Author |
Message |
johnshenry Samba Member
Joined: September 21, 2001 Posts: 9364 Location: Northwood, NH USA
|
Posted: Sun Jul 29, 2007 6:23 pm Post subject: Big nut generator nut |
|
|
Found my gen pulley loose at a show last weekend, decided to tighten it up today before going out on an errand. Even with the impact wrench it still wouldn't get tight. I figured it needed more shims on the outside to allow the nut to put pressure on the outer half before bottoming out.
Taking it off, I realized that the outer half was "wobbly" as the striaght sided cutout was worn..... back half too.... and the hub was kind of munged up. I know this a common wear issue and when it exists, the pulley will never stay tight.
So I rifled my parts stash and came up with what looked like a very good 25hp pulley set and an NOS (tall) hub.
With an extra shim on the outside, I got it tight. But then I started wondering about the nut and went back to the gen parts box.
I have several thicker gen nuts, like the one on my gen, where the inner snout protrudes out past the back of the outer nut surface by about 1mm. Then I have some nuts that are much thinner. I know the fan nut is also very similar.
But can someone describe the "big" 25hp nuts unique characteristics? I assume the thinner nuts are fan nuts, and after the big gen pulley nut went away, they went to the smaller (27mm I think) gen nut with smaller hub and redesigned pulley. Is the big nut just thicker than the other 36mm nut? Are there only the 2 kinds of 36mm gen (and fan) nuts? _________________ John Henry
'57 Deluxe
'56 Single Cab |
|
Back to top |
|
|
virtanen Samba Member
Joined: January 08, 2006 Posts: 1462 Location: Finland
|
Posted: Mon Jul 30, 2007 12:10 am Post subject: |
|
|
All my pulley nuts have thickness of 14 mm and the center thread area is 16 mm. And I haven't had any tightening problems with them. |
|
Back to top |
|
|
drscope Samba Member
Joined: February 19, 2007 Posts: 15273 Location: Baltimore, Maryland USA
|
Posted: Mon Jul 30, 2007 8:08 pm Post subject: |
|
|
I can't believe you used the impact on this. _________________ Mother Nature is a Mean Evil Bitch! |
|
Back to top |
|
|
johnshenry Samba Member
Joined: September 21, 2001 Posts: 9364 Location: Northwood, NH USA
|
Posted: Tue Jul 31, 2007 7:36 pm Post subject: |
|
|
drscope wrote: |
I can't believe you used the impact on this. |
Lightly. I can throttle back my impact wrench on the trigger. That, and I was tired of it coming loose.
Keep me from munging up the pulley halves by trying to lock it down with a screwdriver too.... _________________ John Henry
'57 Deluxe
'56 Single Cab |
|
Back to top |
|
|
bill may Samba Member
Joined: August 27, 2003 Posts: 14160 Location: san diego,ca
|
|
Back to top |
|
|
EverettB Administrator
Joined: April 11, 2000 Posts: 69829 Location: Phoenix Metro
|
|
Back to top |
|
|
johnshenry Samba Member
Joined: September 21, 2001 Posts: 9364 Location: Northwood, NH USA
|
Posted: Wed Sep 05, 2007 11:20 am Post subject: |
|
|
EverettB wrote: |
Is this a 36mm generator pulley nut?
It is 17mm tall. |
Looks odd Ev, the center barrel should be longer I believe. Can check when I get home. Perhaps others can confirm... _________________ John Henry
'57 Deluxe
'56 Single Cab |
|
Back to top |
|
|
johnshenry Samba Member
Joined: September 21, 2001 Posts: 9364 Location: Northwood, NH USA
|
Posted: Sat Sep 15, 2007 7:26 pm Post subject: |
|
|
Here is an original Big nut and gen pulley hub Ev. See how the barrel extends down into the hub when installed. It also extends out beyond the bottom plane of the nut also.
Its 14mm thick as measured on the side also.... _________________ John Henry
'57 Deluxe
'56 Single Cab |
|
Back to top |
|
|
EverettB Administrator
Joined: April 11, 2000 Posts: 69829 Location: Phoenix Metro
|
|
Back to top |
|
|
Dave Haviland Samba Member
Joined: June 26, 2005 Posts: 322 Location: Burlington, Vermont
|
Posted: Mon Sep 17, 2007 3:27 pm Post subject: |
|
|
This weekend on a small zwitter shakedown cruise, the damned Big nut shook off, along with all the other parts. Luckily we were idling at a stop light. Drove it up onto the sidewalk to get out of the way and proceeded to fix the problem. Quite a crowd gathered to put in their two cents. While digging through my tool bag I realized that I didn't have my big socket. One of the by-standers thought I should use the vise-grips that were in my pile of tools. Then it came to me. The big wrench in my Hazet toolbox would work. And that it did. I may have paid a shitload for that box but it paid off. in tightening the nut, I couldn't get it tight. I think I may have lost a shim or two. We limped home and now have a 36 horse pulley in place which seems to work better. and all of those 25 horse pieces got buggered up so i guess I can throw them out. so much for correctness. but we have put 125 miles on it!
