Alternator V-belt pulley slipping when swapping to 3G alt

BlindAmbition

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I am attempting to do the 3g alternator swap and am having trouble transferring my v-belt pulley to the 3G alternator. I have searched for a solution and am not coming up with any results, hence this post.

I have taken the dual V-belt pulley from my old alternator and placed a shim washer between it and the new 3g alternator then attempted to tighten the nut. I can get it where it is so tight that it cannot spin, as soon as I back it off where the shaft can spin freely then the pulley also spins around the shaft itself.

Spinning the pulley does not spin the shaft with regularity, it catches sometimes but mostly just spins around the shaft. This doesn't seem right to me and I'm wondering if I have done something wrong.

I have tried 3 different thickness washers, I have tried a second pulley pulled from another alternator.

Do I need to get a different alternator? This 3g one came from a Taurus I believe. Is the issue using a V-belt pulley on the serpentine alternator? From what I've read here it doesn't seem to matter, just the threads and spacing are an issue for the nut, but maybe I'm wrong in that regard. Any advice is appreciated, thank you.

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Philip1

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It sounds like your shim washer isn't thick enough allowing the pulley to get jammed up against the housing of the alternator. Either this or the shim washer is too big in diameter and is binding up. You should be able to tighten the nut on the shaft all the way but still be able to spin the pulley/shaft.
 

Isaac Ristow

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You need to take a grinder to the face of the 3G alternator and remove some of the material that the pulley is jamming up against, The triangular gusset looking area that's raised on the face of the alt is what your fighting
 

BlindAmbition

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This is what the sticky says regarding spacing:

"The alternator bolts right in, you will re-use your existing bottom bolt, and use the top (metric) bolt that came with the 3G alternator.

Those with V-belt drives, you will have to shim your V-belt pulley out slightly (about 2mm) to keep it from rubbing on the alternator housing. I used a flat washer that was under the pulley nut. There is just BARELY room for the pulley nut to thread on, I had to leave the lockwasher off. I recommend using a threadlocking compound for safety."

When I tighten the nut it pulls the shaft tight against the inside of the case, there are some screw heads for a bearing retainer that rub the inside of the shaft/stator/whateveritis, the pulley itself looks to be spaced correctly. I picked up another 3g serpentine alternator today and will see if it performs in the same manner tomorrow and post results in case anyone else encounters this issue.
 

frankenwrench

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I am unaware of this makes any difference, but I used a 3g from a 95 Windstar with the 3.8 liter. I didn't have to shim anything. I just sank the nut with the lock washer. Maybe the Taurus housing is different?
 

chillman88

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When I tighten the nut it pulls the shaft tight against the inside of the case, there are some screw heads for a bearing retainer that rub the inside of the shaft/stator/whateveritis, the pulley itself looks to be spaced correctly. I picked up another 3g serpentine alternator today and will see if it performs in the same manner tomorrow and post results in case anyone else encounters this issue.

This sounds more like the washer being too big outside diameter though?
 

typ4

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They are all the same, you have a spacer issue of some sort, OR maybe some casting flash on the case. Check the pulley step on the back against the 3g pulley.
This is the reason I didnt leave the 6G on my truck, no way to machine the case if I got stranded with a bad alt,LOL
 

typ4

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This is what the sticky says regarding spacing:

"The alternator bolts right in, you will re-use your existing bottom bolt, and use the top (metric) bolt that came with the 3G alternator.

Those with V-belt drives, you will have to shim your V-belt pulley out slightly (about 2mm) to keep it from rubbing on the alternator housing. I used a flat washer that was under the pulley nut. There is just BARELY room for the pulley nut to thread on, I had to leave the lockwasher off. I recommend using a threadlocking compound for safety."

When I tighten the nut it pulls the shaft tight against the inside of the case, there are some screw heads for a bearing retainer that rub the inside of the shaft/stator/whateveritis, the pulley itself looks to be spaced correctly. I picked up another 3g serpentine alternator today and will see if it performs in the same manner tomorrow and post results in case anyone else encounters this issue.
The stator should not be anywhere close to the retainer screws, maybe the internal shaft spacer is missing/ wrong
 

BlindAmbition

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The pulley is not even close to touching the ribs pictured above. I did grind away on the face just in case, however that is not where it is binding. It is binding internally. I put the pulley on a different alternator and used a 1.2mm thick spacer and it fits great, no issues at all that I can tell. Fits tight and spins the way it should.

Likely my fault as I disassembled the first 3g alternator to paint the case, though I never tried to fit the pulley beforehand.

Thanks for all the help folks

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BlindAmbition

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And if it matters, the first one was from a Taurus, the second one was from a 96' E series, though I cannot tell a difference.
 

Isaac Ristow

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And if it matters, the first one was from a Taurus, the second one was from a 96' E series, though I cannot tell a difference.
Mine was from a taurus I had to grind the face a bit on mine as I read on a write up somewhere but all I can think is your black one is bad or you misplaced a shim or something inside
 
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