1988 S-10 Blazer 4x4 4.3.

Yesterday I started hearing a rattling noise, with an occasional clunk, coming from the front. Sounded almost like a bad water pump, but I snooped around with the hood up, and eventually located the noise coming from the Alternator. Seems the bearings are going out. I remember this happening once before - the thing actually seized and stalled the engine. At the time I had it replaced with a NAPA Gold remanufactured unit. I vaguely remembered that there was a warranty on it, but not if it was lifetime or what, so I went digging in the back of the file cabinet, and believe it or not found the receipt . . . well there was a 2-year warranty, but it's dated March 12, 1996.

So much for that idea.

In any case, it needs to be replaced. After 15 years and 114K miles I can't say I didn't get my money's worth. (Wasn't cheap either. Price was $159.95, in 1996 dollars. At least the labor was only $24.50.)

So questions then present themselves. Firstly, I can't remember if this was an 85 amp or 105 amp unit; which is recommended for this truck? I don't have a lot of electrical cruft installed, just stock radio and lights. The previous owner had fog lamps, but he removed them before selling me the truck back in 1994. I'm on limited income at the moment, so if I could get away with the cheaper part I'd take it.

Second question: it's gotten noticeably louder in the past day. I have to drive to work tomorrow; it's about a 40 mile round trip. Should I take the chance on having it seize on me before I can get it fixed, or should I rent a car for the day?

Third question. What brand is recommended? I'd go with AC Delco by preference, but I also found a Delco-Remy 100 amp unit (apparently this is now a different company using the Delco name under license from GM) which has a lifetime warranty vs. the AC Delco's 12 month/12K miles, and costs about $20 more. Plus this is a new unit, not remanufactured. OTOH who knows what the lifetime of a 22 year old truck is going to be. Any suggestions?

(I've been buying the parts myself and having the mechanic slap 'em in for me; the guy was rooking me on the parts cost. Need to know what to order.)

Come to think of it, could a bad water pump transmit vibrations through the serpentine belt so I feel them in the alternator's case?

(Edit to add: second question is moot, I made to work and back, but just barely, it seized as I was parking across the street from my house. I've got a guy coming tomorrow to fix it.)

 

bearings are junk in alt it will still work but it will have some noise

 

1) whack it with a sledgehammer

2) Buy a new Alternator and put it in yourself. All you need is a couple of wrenches and a crowbar.

it's a 1988, you've had it 15 years and ONLY put 114K miles on it? geeshh!!

But the least expensive Alternator and throw it in there.

I've got a 1998, had it for 6 years and got 228 K on it.

3) seems to me the sound from a bad water pump sounds a lot different than the sounds from a bad Alternator. The latter being bad bearing, metal, copper wire sound.

 

No, I put 114K on the alternator. I bought the truck in '94; I guess I've put ~135K on it altogether since I have it (221K now, had 87K when I got it). Most of those miles were put on before 2002, when I bought a '99 Blazer, and lent the '88 to my father, who doesn't drive much; didn't start driving it again until the '99 started falling apart on me in '09.

In any case, I bought the Remy unit. Had my mechanic slap it in; I tried myself, but I couldn't get the tensioner to move, it was frozen in place but good. He charged me half an hour's labor, which isn't bad. (Didn't wind up using the guy who I mentioned in the above post, he wanted something like $250 parts + labor and wouldn't let me supply the parts. Um, no thanks. Wound up costing me $115 altogether.)

Oh yeah. I got a sweet deal on the alternator. There's an Advance Auto store around the corner from me; rather than buying it on premises ($120 plus $10 core), I bought it online and picked it up at the store. So what? Well if you buy online, there are coupon codes you can google for. Found one for "$40 off any order over $100", which knocked the price down to $80. Moral: ALWAYS google for coupon codes before purchasing parts online. You never know how much you can save.