Alternator Disassembly

For the short period of time I had the car running, I noticed that the battery voltage when the car was running was lower than expected (hovering right above 12 volts). In addition to that, the headlights would dim when the radiator fan would turn on. Generally this could be caused by many things, such as a worn battery or poor grounding. Since I was already working on the engine with easy access to the alternator, I decided to go ahead and rebuild the alternator. How hard can it be?

I removed the alternator from the car and started to remove the voltage regulator, capacitor, and pulleys. The brushes on the voltage regulator were worn down but still doing their job. The pulley came off fairly easy but to my surprise, the woodruff key was missing. Either the pulley was removed before and the key was lost, or maybe it never came with a key. There didn’t appear to be any signs of slippage without it.

Voltage Regulator and Brushes

Slip Rings

Next came the difficult task of removing the screws that hold the alternator together. These screws are Philips head pan heads that are recessed in the housing. I initially sprayed some PB blaster into the threaded section in anticipation of a problem. Using a wrench for leverage, I gave it my first shot but the screwdriver kept popping out. I gave it a couple whacks with a hammer while applying some torque but that didn’t work either. I starting looking at other options online and found something that made sense to me. Someone was recommending using an abrasive paste, such as a valve grinding compound, on the tip of the screwdriver. The profile of the Philips head makes the screwdriver pop out because of the angle of the faces at the contact point. The more torque is applied, the more the screwdriver wants to pop out. Using an abrasive compound which increases the friction will help keep the screwdriver in place. With the first attempt, the screws came loose. Amazing!

Valve Grinding Compound

Valve Grinding Compound on Screwdriver Tip Trick

I tried using the same technique on the four screws that held the bearing in place on the drive side. This time the issue was not the screwdriver popping out, but the screw being seized in place. The screw head stripped before the screwdriver could pop out. Out came the screw extractors, which were able to remove the screws.

Screw Being Extracted

With all the visible fasteners removed, I attempted to separate the housing. I was able to get the two halves to move but they did not want to come apart. I didn’t want to apply too much force as I was worried I would damage the windings. Turns out that the outer winding or stator, is attached to the rectifier that is screwed into the non-drive side of the housing. Luckily I figured this out before I pulled too hard. To separate the housings, the stator (can be seen in red/orange) has to be pulled away from the drive side housing before the two sides can be separated. When separating the two halves, some force is required to get the non-drive side bearing to pop out of its plastic housing. The stator and rectifier can be separated from the housing after the six screws are removed.

Stator and Rectifier Attached to Housing

Stator an Rectifier Removed

The bearings are pressed onto the rotor (rotating winding) on both sides. I bought a small bearing puller on amazon for the bearing removal process, branded Shankley.

Shankly Bearing Puller

I sprayed some WD-40 into the shaft of the rotor to help the bearings slide off and installed the bearing puller. It worked really well on the non-drive side. On the drive side it worked, but it was a hair too small. The plate that holds the bearing in place was getting in the way. So even though the bearing puller was sized correctly for the bearing, I was not able to get the puller seated properly until the bearing came off a bit. This caused some misalignment which deformed the threaded extension rods of the puller. No big deal as I got the bearing and spacer off in one shot. As far as the bent spacer, I can easily replace that with a fastener in the future.

Bearing Puller Setup

Removed Bearings and Spacers

Bent Bearing Puller Extension Rod