Probable Cause?
Thread Starter
Racer
Joined: Jun 2006
Posts: 316
Likes: 1
From: Southern California
Probable Cause?
I have a 73 SB that has been converted to a stock 75 HEI dristributor. There is a sound that appears to be coming from the top of my engine that sounds like a bearing begining to fail. My best guess would be that this is coming from the distributor.
I've torn into just every other part of the car but zero experience with distributors.
Any suggestions on checking to see if the issue is the distributor? What should I look for? What type of effort to replace/repair? The performance has been outstanding for some years now. What tuning concerns will I have by removing, repairing and replacing if the distributor is the problem?
Thanks
I've torn into just every other part of the car but zero experience with distributors.
Any suggestions on checking to see if the issue is the distributor? What should I look for? What type of effort to replace/repair? The performance has been outstanding for some years now. What tuning concerns will I have by removing, repairing and replacing if the distributor is the problem?
Thanks
Racer
Joined: Jul 2006
Posts: 337
Likes: 10
They are not complicated. Just mark the position of the rotor (I make a large cardboard template with cutout for rotor, reference four points, like the air cleaner bolt, back fire wall etc.) remove the hold down and pull her out. Inspect the drive gear and bushings (I think they have bushing, not bearings) for play. When reinstalling, use your template to set rotor posisition and drop into place. Make sure you don't crank the engine over and loose the reference.
Melting Slicks
Joined: May 2006
Posts: 2,369
Likes: 103
From: Centerville Louisiana
before tearing into everything take a long screwdriver or a mechanic's stethoscope and hold the screwdriver or scope to your ear and put it on the housings for the alternator and other items could be the alternator water pump or something else
Le Mans Master
Joined: May 2006
Posts: 7,708
Likes: 266
From: indy indiana
check the alternator, water pump and anything else the belts are hooked to. Find the sourse of the noise before unbolting stuff.
Melting Slicks
Joined: Sep 2000
Posts: 2,404
Likes: 418
From: Chester Virginia
most distributors don't have bearing they have bushings. If a bushing is worn badly then you should be able to feel movement in the rotor atop the distributor shaft. Usually bushings won't be noisey. Noisey is usually an alternator. A bad bearing in the water pump means the water pump seal may be leaking water or will be shortly. A water pump bearing would be very hard to hear due to the fan noise.
My first choice would be an alternator going bad.
Roger
My first choice would be an alternator going bad.
Roger
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Burning Brakes
Joined: Aug 2005
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From: Hudson Falls, N.Y. 76 Vette Modified L-48
Easy first......difficult later
Thread Starter
Racer
Joined: Jun 2006
Posts: 316
Likes: 1
From: Southern California
You guys have some great input. It helps to have second opinions when your first thought sometimes cloud your judgement. Come to think about it, I know the sound of a water pump going bad and this sure is a good match.
I'll post up the results.
Thanks,
Dr. Busrydr
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Loosen or remove one accessory belt at a time {if you can}, to see if one of the accessory components is causing the noise. The other alternative is the fuel pump [but it won't make a bearing-rattle noise]. I can't imagine a bearing-like noise in the distributor, unless it's a problem with the tach drive gearing or just a tach drive cable problem.
Thread Starter
Racer
Joined: Jun 2006
Posts: 316
Likes: 1
From: Southern California
My car was just picked up to go for paint. So it will be a few weeks unless I go there and do some work on it.
But I listened again this morning with just my ears and the sound does really appear to be coming from the distributor area.
Louder on accel and contant on idle. I'll get to the bottom (or top) of it before anything major happens.
But I listened again this morning with just my ears and the sound does really appear to be coming from the distributor area.
Louder on accel and contant on idle. I'll get to the bottom (or top) of it before anything major happens.