Why is my alternator belt strecthing?

I was going to ask if the light went out if you blipped the throttle but after seeing all that uck on your carb, I'd say that

1) yeah, the light was just the belt being loose
2) your belts are misaligned

 

I never thought about the bottom hole being egged out. I got all the brackets and pulleys from Jeff and Bruno D so I'm fairly sure they are correct. I have noticed that I only have to loosen the top bolt to readjust the alternator, so the hole must be wallered out a little. I'm dead sure the alternator is not sitting in line with the drive pulleys after examining it closer.
The alt is an internal regulator type and is from Advance with the pulley changed to the correct double. Any thoughts on why my A/C belt rides so low on the alt pulley?

 

Don't know if anyone mentioned this yet Ed but what waterpump are you using? Two styles short and long. The wrong one will throw everything way off. Also as you mentioned the AC belt hits alternator Pulley and it should miss it by a wide margin in 70. Some part or parts are wrong! See if you can read part #s on all pulleys and brackets as they are easy to look up in the assembly manual. Maybe a simple solution. Here are the 70 part #s for an AC 455 or heavy duty cooling and all Stage-1's: Alt pulley #1961408(my old pulley I got this off is a little rusty but should be close) Lower crank pulley --
#1375143, upper waterpump Pulley #1375146, Upper alt brace #1387139, lower AC #1231871 and upper AC #1387136. AC brackets may not show part #s but the other stuff should. Hope this helps. Best to start from scratch.

 

Dave, I have the short pump which is correct for 70 I think. Do you think the Poston S-divider could be part of the prob? Since the A/C top bracket bolts on there, is it possible that could be the reason for the belt height?

 

Ed, not too familiar with the Poston, did you check all part #s?

 

Dave, I'll have to try and check them tomorrow afternoon. Work has been crazy the last week or so due to storm damage claims so I've been busier than a cat in a sand box. Plus tomorrow evening is the monthly cruise in and the Cavalcade of Cars is Saturday (county wide old car parade down the state highway that disects the county) so I'll hopefully have time at the cruise in to check the numbers. I appreciate the list of correct ones. Hopefully it will be an easy fix so I can get it corrected b4 Indy.

 

Hope you figure it Ed. You can't drive far like that. Not without a box of belts!

 

No, you're right. One lasted to Bowling Green and one back. Indy is mega farther. I'll probably trailer up if I haven't got it figured out by then. My time is just slim with summer here and work gung ho. If I get it there maybe enough Buick minds can get a live look at it and help me figure out what the deal is. ou:

 

Ed, if you get to Indy I bet someone can figure it.

 

Running out of time here Dave. That'll be the plan I think. I'll trailer her up and hope wiser heads prevail.

 

Had a similar problem with alternator belt , various brands . On mine I finally found the problem , the water pump. when it was rebuilt the pulley flange was not at the correct position . Corrected problem with water pump shims , from Summit I think .

 

Thanks for your input on this Mike. I'm really grasping straws here trying to figure it out. The air works good and car runs awsome but the belt shaving thing is drivin' me nuts. I got little piles of rubber in various spots under the hood. ou: I'll check and see if the water pump looks misaligned today after work.

 

1970 electra, original alternator... im trying to loosen the alternator enough to take the belt off and replace it, but i cant seem to roll the alternator towards the engine enough to get enough slack. 2 bolts right? pivot bolt on the bottom, and adjustment bolt on the track at the top, and the alternator barely swings. any suggestions?

 

Start your own new thread. This one is over 13 years old.

 

"Hidden" bolt at rear of alternator? Some GM accessory drives had 'em, some didn't.

 

My belt stretches excessively during the holidays.....Jim

 

As did mine....huh!