: Squealing Belt on 1986 Fleetwood Brougham

Lord Fleetwood
04-22-11, 06:22 PM
I have a problem with a squealing belt. It seems to be connected with the alternator. Whenever too many items draw power, the belt starts to squeal. For example, if I have the blower on with the headlights and then hit my brakes, that's enough to start the belt squealing. I can't isolate it to any system since any sufficent combination of power-drawing accessories being turned on will cause the squeal. I've tried several different belts, all being tensioned over and over. Many people told me the alternator belt was not tight enough, but I have factored that out by tensioning the belt many times with many different levels of tension, some quite tight. It would also appear not to be the alternator as the old alternator I had did it and so does the current new alternator. The only thing I can come up with is that when enough power is drawn something is putting enough resistance on the alternator to make it difficult to turn and thus squeal, but I don't have a clue as to what. The problem is worse in cold weather and is worse at low speeds. For example, on the highway it takes more to have it happen or it may not even happen; stopped at a light it is more likely. When the belt starts to squeal everything in the car dims (lights both interior and exterior) and does so until the squeal stops. I can get the squeal to stop usually by turning things back off (like the blower). It is quite annoying and is eating up belts. If anyone has any idea what is causing this and how I might fix it, I would appreciate it greatly.

04-22-11, 06:30 PM
maybe it's the pully on the alternator that's squealing? Never had a squeal related to the electrical draw. I'd get the alternator checked.

04-22-11, 08:55 PM
Wow---a tough one to figure out.When you say it`s "eating up belts",do you mean the belts are actually ruined?
I had squealing belt last year and all it took was a tightening of it to fix----since you `ve said you`ve tried different tensions seems to rule that out.
It`s possible you may have/had 2 bad alternators---what brand alternator do you now have?

04-22-11, 10:38 PM
My car does the same thing. I installed a new battery and the store didn't have the right size, so I had to get a smaller one. Every morning, over the winter, the alternator got into an argument with the battery. Check your battery and make sure it is a 75 series.

Have tightened or checked the other belts? Running an electrical accessory causes strain on the engine, which slows the belt drive and can make the other belts squeal; it might actually be your power steering or AIR belt that is making the noise.

Have you had your belts tightened by a professional? One of things that can cause premature belt wear is over tightening. Other things to check for would be pulley misalignment (the alternator belt should be perfectly inline with the groove on the crank pulley) and a dirty/rusty pulley surface.

04-22-11, 11:33 PM
Yea, make sure all the other belts are tight too. Also, check all the pullies to make sure no melted rubber or debris is in the grooves.

04-23-11, 11:00 AM
I'm not an expert on what braughm had what engine but it sounds like a 307 issue; I had a Ninety Eight Regency that did that.. Those 307's had a lousy belt arrangement. I used to tighten the alt belt all the time. I think it may have actually been the water pump belt that drives that pulley instead. The pulley may be worn too after years of slipping. I never did get mine sorted out before the rear end died.

Lord Fleetwood
04-23-11, 05:09 PM
Thanks to all who have replied so far. I'll address some of what you guys have mentioned. I had someone mention it could be the pulley, but since it did it on both alternators (one of which is pretty new) and since it only does it during relatively great electrical draw, I would like to believe that it would not be the pulley. Is there a way to check that?

By "eating belts" I mean that the belt is being worn faster than it should be. If I take the belt off (which I have done many times to tension it) I notice excess rubber on the pulley and the belt. This also leads me to believe that it is, in fact, the alternator belt that is squealing since it would make sense all of that friction is wearing the rubber right off the belt and possibly glazing it. Unfortunatley I am unsure of the brand of the alternator since it is rebuilt and I got it at Advance Auto. The casing says "Delco-Remy" on it and "Made in the USA" but also has a sticker on it that says "Made in Mexico", which is kind of funny. If it is the wrong alternator, how might I check? I know this may not mean anything, but it does fit in perfectly physically.

