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Belt misalignment

Old Jun 3, 2026 | 06:36 PM
  #1  
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Belt misalignment

Replaced the generator on my 69 VC, And the belt is out of alignment, causing the pulley fan to to hit mounting brackets. Plus fraying the belt. I’ve pulled it off several times and put back but still the same issue. I’ve been told the water pump shaft is different if you have AC, don’t know if the water pump is for a non ac car or not. Anyone else had an issue like this.
Old Jun 3, 2026 | 07:13 PM
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I had a belt misalignment after replacing a failed alternator. I discovered the new alternator had a washer behind the pulley instead of in front of it (under the nut). I put the washer in the correct spot and that resolved the issue.
Old Jun 3, 2026 | 08:27 PM
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So everything was fine with no belt/pulley fan rubbing before you replaced the alternator?

Did you save your old alternator and compare it, the pulley and the pulley fan to the new one? Is the pulley fan bigger than the pulley fan on the old alternator?
Did you replace the alternator with the exact same style of alternator?

Post a picture of how you have it mounted.
Old Jun 4, 2026 | 04:12 AM
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I suspect a missing washer on the rear of pulley
I suspect a missing washer on the rear of pulley
Old Jun 4, 2026 | 04:16 AM
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That’s my suspicion also. But I’ve heard a non a water pump has a different length shaft, I almost think my carb has ac, and this is a non ac water pump. I did not change water pump, but I have a new one on the way.
Old Jun 4, 2026 | 04:44 AM
  #6  
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If you only changed the alternator it's surely a washer placed incorrectly, or the wrong pulley. Did you take the pulley off of your OE alternator?

For that matter, it's always a good idea to NEVER turn in your core to the auto parts store (for an alternator, water pump, brake booster...). You can always have the original part rebuilt by a professional while your car is still on the road. It's not worth the $20 or $30 core. Plus, parts for our cars are known to be bad in-the-box nowadays.
Old Jun 4, 2026 | 08:59 AM
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Almost looks like the belt is going to the wrong pulley by the crank.






Old Jun 4, 2026 | 12:10 PM
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My alternator has more than a tenth of an inch clearance between the pulley fan and the alternator body.



Also I question if your pulley fan might be too big. Here's how much clearance I have between the pulley fan and the mounting bracket.


Old Jun 5, 2026 | 11:14 AM
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Had a similar problem for over a year shearing the head off of the alternator bolt due to misalignment. Finally realized it was the power steering pump below that was causing the misalignment. It had the wrong spacer on the lower right mounting bolt behind the double pulley. Corrected that spacer and everything else came into alignment. Several threads on here concerning the spacers.
Old Jun 5, 2026 | 07:23 PM
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I see 3 things that don't seem correct. #1, the fan is from a Ford. The Ford fan diameter is a bit larger. That is probably why it is hitting the bracket. #2, The pulley is aftermarket and may have the wrong V groove being too narrow for the belt. #3, I see is the amount of threads extending past the nut. It looks like about 5 threads when it should only be about 1 or 2. It is possible the correct fan and pulley would correct the problem, but it is also possible the spacer between the bearing and fan is the wrong size. The fan is a definite problem. It could be any combination of the 3.
Old Jun 5, 2026 | 07:57 PM
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The distance between the bearing and fan spacer size is 0.2 inch or 5.1 mm. V8AL also has the wrong pulley. Notice in his last pic how the belt is riding above the top of the pulley. The outside of the belt should not be past the top of the pulley. The pulley V width is too small for that belt. The belt will not grab like it should causing slippage and premature belt wear. After a few belt tightening adjustments, the top of the belt will curl and become concave instead of flat, like the pic of the OP belt.
Old Jun 6, 2026 | 04:03 PM
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Thanks @stellar I never noticed that pulley was wrong until you mentioned it! Another project for me..
Old Jun 6, 2026 | 04:47 PM
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Originally Posted by oldguy442
Had a similar problem for over a year shearing the head off of the alternator bolt due to misalignment. Finally realized it was the power steering pump below that was causing the misalignment. It had the wrong spacer on the lower right mounting bolt behind the double pulley. Corrected that spacer and everything else came into alignment. Several threads on here concerning the spacers.
The power steering mounting has three demons: two spacers and a washer between the bracket and the pump, the latter of which is a cast-iron bitch to get back in there when in the car. So, don't ever take the power steering tensioner bolt out, just take it loose. Unless the washer is already gone.
Old Jun 7, 2026 | 07:14 AM
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Any local alternator starter rebuild shop should be able to supply the correct pulley, fan, and spacer.
Old Jun 8, 2026 | 05:06 AM
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Swapped generator for a different brand, and it’s now correct. The other new one had a pulley way to close to the alternator housing
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