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Hi all
my car came to me with a horrible belt squeal. The power steering pump and alternator were off kilter from the other pulleys, I seemed to have straightened out the PS but the alternator is still off, it seems like it needs to roll up and towards the rear of the car. The one issue I have is the alternator is a 1/16” away from the valve cover, I’m also not sure the belt is correct, it seems like it needs to be longer. I am still trying to figure this out. The brackets I believe are aftermarket and could be the problem but not sure, does anyone have pics of the full assembly and or real bracket pics to compare to. Or possibly good factory brackets to sell if that is my issue.
I appreciate any help
I see 2 things.
1 NMT1957 The bracket that runs over the top of the PS cap can be rotated end over end to give more clearance to check the fluid.
2 OP your belt sits pretty low in the pulley groove. IF, it is riding on the bottom of the pulley, a wider belt will give it more traction as it is off the bottom and you get more side friction. But, I do also remember reading that Chevy was concerned about throwing belts, and did spec deep pulleys for some 390 and 400 hp engines. A wider belt will not be the same length as the narrower one, and may take a bit of trial and error to fit correctly.
A glazed belt can sometimes be fixed by wiping it down with acetone. Do not use any of the belt dressing goop available.
I did use a few washers to get my bracket/pulleys to line up better.
In looking around it should be a 3 groove, now to find one. In a perfect world I’d like an original, is that going to be impossible? If so who should I buy an aftermarket one from?
im still not sure this will help the alternator being out of whack. I will try a wider belt as well.
I believe the water pump pulley on all 69 427’s should have 3 grooves. You pulley has two grooves. That in itself may be causing you a problem.
While I’m not sure of this either I know on the 68s it’s a 3 groove deal, I assume it should be the same on a 69. Not saying this is the issue but I’d look into it.
In looking around it should be a 3 groove, now to find one. In a perfect world I’d like an original, is that going to be impossible? If so who should I buy an aftermarket one from?
im still not sure this will help the alternator being out of whack. I will try a wider belt as well.
Not sure who the best source would be. Not a bash to any vendor but generally speaking anything from Paragon or Corvette Central you shouldn’t have any issues with.
Also, check your crank pulley. Make sure that isn’t the source of your weirdness. Given things have been changed around over the past 50 years by various bubbas (yes I’m a bubba too) anything is suspect TBH. Keep in mind that the OE water pump for the corvette was a short unit which was unique to the corvettes. You might find that you have a couple of things wrong.
In looking around it should be a 3 groove, now to find one. In a perfect world I’d like an original, is that going to be impossible? If so who should I buy an aftermarket one from?
im still not sure this will help the alternator being out of whack. I will try a wider belt as well.
Check this thread out for your pulley. Part # 90840 was from a Mercruiser boat engine.
I used one on my 68 years ago and it worked fine. In fact I just got another last week from ebay for a fraction of a correct one for a future BB project.
Hats off to 540vette on this one.
Not sure who the best source would be. Not a bash to any vendor but generally speaking anything from Paragon or Corvette Central you shouldn’t have any issues with.
Also, check your crank pulley. Make sure that isn’t the source of your weirdness. Given things have been changed around over the past 50 years by various bubbas (yes I’m a bubba too) anything is suspect TBH. Keep in mind that the OE water pump for the corvette was a short unit which was unique to the corvettes. You might find that you have a couple of things wrong.
The original cast number was 3856284 which you would see cast on the pump. Chances are it’s a replacement you have. I do not believe this was unique to the corvette big block. This pump was used on many Chevrolet big blocks from 1965 thru 1969. Check to see what number is on your pump and look it up to see if it’s a correct replacement for a “284”.
Last edited by ed427vette; Mar 9, 2021 at 09:51 AM.
69 427 alternator bracket questions