As far as the battery goes, the only thing I have to say to that is that my friend actually borrowed the car recently for two weeks and he put the battery of the car he was fixing (a 1997 Deville) into my car to see if it changed anything. He told me that his battery, which had a higher amperage rating, actually made the squealing considerably worse. I am not sure how to interpret that (or if it is a coincidence), but perhaps someone here might. I'll check the battery and see if it is wrong in some way (though at least it fits in just fine).

I did have the belts tightened by a professional last year. I didn't have the squeal for about a week or so after, but then it started up again. I don't recall if that is coincidence since I didn't run too many items during that week, or if it really did work. Though, if it did work, it didn't last long as it only stayed that way for a week or so.

I haven't tightened the other belts in a while, so perhaps I should do that just to be sure. I will try that and see if it helps. It sometimes starts up when the wheel is turned, so that might be a clue as well. I will also check the pulleys for debris. The parts of the pulleys where the belt goes are not rusted, but after all of this squealing they very well could have rubber on them. I cleaned off the alternator pulley a few times, but the engine pulley was harder to reach so I don't think I did a great job. I will also check the alignment of the pulley, though if it were out of alignment I don't know how I would fix it being that the whole assembly for the alternator is solid metal. In any event, the belts are fully in the grooves.

I will try these things and report what works (hopefully) and/or what doesn't. Once again, thanks to all. It is appreciated!

04-25-11, 02:04 AM
I too am having an identical problem with my 87 Brougham.... and i have also done everything that you have done Lord Fleetwood.... keep up to date if you fix!!! I do not know what else to do aside from replace all pulleys? (something i didnt want to do)

10-22-13, 01:09 AM
My 87 brougham does this something I have replaced belts and water lpump but still squeals... please help!!


My dad and buddy noticed the power steering belt is not running true but when we moved them out to run true it was running into other belt any ideas?

10-22-13, 01:21 AM
Have you considered that one or more of the electrical draws are actually pulling more than normal, which might be dragging the alternator too much? For example, if the heater blower bearings are shot, it might still work, but it may be slower and drawing much more current. Other current draws might exist even when those visible accessories are turned off, like if there is a short someplace.

Another thing to be aware of is the alternator rebuilds are often a mis-matched combination of parts. I think you have a standard 10si alternator, a very common GM unit. However, they came in ratings from at least 37 amp - 100 amp. The rebuilt unit might have a case stamped with one current rating, but an armature and coil windings that could be a totally different rating. I suggest connecting a voltmeter, and turn on the electrical accessories one at a time and see if it is able to maintain the voltage. If you are going down the road so it is turning 2000 RPM and it won't maintain voltage with the heater, headlights, and wipers on, something is wrong. It may just not be capable of producing enough current.

Just tossing out a couple items worth checking, as you seem to have covered the alt bearings and belt tension.

Big Al

10-22-13, 01:38 PM
I have used Belt Dressing to good avail but that was purely a belt thing. My father used to simply hold a bar of soap on the belt for a bit as it ran and that would do it too. :p

10-22-13, 02:09 PM
Buy a krikit gauge, you can find them in stores really cheap and if not online. Then you can check and adjust the belt tension as necessary. The 307 allows you to adjust the tension through the slide bolts that you loosen, put tension on the belt, and then re-tighten.

10-23-13, 04:37 PM
Tell us how the alternator belt is routed. Is it just to the water pump or does it wrap around the crank pulley as well? the rear wheel drive 4100's had belt squeal problems if the smog pump belt was loose. That 4100 alternator belt just wrapped around the water pump and under load, the alternator would cause the pulley to slip on the smog pump belt. That was the cause of the squeal.

11-15-16, 09:13 PM
Did anyone ever figure out a solution? My 87 brougham does the exact same thing. I can put headlights on and it'll squeal. Cut then of and its fine. New battery, New water pump, New belts, and new alternator

11-16-16, 09:33 AM
Loose belt! New belts need to be re tightened sometimes.

11-16-16, 03:09 PM
And, once they squeal... they might never be non-squealers even if you tighten them. They get glazed from slipping, and don't grip the pulley well...