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Squealing at 2500rpm

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Squealing at 2500rpm #1
Tim NJ Tim O Cliffside Park, NJ, USA Sign in to contact	Topic Creator (OP) Aug 30, 2016 12:26 PM Joined 10 years ago 38 Posts

'78 MGB has a squealing 2500rpm, new belt but original alternator. Only does it at 2500rpm could it be the belt or is it a bearing in the alternator?

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Re: Squealing at 2500rpm #2
dickmoritz Dick Moritz Philly 'burbs, PA, USA Sign in to contact	Aug 30, 2016 12:43 PM Top Contributor Joined 14 years ago 26,271 Posts

Spray some belt dressing or lubricant/penetrant on the belt at 2,500 rpm and see if the noise goes away. If it does, it's the belt or the fit in one of the pulley grooves. If not, it's probably the alternator or water pump bearing, and you can zero in on it with a mechanic's stethescope, or a makeshift stethescope using a long screwdriver or similar...

Dick

Errabundi Saepe, Semper Certi
(Often wrong, but always certain)

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Re: Squealing at 2500rpm #3
Ex-Calif Dan D Dayton, OH, USA Sign in to contact 1968 MG MGB GT "Bart - Yellow And Naughty" 1977 MG MGB "Red Betty" 2006 Suzuki Grand Vitara "Suzi Q" 2012 Jeep Liberty "Tommy The Tank"	Aug 31, 2016 04:38 AM Joined 8 years ago 8,992 Posts

Presuming the belt is tensioned properly?

Is the replacement belt the right length and width?

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Squealing at 2500rpm

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