Toyota puts in the trucks.

I'm running the CS-144 out of a '95 Caddy. It puts out 140amps. Plenty to run the truck, lights, etc. And for <150, why not? You're spending that much to replace the measly 80amp one?

that was my first thought as well...
 
2002 4Runner - Alternator Replacement

Help!?!

2002 Toyota 4Runner 4x4 - $173,000 miles

I reviewed the post dicussing the necessary steps to replacing an alternator and it seemed quite "reasonable". As an overview, I'm a beginner mechanic (made this term up). The most I've done with a car is swapping the spark plugs, excluding your typical BS maintenance (filters, oil, etc).

My alternator recently locked up and snapped the belt. The Toyota dealership quoted me $960 to fix (approx $360 for alternator, $75 for belts, $500 for labor)....is this way overpriced??? Im currently trying to sell the truck so any money put in at this point is "wasted". Should I purchase an alternator from a separtae location (Oreilly, RockAuto, etc) and complete the fix myself?? Obviously this would be much much cheaper, but the added risk of completely messing something up in the engine could be devastating....

Im open to any and all feedback. This forum has proved its worth many times so Im hoping to get lucky!
 
Considering you can get a new/reman alternator for about $150 or so and a belt should run you about $30 you're looking at about $180 and an hour of your time vs. at least an hour of your time taking it to the mechanic and waiting and shelling out an additional $780, I'd say the math is definitely in your favor for replacing it yourself.

BTW, that price seems really high for this kind of job, especially for the labor. There's no way it should be a $500 labor cost for a job that even a novice can do in under 2 hours and a professional should be able to do in under 45 minutes.

I've never had to replace the alternator in a 4Runner, but I have done it in other vehicles that had it hooked up to a serpentine belt. Honestly? The hardest part was just making sure the belt was aligned correctly on all 5 or so pulleys, and I'm a mechanical moron sometimes. While I don't want to say there's no chance that you'll screw up something (after all, bolts break and other stuff pops up from time to time), I think saving almost $800 is worth the chance, especially if you're selling the 4Runner and losing that money anyway.
 

Members online

Forum statistics

Threads
278,307
Messages
3,554,054
Members
248,016
Latest member
Advally Service

Trending content

Back
Top