Life span of Alternators

Too many factors to consider. Heat, vibration, hours all effect the life. Every truck is different. Keep a spare in the bunk and replace as needed.

 

You don't even need to carry a spare...just watch your volt meter. If it starts reading low, you've probably got a problem. Figure out what that problem is, and fix it. Why buy a new part that will just get beat up bouncing around in the truck for who knows how long until you need it? Not only that, but if it came with a warranty, that warranty period usually based upon the date printed on the receipt...so it'll already be out of warranty long before you ever find out if it works.

 

So you never had anything break in the middle of the night, or long holiday weekend with nothing open and no immediate access for parts or help? Your advice to NOT have spare parts? You're smart. See you on the hook!

 

Brushless alternators are much larger and don't cool as well. The pad mounts are supposed to be much better. I keep a spare with new pulley already installed, if mine fails it's a matter of minutes and I'm rolling again. The biggest PITA is the pulley.

Alternators don't always show signs of going.

 

Alternators and starters fail whenever they decide too. Forget about time or mileage, they fail too randomly.

 

With all of those spare parts you carry around, where do you put the paying freight? I carry tools. Parts I can have delivered to me.

If you are paying attention to your gauges, you'll notice a charging problem developing long before it will leave you stranded. There is no need to carry a spare alternator, just as you wouldn't carry around spare batteries, spare drive shaft yokes, spare axle shafts, or any other large, heavy, seldom replaced part. Just because it "might" need replacing sometime in the next 5 years is not enough justification for me to carry a spare.

 

A lot of truth there! The pad mounts do live longer because of reduced vibration, but I've seen even those fail in a year or two.

 

Alot of people truck in places that a parts delivery guy would laugh at you when you asked to have it delivered. A spare alternator is good advice for anybody that trucks in rural areas IMO.

 

The truck won't die immediately when the alternator quits. You'll be able to keep running for another 150 miles or so just on the batteries. My truck fired up January 1, and the volt meter never came up like it should have. I drove 70 miles up to get loaded at my 4AM appointment time, with the lights and heater on. Idled for an hour while getting loaded, and then headed back to the house since it was a holiday and stores were likely to be closed. 50 miles from home the truck threw a code for low voltage, which would have got my attention even if I hadn't been watching my gauges. I still made it home.

That was 140 miles and an hour of idling, while running the heater and headlights...plenty of time and distance to get yourself close enough to civilization to find help. Being just a day cab, I've only got 3 batteries. If you've got more than that, you can run that much farther just on the batteries.

Pay attention to your gauges. They'll let you know if you've got a problem developing with plenty of time to get yourself to civilization where you can find help.