Alternator Replacement - A Saga (1 Viewer)

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As many failures I get with reman denso units from napa both alternators and starters. I'd bet on just bad luck and I'll be forking over the coin for a new unit given availability. One thing to check though after multiple failures is the charging/starting harness and engine/chassis grounds via simple voltage drop test, this can cause both battery or alternator failure. Make sure you're in spec I rarely see more than 15mV of drop on either side though most manufacturers spec out much higher.
 
During my lunch break I pulled the cover off the latest OEM alternator that failed to see if there were any signs of visible damage.

From what I see, it appears there is some corrosion on one of the rectifier leads, which I am thinking may be the cause of the intermittent whining noise and low voltage (on the dash gauge and ScanGauge) I experienced.
IMG-6690.JPG
 
Update -

The Denso reman'd unit I am running from NAPA has been performing well so far and have had no issues with the exception of a short period of time when the voltage was 12.7-13.0V at idle. Typically I observe idle voltage at 13.1-13.3V.

I had our local starter and alternator shop, Dayton Quality Starter, rebuild the used OEM unit on the shelf with a bad rectifier, they did a complete tear down and rebuild, included; bearings, brushes, rectifier, bead blasted the frame components, turned the comm (I'm probably forgetting something). The voltage regulator tested good so they re-used it. Cost was about $110 for the rebuild.

I plan to install this rebuilt unit when I do the radiator over the winter.
 
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jerryb said:
I haven't seen new bearings in denso rebuilds, nor regulator.
rectifier yes, brushes yes. I do wonder though, and assume now, that rebuilt densos don't automatically come with a list of new stuff.
I have two. My original was not the OEM stock unit at 180k.
What I did was redo the first one while I waited on the second to arrive. By the time it did my first one was redone and better than a rebuilt denso.
I thought that's weird, but at least there's a new rectifier on it and brushes. But old reg and old back bearing. Also old brush holder.
Oh well I guess.
My only concern about mine is the non oem regulator. BUT it's been great for at least 35k miles.

I wouldn't just install a new rebuilt denso without taking the cover off and looking at it. It's pretty easy to educate yourself if you don't know anything about alternators.
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Where did you buy the new components for the rebuild? I currently am rebuilding and need: rectifier, regulator, brushes.
 
There's the place that Paul uses, their website seemed better but different prices for certain things. They are all different. Early alta and late alts- all different. It also seems that transpo regulators are the norm at the 3rd party websites.
 
jerryb said:
There's the place that Paul uses, their website seemed better but different prices for certain things. They are all different. Early alta and late alts- all different. It also seems that transpo regulators are the norm at the 3rd party websites.
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IDK who paul is or what website he uses. Mind sharing? Thank you much.
 
LCReunion said:
So I literally just finished typing up a step by step R and R for the alternator as I just did it twice this weekend...with help from mudders. I take out the three bolts from the PS pump and that let's it move enough. No line disconnect, or reservoir, or bleeding needed after. I too pull it out the top.
My advantage is my wife also being my co-mechanic(yes I am very lucky). The extra hands makes it much easier.
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So, your sig says you have a '99, and the original post says he has an '06. I believe 99s have a 100-amp alternator, and later years have a 130 amp, and there's a big size difference. You may very well need much more room to get the later alternator out than the early one.

I do plan to pre-emptively rebuild the alt in my '99 sometime soon, and it doesn't look hard to get it out the top. I've had it dangling there before when I had the timing belt off, just need to disconnect wires and there should be room without disconnecting p/s hoses.

I have a Maniac Electric Motors rebuild kit sitting in my workshop ready to go. It's not Denso, but I've used a Maniac EM rebuild kit in my wife's Subaru several years ago, and its been working fine for years.
 
94SRUNNER said:
I have had some poor luck with alternators. By my count I am on my fifth alternator. A bit of history...

First off, my LX is basically stock. Nothing that I can figure would cause an alternator to fail prematurely. No leaking coolant or oil from the engine that would cause failure. The area behind the alternator was and is dry.

In December 2016, what appeared to be the original alternator went out for the first time during my ownership at 137667 miles. Due to a time crunch my only option was an Autozone Duralast unit, which went in with out much issue.

The Autozone Duralast unit went out for the second time, approximately 9 months (9/16/2017) later at 150200 miles. It was under warranty, so I pulled out the bad and swapped it for a replacement Autozone.

