Jeff 97 Formula

Since my original alternator started to squeak, I recently purchased a new alternator from Advance Auto Parts, which I thought was going to be a Remy. Well, it says ToughOne on the box, but is completely new. When I googled the part number 91411, it came up as a Remy part number for the car.

Anyway, looks just like the stock one (except with a gold pulley and the middle piece is gold too). Install went fine 2 nights ago, sounded a lot better with no squeaks or other unwanted noises. Last night when I started it up (which was almost 24 hours since the last time it was running so it was very cold), the alternator was making a weird "scratchy" sound, and also sounded like "shot" bearings. The noise only happened for the first 30 seconds of running, and did not return for the rest of the time driving. I then tried it this morning and the noise was not there. Left it to cool off all day, and tried it tonight and the noise was still not there.

Any ideas why a brand new alternator would make a strange noise the day after install for just 30 seconds? Thanks!

EDIT -- I would also like to add that the plastic fins on the fan look as if there is almost no play between the fin and the case, when compared to the old alternator. So I am wondering if the plastic pieces expanded/contracted just enough for them to rub on the case for that little bit, and wore it away which is why the noise has not returned.

Jeff 97 Formula

Tried it again just now (cold start). There was some minor "clicking" sounds from the alternator for about 5-10 seconds then went away (nowhere near the noise I heard 2 nights ago).

Is it possible that the new alternator just needs to be "broken in"? I'd really hate to take it off and bring it back just to be told "nothing's wrong with your new alternator". Thanks!

LS6427

iTrader: (2)

I've never heard clicking noises from the two alternators I've replaced in 14 years on my car. Never heard about breaking them in either.

If its working and its quiet, drive it for awhile. I've always gotten Lifetime warranties at PepBoys....so I bought my first replacement alternator for like $120, and I've returned it once for a free replacement. When this one goes I'll go get another free one. That deal can't be beat. But two alternators in 14 years, I'd say they're pretty good units. especially when its just a 15 minute job to swap them out.

.

1 FMF

iTrader: (1)

yeah, alternators don't break-in. they just break.
best/easiest thing to try in my opinion is leave it installed, pull the belt off it, and spin the pulley by hand. feel for any bind. also check endplay by pulling the pulley fore and aft, if you can shift it fore and aft a significant amount that would explain the fan rubbing noise. alternators are pretty simple mechanically, if it only did it once then maybe the noise didn't come from the alternator, or the belt shifted on the pulley or something.

Jeff 97 Formula

Ok, the noise has not returned. But something strange is happening.

I've been keeping a close eye on it and remembered when the noise happened the fan blades looked as if they were touching the housing. Since I haven't heard strange noises after that and it works fine, I left it alone.

Today, I now noticed the blades are 1mm away from the housing. I took the belt off, the alternator is spinning freely with absolutely no binding. I also tried (as you suggested) to pull the pulley fore and aft and there was no noticeable play). Still working fine with no noises, but I don't know what to do at this point.

blackthunder50

I just bought an AC Delco unit for $170. Looks exactly the same and haven't had any issues.

sjsingle1

iTrader: (1)

https://ls1tech.com/forums/generatio...-failures.html

good read on alts.....and why rebuilds are a crap shoot

Jeff 97 Formula

Thanks....but mine is 100% new, not rebuilt.

sjsingle1

iTrader: (1)

not many alts are new.....most are remans....with china parts in em........the super duty rectifier is 80$ alone in my alt