Serpentine Belt Squeal

[roo_ster]

Had the alternator replaced on my 1989 F-150 reg cab 4x4 302 V8 Borg Warner manual 4sp.  No AC.

They also replaced the serpentine belt, as the old one was cracked.

Now, I get a pretty loud squeal.

I was wondering what the usual treatment for this was?  Squirt some silicone on the belt?  Wave a can of WD-40 in the general direction?  String up and bleed out an Earth First-er over the motor bay?

Much appreciation for any tips.

[Gewehr98]

Buy a Glock.

[Tallpine]

Ear plugs 

[Triphammer]

Not sure if you're joking about lubing a belt. Get a can of belt dressing, tacky rubbery sort of stuff in a spray can. It'll quiet down & maybe wear in so it won't squeck anymore. New belts w/o dressing usually don't squeal for more than a day if everything is right.

 Just thinking, how's your battery? If the new alt is putting out a good charge & your battery is low there's a lot of extra drag on the belt. Does the squeal go away in a couple miles or is it continuous?

[BobR]

Make sure the belt tension/er is set correctly. Belts usually squeal because they are a touch loose.

bob

[41magsnub]

Did they put the right belt on?

I once had an alternator replaced (under warranty) and they put the next size down belt on it by mistake.  To make it work they had to bypass the idler pulley.  Squealed like crazy when I started it.  Made them keep it and fix it.

[Triphammer]

Serpentine belt usually has a spring loaded tensioner. If that was weak whoever replaced the alt & belt should have noticed it. Maybe not, worth checking.

[Brad Johnson]

Make sure it's routed correctly.  If the underhood routing sticker is gone it will be in your owner's manual.  Also, the part number should be printed somewhere on the belt.  A little Google Fu should tell you if it's the right belt for your application.  Finally, if those two scenarios don't pan out, they may have gotten grease on the belt during the fix.  Happens.  The solution is to pop it off and give it a scrubbing with soap and water.

Brad

[geronimotwo]

Not sure if you're joking about lubing a belt. Get a can of belt dressing, tacky rubbery sort of stuff in a spray can. It'll quiet down & maybe wear in so it won't squeck anymore. New belts w/o dressing usually don't squeal for more than a day if everything is right.

 Just thinking, how's your battery? If the new alt is putting out a good charge & your battery is low there's a lot of extra drag on the belt. Does the squeal go away in a couple miles or is it continuous?

my thinking has always been that belt dressing is for v-belts.  I don't think it's recommended for s-belts.

[bedlamite]

my thinking has always been that belt dressing is for v-belts.  I don't think it's recommended for s-belts.

Belt dressing works great on multiple ribbed V serpentine belts. You might be thinking of toothed belts, they shouldn't need it.

[never_retreat]

My truck squeaks when its raining out. No idea why it does it in the morning and theoretically there should be no rain under the hood.
I had an undersized belt on my truck and I think it lead to the premature death of the power steering pump. It is a ford so PS pumps are a problem anyway.
I don't know how I got one that was too small, there are only 2 options for the truck one or two alternators. Ant there is a big difference in them.

[French G.]

Most multi Vs have auto tensioners, I've seen some that don't, retarded Subaru to name one. Second the notion to check the belt routing and part #, auto tensioned shouldn't squeal. Look at the idlers, make sure they are turning. Finally, are we sure it is a belt squeal? A new tighter belt may have been the straw that broke the camel's back for a crapped out idler bearing, or the newly installed alternator may be making the horrid noise. I typically like to take the belt off and turn each pulley and the alternator by hand to feel for issues.

[lupinus]

That's what happens when you take it to the redneck garage with dudes playing banjos out front.

[230RN]

Factoid to remember for someday, somewhere.

Most elastomers expand when they get cold, shrink when they get hot.

Found that out one day when I bellyached about the V-belt on my car squeaking in cold weather and not in hot.  I ast a jen-you-wine ASE automotive engineer about that and that's what he said, and he worked for Gates.  (Rubber, not Bill.)

[gunsmith]

http://www.youtube.com/watch?v=9gLN3QoN-q8

my belts squeal all the time, I figured it was dust....I'm probably wrong though, as hard as it is for you folks to believe it.

[Jocassee]

Mine was squealing in the morning and when damp. I replaced it this week and the noises are gone.

[Brad Johnson]

Forgot to mention above, cheap belts can also be bad about squealing.  Make sure they used a decent brand like Dayco, Gates, Goodyear, Motorcraft, etc.

Brad

[bedlamite]

Forgot to mention above, cheap belts can also be bad about squealing.  Make sure they used a decent brand like Dayco, Gates, Goodyear, Motorcraft, etc.

Brad

FTFY. We use a number of belts on the machines at work, and repairs are tracked. Goodyear consistently breaks after a couple months where Dayco and Gates last years on a machine.