Exchange alternator or DIY

You could t a spares

I'm assuming that you have measured alternator output, full fielded the alternator, etc. to determine whether or not it is good or bad.

If all the alternator needs is brushes, then it is less expensive to replace the brushes than to replace the alternator. If you can get to the caps for the brushes, you may be able to replace the brushes without removing the alternator from the car.

Are you sure there is a problem with the brushes? It's rather rare. Basically they handle very little current and run on a flat surface so rarely wear out. Unlike the carbon brushes in, say, a mains motor like in a hoover.

Is all the curent carried in the static windings then Dave?

I do my own. There are only a few things that can go wrong with an alternator: the bearings, the brushes, the regulator, or in extreme cases a winding or two comes loose. I haven't ever seen a winding come loose on a Toyota alternator...I have on 'rebuilts'.

Brushes can be had anywhere. I got a set of brushes at a hardware store for $3 each. Bearings you have to get from Toyota (unless it's a standard size) for about $20 each. I did use an aftermarket regulator once, no problem, $45. So for around US$70 you can have a rebuilt TOYOTA alternator. My last rebuild only lasted 150,000 miles...that's 260,000 miles total.

I've done three sets on different cars.

In my experience, the brushes are about the only thing that wear out.

Depends on how hard it is to get the alternator on and off. If it's an easy job removing and installing it, I do the brush thing, if not I'd go for a quality rebuild. Usually replacing the brushes will get the alternator through the rest of the life of the car, not a lot to them, bushes, bearings, rectifier. Use some fine emery cloth on the commutator. There is usually a hole in the case put a nail or straightened paper clip though to hold brushes back, so you can put the case back together. After it's all back together you pull the nail out and the brushes make contact. Google it, I bet someone has details on how to do it.

It only needs a tiny current to produce lots of magnetism (check out crane elctromagnets) which induces lots of current in the stator

You missed out the diode pack. The second most likely thing to give trouble after the regulator.

Yes - more or less the reverse of a dynamo if that helps. It's really what makes them more practical than a dynamo - since there's no high power commutator needed, they can be run to a higher speed. Thus giving more useful output at low engine speeds.

Yup. A duff Diode Pack was the cause of the only alternator failure I've had. Replacing it was considerably cheaper than an exchange alternator. Mike.

Ah, noe over here t goes bearings,brushes,regulator diode pack in =

descending order. But that does include a load of ACRs :-(

Exchange cost is £262. I'm sure I can recon for less.

Is this the correct bearing puller?

Here's a youtube video showing how to remove the bushes/voltage regulator on some kind of alternator. If you have one like this you won't even have to split the case.

I can't tell from your post, but you should not have to pull the bearing to change the brushes or the rectifier.

It never appeared for some reason. Here again:

If I am splitting the unit I may as well replace the bearings. Seems sensible to me.

On most changing the brushes is a fairly simple job - some can be done without removing the alternator. I personally wouldn't replace the bearings unless they had failed.

BTW, have you found a source of spares for your unit?

You can check the length of the alternator brushes to determine if they need replacement. If they are like 2mm or shorter then a ~=A310 (~ $20 USD) brush assembly should do it. (Disconnect the battery. Remove a few screws off the back cover, and then two more holding the assembly you're there.)

If your battery has been in good shape that the alternator wasn't straining trying to charge a weak battery, then a brush assembly is probably all you need.

If you hear grinding noises then the front and rear bearings need to be replaced. This is usually >200K km. And depending on how cheaply you can source the bearings and the brush assembly, a rebuilt or new alternator with warranty may be the better way to go.

If the voltage regulator crapped out, then it may be cheaper just to get a replacement alternator (rebuilt or new).