The second Autozone Duralast unit went out approximately 10 months (7/15/2018) later at 164400 miles. :( I did not feel like dealing with an auto parts store reman'd unit. I had a used OEM unit that I had picked up and installed new brushes in. I had it tested at a local alternator shop near me in Dayton and it tested good, so I went with that as my replacement and threw the Autozone unit on the shelf.

This past weekend I had to drive to Pewaukee Lake, Wisconsin to pick up my son from my brothers and the truck ran fantastic. No issues. Started it up yesterday and it was typical symptoms, bad electrical whine and reading low voltage on the dash gauge and ScanGauge. So....after approximately 24 months and at 181104 miles I got to do it all over again.

This time I went with a reman'd Denso unit from Napa. Now I have heard the pros and cons of the reman'd Denso's, but I'll take my chances as I've got the change out time to around 2 hours.

Previously I had removed the alternator out of the bottom. This time, I felt like trying a different method. I pulled it out through the top without removing the upper coolant line or the coolant reservoir. Below how I went about it;

1. Disconnect the battery (10mm)
2. Remove intake tube (10mm)
3. Remove serpentine belt (14mm socket on breaker bar or wrench on tension pulley)
4. Remove 3 bolts that hold power steering pump (14mm deep socket)
5. Disconnect the high pressure line (17mm and 37ft-lb for reinstall) and wrap in rags and place a container of some sort to catch PS fluid. Once the flow has stopped, pull the power steering pump out of the way. I also unbolted the PS reservoir, which allowed me to set the pump back even further. Pull the high pressure line back towards the front of the engine bay and secure with a zip-tie.
6. Unbolt the alternators 12 mm and 14mm nut and 14mm bolt that hold it on
7. Slide alternator forward off mounting stud and turn so you access to the rear connectors. Unbolt the 10mm nut on the power calble and squeeze the connector to release it and pull the connector free.
10. Then, remove the alternator out the through the top. If you orient the alternator correctly you can make it around all of the various plumbing components with little effort.
11. Finally, repeat the process in reverse order to reinstall the alternator then the power steering pump. Once both are bolted and torqued to spec, reinstall the serpentine belt, intake tube and finally the battery.

Note; You may need to spend a little extra time bleeding the power steering system, so have some extra fluid on hand as you may experience spillage with this process....

Using this method, I had everything buttoned up in about 2.5hrs

This link is a good resource;
forum.ih8mud.com

100 series / lx470 alternator replacement quick tips no pictures

Just did this on my 98 LC so it is fresh in my mind took exactly 3hrs and I'm slow, If anyone has basic tips to add please do... I've done this before but not often enough to "do it without thinking" I should add it helps to have a milk crate to stand on... 1. remove plastic engine cover (10mm...
forum.ih8mud.com forum.ih8mud.com
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Wish you still lived around the corner. Looks like I’ll be doing this tomorrow if I can find a decent alternator available.
 
phishtaco said:
Wish you still lived around the corner. Looks like I’ll be doing this tomorrow if I can find a decent alternator available.
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Yeah me too. I am just up the road though...

I've had good luck a Denso I picked up from Napa.
 
Napa doesn’t show stock. The V8 t4r unit will work in my GX470 and it appears Joseph has them in stock for about $200 for a remanufactured.
 
phishtaco said:
Napa doesn’t show stock. The V8 t4r unit will work in my GX470 and it appears Joseph has them in stock for about $200 for a remanufactured.
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That is a pretty good price for a reman from the dealer.
 
phishtaco said:
Napa doesn’t show stock. The V8 t4r unit will work in my GX470 and it appears Joseph has them in stock for about $200 for a remanufactured.
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Forgive me if this question has already been answered. Can you use the 130a one from the newer models by simply changing the plug?
 
amazon prime them both and return the one you don't want..

are all years oil pump housings the same? thinking about that lower mount. The wiring part should be the easier of swapping.
search, there are plenty of guys on here that have switched- I think
 
phishtaco said:
Napa doesn’t show stock. The V8 t4r unit will work in my GX470 and it appears Joseph has them in stock for about $200 for a remanufactured.
Click to expand...

Marty...how did the alternator install go?
 
About 3 hours or so start to finish. Went in from the bottom and passenger wheel well on the GX470. Appears to be working out. My wife is driving it because my daughter decided to rear end someone on Friday so I get the rental.
 
phishtaco said:
About 3 hours or so start to finish. Went in from the bottom and passenger wheel well on the GX470. Appears to be working out. My wife is driving it because my daughter decided to rear end someone on Friday so I get the rental.
Click to expand...

Glad it went well...sorry to hear you are stuck with the rental.
 
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