Alternator Longevity?

I think the consensus is drive it until you need a new alternator. If it's that big a deal, buy the replacement alternator and keep a spare belt and some tools.in your truck if needed.

That being said when mine died I drove 45 minutes home in the dark on just my battery

 

Ohh one thing I added to my truck years ago that I really love having is this, a built in voltmeter.
I pulled the driver side cigarette light outer outlet out, broke apart that connector so there is just female spade terminals, connected to the male spade terminals and pushed the voltmeter into the cigarette outlet hole. Fits like a fucking dream, granted I would need to take the dash apart if I wanted to remove it.

$34 Blue Sea Systems 1733 Mini OLED DC Voltmeter, Yellow

https://www.amazon.com/gp/aw/d/B01CZ2ZXKM?ref=ppx_pop_mob_b_asin_title

 

Thanks everyone for the helpful replies. I have a reman Denso alternator on my shelf ready to go in as soon as my idler bearings arrive in the mail. I've only had the truck less than a year so it gives me a peace of mind not having the truck stall on me somewhere plus its part of catching up on maintenance. My 2000 4Runner V6 with 250k is on a junkyard alternator I installed years ago and still kicking I like how Toyota alternators don't go out often. Only reason I had to replace alternator on the 4runner twice is because the valve cover gasket killed them.

 

2010 145k mine just quit new year day. Picking up truck tomorrow from shop. Way to.cold to replace it myself

 

Regardless of brand, brushes have a fixed lifespan that's determined by their length. Decades ago, I brought in an alternator (Mitsubishi) for a preemptive rebuild (brushes and bearings) at 180-200K miles, and the rebuild shop (back when we had them) said they couldn't believe it was still working as there was nothing left of the brushes. So, I'd say change brushes at 150K as a minimum. I just swapped my Tacoma alternator out for a rebuilt Denso at about 150K as I do the rural 4WD road thing in the summer; I don't want to break down in the middle of nowhere and wait two days standing around in BFE waiting to get an alternator from civilization.