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Belt alignment help

67MPRFAN

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Hello all I'm having issues with my belt coming off at high rpms. What have anybody done to help fix the problem

Thanks for pointing me in the right direction

0722211736a_HDR.jpg 0722211736.jpg 0722211736_HDR.jpg
 
Take the belt off, and look carefully at the pulleys for damage, specifically pinch points or damage caused by rust. Also, check the grooves for taper issues like excessive wear. Look at the belt itself for any kind of damage as well. Make sure there's no problem with the mounting of the crank pully....like start the car for a few and look for runout or wobble..... same with the bearings on the alt and water pump... give them a spin too. Check the mounting on the alternator while the belt is still off... any movement?? If so, the alternator will bow out as you tighten the belt. Take your straight edge and lay it flat (90 degrees from how you show in pix) alongside the pulleys to look for proper depth, and make sure the straightedge is long enough to reach all the past both sides of the pulleys you are checking. Finally, don't overtighten.... and use a belt tension gauge to be positive.... In the HVAC world, I use a Browning and it gets me by, but there are others specifically for autos I'm sure. Can you provide better pix of the mounting on the alternator side??
HTH, Lefty71
 
This is a new belt I purchased this morning. I spun both the alternator pulley and it seems fine same with wp pulley because the other time this happened belt actually broke I spun it by hand just get some water moving threw the engine. I do notice that the belt shakes between alternator and crank pulley

0722211806_HDR.jpg
 
I know this sounds simple but are you sure the belt is tight enough.
Should not be shaking between anything unless a bearing is seizing up
But it sounds like you ruled that out.
Also is that a straight edge in the picture showing your alignment is good
Between w/p and alternator ?
What about crank pulley alignment to either of those ?
Throwing out ideas.
 


Here's what the belt looks like with engine running
 
I know this sounds simple but are you sure the belt is tight enough.
Should not be shaking between anything unless a bearing is seizing up
But it sounds like you ruled that out.
Also is that a straight edge in the picture showing your alignment is good
Between w/p and alternator ?
What about crank pulley alignment to either of those ?
Throwing out ideas.

Yes it a L shape ruler picture is probably hard to see on the crank pulley
 
Sure looks like your belt isn't tight enough. Why do you have the extra thick washer on the alternator bolt? Could the belt be flopping around enough at higher rpm's and hitting that bolt head? Also take the belt off and check the 2 pulley alignments with a beefier straightedge.
 
Any of your brackets bent? One picture from drivers side alternator looks like the far side looks at an angle so alternator pulley isn't square water pump pulley.
 
Sure looks like your belt isn't tight enough. Why do you have the extra thick washer on the alternator bolt? Could the belt be flopping around enough at higher rpm's and hitting that bolt head? Also take the belt off and check the 2 pulley alignments with a beefier straightedge.

Washers are there because of spacing everything out the damper is a ATI . are you saying check the alternator and waterpump pulley alignment or crank shaft and alternator
 
Washers are there because of spacing everything out the damper is a ATI . are you saying check the alternator and waterpump pulley alignment or crank shaft and alternator
I see the extra washer under the bolt head to the alt bracket.
Check both the alt and water pump in relation to the crank. Take the belt off first and spin the pulleys as you are checking. Should be able to tell if one is bent as well as in or out to far. The water pump to crank will be the most important imo. Use a thicker piece of stock than a flimsy square to rule out flex in that.
440 Source sells crank pulley shims if that would help.....
 
Wonder if those washers are pushing the bracket causing misalignment.
 
Wonder if those washers are pushing the bracket causing misalignment.

I added them because first look waterpump pulley was clearly not aligned. I'm going to pull the radiator maybe that will help with better access for checking everything closer
 
Funny this is the same setup I had on the 440 before I pulled it to replace it with the new motor only thing different is the ATI damper
 
Funny this is the same setup I had on the 440 before I pulled it to replace it with the new motor only thing different is the ATI damper
Then I would think that is your problem unless something got bent when pulling the motor? Are you certain that the balancer is seated all the way? Compare the thickness of both balancers.
 
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Sure doesn’t look like your belt it tight enough in that video.

Did you say the last belt was fine but broke, never jumped off? I had a real bad time with repop belts from Quanta. They jumped, turned inside out. Maybe try another belt. I have good luck with Continental.

You could always lower your RPM too:poke:
 
Another thing. Did you file the one offset hole on your original crank pulley to an oval to match up to the new balancer?
 
Funny this is the same setup I had on the 440 before I pulled it to replace it with the new motor only thing different is the ATI damper
Then I am thinking something alignment wise has changed.
Are you using your old crank pulley or the one off the new motor?
As 67 MPRFAN stated are you sure you got it seated all the way ?
As Lefty71 said to check the pulleys for damage / wear as that can definitely throw a belt.
Also the belt needs to be tighter than most people think.
Service manual will tell you where to check deflection at.
 
Another thing. Did you file the one offset hole on your original crank pulley to an oval to match up to the new balancer?

No I didn't but I'm going to pull crank pulley and check it in my hands for better visual
 
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