Changing an alternator in my Lumina

I’m planning on changing my 1996 Chevrolet Lumina’s alternator and serpentine belt soon. I’m expecting a relatively routine job, but was just wondering if anyone had any tips or things to watch out for as I do it. I’m going to use a rebuilt alternator and am changing it because the current/original alternator’s bearing is making a fair amount of noise. The car has a 3.1 liter V6.

In the vicinity of the top front of the engine should be a serpentine belt routing diagram. It’s not hard to do.

You’ll need a 3/8" breaker bar or ratchet to relieve the tensioner pulley.

While the belt is off, check all the pulleys for possible wear by rotating them while at the same time, putting sideways pressure on.

Before installing the rebuilt alternator, use a straight edge and check the pulleys for proper alignment.

This must include the alternator AFTER you install it, but before you run the engine.

Pulleys out of line will wear out the belt prematurely and also put more strian on the bearings.

Disconnect the battery first.

Change the tensioner pulley as preventative maintenance. My mid 90s Chev pulley was still working at 140k miles but the bearing was a little noisy as I discovered when installing the second new belt. As I recall the pulley was about 20 bucks at the car parts store.

With a bad alternator bearing, the tensioner pulley might not be far behind.

I replaced the alternator on my 93 Caprice a few months back. I bought a rebuilt alternator from a local shop. The owner recommended using the original pulley on the rebuilt alternator to ensure a match to the rest of the system. He switched the pulley over to the rebuilt alternator.

I’ve had no problems with noise or alignment since the alternator was replaced.

Ed B.

If there isn’t clearence to use the 3/8 square in the tensioner you can use a open end wrench on the outside flats of the tensioner housing. Once you get the belt off just leave the wrench on the tensioner and let it rest on the frame.

The bolts holding the brackets at the rear of the alternator can be difficult to get to and the plastic cable guide can get in the way. Having exactly the correct depth and lenght sockets makes quite a difference. Air tools,correct sockets,experience make this a 20 min job,good luck.