TIP: Refurbing an alternator

If your mid-90's Ford has run up it's mileage to about 100 - 150 kmiles or so, you might want to undertake a quick Saturday project that will probably save you big bucks -and inconvenience- in the near future.

Check out the back of the alternator to see if the voltage regulator (at the connector with the smaller wires) is held on by small torx screws.

If so, refurbishing which COULD be better than "rebuilding" - for a guy who is at all handy should be piece of cake.

Tools:

- 3/8 or 1/2 inch breaker bar or whatever you use to release belt tensioner,

- approp metric tools for automotive access service.

- 1/4 inch driver and small sockets plus small standard torx bits

- standard size paperclip

Parts:

- brush replacement set for your year, model and engine

- new belt, optional

- a dab of high temp bearing grease

Release tension and remove the belt, then listen carefully while you spin the pulley and check for free-spin and listen for bearing singing -you want to hear little or none- then wiggle the pulley back and forth, no sloppiness wanted.

If it fails these, put the belt back on.

Pull the connectors - they may be a little stiff- and unbolt the alternator.

With tape or marker, run a reassembly line from back housing to front housing

Remove the three housing bolts, tap the edges of the front (pulley-side) to loosen from stator (center section) and pull out by the pulley.

The stator and back housing are connected, dont attempt to separate.

Check commutator (brass rings) for galling and copper incursion into separator between them... if brush had gone and either is grooved continue on, the new brushes will just not last as long. Use fine sandpaper to smooth if ring surface is rough.. DO NOT attempt to sand more than to get the high points off.

Check back bearing for some grease and for no "wash-board" on shaft bearing surface. This is a break-point: if the bearing/surface or commutator (and SOME brushes left) is in bad shape, you may want to just reassemble and plan to replace alt.

Remove the torx screws AT THE CORNERS of the regulator and remove it from back housing.

Remove the two torx screws that fasten the brush terminals to the regulator body. make sure not to lose the nuts.

blow or brush dust from brush holders/reg and insert the new springs and brushes, note that the wire slot aligns brush terminal with proper location, do rear brush first, sliding straightened clip in to hold it in, then front brush, sliding clip further in to hold both brushes in

fasten terminals with nuts and torx screws tighten just secure, not "hard".

using just enough grease to "skin" the bearing rollers, lube the shaft bearing surface... if you're anal and are going to blow dust out of the rear housing, plug the bearing cavity tightly with paper towel.

remove towel from bearing, reinstall regulator, then carefully slide alt back together following the marked alignment.

Make sure stator and each housing mate squarely.

Install the three housing bolts and tighten alternately until very secure. not ultra tight.

Check for free-spin

Remove the clip to let the brushes drop

- - - - - - - - - - - - - -- - - - - -

Note this is a good alternative to buying a rebuilt as well... get a spare from a salvage yard and inspect it on the spot. If the alternator has not overheated or been zapped, there is every reaon to expect the regulator and diodes to last until the bearings go.

In fact, you dont know that the "rebuilt" hadnt been done exactly like this, just cleaned up more.

Reply to
Backyard Mechanic
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Hot damn. Nice post!

Reply to
CobraJet

snip

Sounds a whole lot like the generator rebuilds I used to have to do on my '64.5. Seems like I used to have to do that on an almost yearly basis way back when 17 years ago when I got it funny thing is I haven't rebuilt it since I put her back on the road 5 years ago....

bill Car: '64.5 Mustang: 260 V8, 3 sp, factory a/c, SVO cam, Performer intake, Holley 390 cfm carb, Pertronix, Hi-Po exhaust manifolds, 1.5" front & 1" rear drop, Jacobs wires, Torq Thrust D's

Guns: Colt AR15, Sig P220, Moss. 590A1, Marlin 70P

Reply to
bill

It wasn't until I had over 180,000 miles that my stock alternator went south. Of course by then the rings were chewed up. Took me about five dollars and a half hour to fix it. It lasted about another 25,000 miles before the diode board went out and discharged the battery. This time I took it to an auto electric shop and had them rebuild it ($55.00). Still in the car with 237,000 miles. With brushes as cheep as they are I'm going to make it a habit from now on to replace them with each belt change. Very cheep insurance.

Reply to
ironrod

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