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Tdog71
Samba Member
Joined: November 01, 2011
Posts: 453
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 Posted: Sat Jun 16, 2012 5:06 pm Post subject: Generator nut keeps loosening |
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| I will drive my 66 for a few miles and will begin to hear a chatter coming from generator pulley. I will check it with my 19mm wrench and the nut is loose. I tighten and it comes loose again after a few miles. I just replaced the generator too. Stock pulley on generator and crank. Why is this happening ? |
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Bruce
Samba Member
Joined: May 16, 2003
Posts: 17285
Location: Left coast, Canada
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| Posted: Sat Jun 16, 2012 7:00 pm Post subject: |
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What torque are you using?
How many shims are there between the two halves? How many on the outside under the clamp?
My generator's nut is 21mm on the hex. Maybe the smaller contact area of your 19mm nut is biting into the clamp?
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| overheard at the portland Swap Meet... wrote: |
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Tdog71
Samba Member
Joined: November 01, 2011
Posts: 453
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| Posted: Sat Jun 16, 2012 7:25 pm Post subject: |
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| Bruce wrote: |
What torque are you using?
How many shims are there between the two halves? How many on the outside under the clamp?
My generator's nut is 21mm on the hex. Maybe the smaller contact area of your 19mm nut is biting into the clamp? |
3 shims inside, 5 outside. I meant it is alternator, not generator as I converted. I did not measure torque, I cinched it tight by hand with a 7 inch box wrench |
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Bruce
Samba Member
Joined: May 16, 2003
Posts: 17285
Location: Left coast, Canada
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| Posted: Sun Jun 17, 2012 11:29 am Post subject: |
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| Tdog71 wrote: |
| 3 shims inside, 5 outside. |
I don't think that's enough. Find 5 more.
Since you're having trouble, get your torque wrench out and do it up to 40-47ftlbs.
_________________
| overheard at the portland Swap Meet... wrote: |
| ..... a steering wheel made from a mastadon tusk..... |
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berliner
Samba Member
Joined: December 27, 2006
Posts: 440
Location: west coast canada
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| Posted: Sun Jun 17, 2012 12:12 pm Post subject: pulley |
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Mine was doing the same thing,turned out the pulley had separated from the hub.It was a"Genuine German"part,manufactured in China.Pull it apart and have a look.
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Donnie strickland
Samba Member
Joined: December 21, 2009
Posts: 2403
Location: Moody, AL
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| Posted: Sun Jun 17, 2012 5:20 pm Post subject: |
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| Remove the belt, and both halves of the generator pulley. Grab the generator shaft and see if you can shake it around, to check for play which would indicate bad bearings. |
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Tdog71
Samba Member
Joined: November 01, 2011
Posts: 453
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| Posted: Mon Jun 18, 2012 9:20 am Post subject: |
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| Thanks all. New Made-in-China unit, so it is what it is. I think I am under-torqued. I didn't know you could get it up to 40-47ft lbs. I torqued it harder with a regular 1/2 inch socket wrench while I was out and it seems to be holding. The little 7 inch box wrench wasn't getting it done I will get my torque wrench out tonight. |
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The Phil
Samba Member
Joined: March 05, 2011
Posts: 1371
Location: Tucson
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| Posted: Mon Jun 18, 2012 9:47 am Post subject: |
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| Bruce wrote: |
| Tdog71 wrote: |
| 3 shims inside, 5 outside. |
I don't think that's enough. Find 5 more.
Since you're having trouble, get your torque wrench out and do it up to 40-47ftlbs. |
Are the generators and alternators different? The alternator on my 66 only has 7? shims.
I too have 19 mm nut. and I've never used a torque wrench, just a big 19 mm wrench and a screwdriver to keep the pulley from moving and just tighten down the bastard. It never has come loose on me.
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My '66 Baja Build Page http://www.thesamba.com/vw/forum/viewtopic.php?t=456365
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Bruce
Samba Member
Joined: May 16, 2003
Posts: 17285
Location: Left coast, Canada
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| Posted: Mon Jun 18, 2012 11:47 pm Post subject: |
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| The Phil wrote: |
I too have 19 mm nut. and I've never used a torque wrench, just a big 19 mm wrench and a screwdriver to keep the pulley from moving and just tighten down the bastard. |
Without a torque wrench, we don't know if his arm applies the same torque as yours.
When you're having trouble, eliminate sources of error.
| The Phil wrote: |
| The alternator on my 66 only has 7? shims. |
Did you know that there are two different shim thicknesses? Some are ½mm, some are ¼mm. If you have all of the thick ones, he may have the thin ones.
I've also seen a couple of different heights of the bell shaped clamp directly under the nut.
A good test is to assemble the top pulley and tighten the nut with no belt in place. If you don't have enough shims, the outer half will be loose.
_________________
| overheard at the portland Swap Meet... wrote: |
| ..... a steering wheel made from a mastadon tusk..... |
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The Phil
Samba Member
Joined: March 05, 2011
Posts: 1371
Location: Tucson
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| Posted: Tue Jun 19, 2012 12:11 am Post subject: |
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| Bruce wrote: |
| The Phil wrote: |
I too have 19 mm nut. and I've never used a torque wrench, just a big 19 mm wrench and a screwdriver to keep the pulley from moving and just tighten down the bastard. |
Without a torque wrench, we don't know if his arm applies the same torque as yours.
When you're having trouble, eliminate sources of error.
| The Phil wrote: |
| The alternator on my 66 only has 7? shims. |
Did you know that there are two different shim thicknesses? Some are ½mm, some are ¼mm. If you have all of the thick ones, he may have the thin ones.
I've also seen a couple of different heights of the bell shaped clamp directly under the nut.
A good test is to assemble the top pulley and tighten the nut with no belt in place. If you don't have enough shims, the outer half will be loose. |
the first part strikes me as a common sense thing that totally blew by me.
the second part was something I had no idea about. that's an interesting piece of trivia there. Thanks for learning me. 
_________________
"In case I don't see you, good afternoon , good evening, and goodnight."
My '66 Baja Build Page http://www.thesamba.com/vw/forum/viewtopic.php?t=456365
Free from the evils of facebook Dec 2012. No other Social Media. |
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