Dave |
|
Back to top |
|
|
allsidius Samba Member
Joined: February 02, 2010 Posts: 1475 Location: Norway
|
|
Back to top |
|
|
EverettB Administrator
Joined: April 11, 2000 Posts: 69829 Location: Phoenix Metro
|
|
Back to top |
|
|
lzamora Samba Member
Joined: October 24, 2009 Posts: 109 Location: Torrance CA
|
Posted: Sun Oct 06, 2013 10:40 am Post subject: |
|
|
What is the difference between the generator pulley nut and the fan nut? Both seem identical |
|
Back to top |
|
|
RareAir Samba Member
Joined: May 11, 2002 Posts: 14577 Location: 18 miles North of the border
|
Posted: Sun Oct 06, 2013 2:15 pm Post subject: |
|
|
lzamora wrote: |
What is the difference between the generator pulley nut and the fan nut? Both seem identical |
Pre '55 generator pulley is much more thicker compared to a fan nut. The fan nut will work, but visually incorrect _________________ 1947 Typ 11a
1954 Typ 117
1956 Typ 151
1959 Typ 117
1959 Typ 265
1961 356B
1966 Typ 151
1966 Typ 241 |
|
Back to top |
|
|
lzamora Samba Member
Joined: October 24, 2009 Posts: 109 Location: Torrance CA
|
Posted: Sun Oct 06, 2013 2:18 pm Post subject: |
|
|
I pulled my fan nut from generator, measured it and it measures 14 mm just like the picture posted on this same thread with the red background. |
|
Back to top |
|
|
johnshenry Samba Member
Joined: September 21, 2001 Posts: 9364 Location: Northwood, NH USA
|
Posted: Sun Oct 06, 2013 5:26 pm Post subject: |
|
|
I have since learned that the common reason why the gen pulley nuts come loose is a worn opening of the outer pulley half. I think there are some pics in the "Spy Cam" thread of me fixing one with the MIG and grinding. If the pulley disc has any "play" on the hub, no matter how tight you get the nut, the disc will shift and walk the nut loose. _________________ John Henry
'57 Deluxe
'56 Single Cab |
|
Back to top |
|
|
Suboval Samba Member
Joined: September 15, 2003 Posts: 794
|
Posted: Mon Oct 07, 2013 6:58 am Post subject: |
|
|
Bottoming of the generator nut to the generator shaft, due to missing or incorrect thickness shims between the nut and outside pulley, will also cause the outside pulley to be loose and crack. _________________ It all works on paper.
There's two things we learn from history:
1.) History repeats itself.
2.) We don't learn from history. |
|
Back to top |
|
|
RareAir Samba Member
Joined: May 11, 2002 Posts: 14577 Location: 18 miles North of the border
|
Posted: Mon Oct 07, 2013 4:36 pm Post subject: |
|
|
lzamora wrote: |
I pulled my fan nut from generator, measured it and it measures 14 mm just like the picture posted on this same thread with the red background. |
My fan nut measures 12mm, but the gen nut is much thicker at 18mm _________________ 1947 Typ 11a
1954 Typ 117
1956 Typ 151
1959 Typ 117
1959 Typ 265
1961 356B
1966 Typ 151
1966 Typ 241 |
|
Back to top |
|
|
Chrisisw Samba Member
Joined: May 30, 2004 Posts: 148 Location: Amsterdam, Holland, Europe
|
Posted: Sat Dec 23, 2017 5:17 pm Post subject: |
|
|
johnshenry wrote: |
Here is an original Big nut and gen pulley hub Ev. See how the barrel extends down into the hub when installed. It also extends out beyond the bottom plane of the nut also.
Its 14mm thick as measured on the side also.... |
Hi John,
Could you tell me how high the hub is in mm?
Thanks, Chris |
|
Back to top |
|
|
BulliBill Samba Member
Joined: July 09, 2004 Posts: 4573 Location: St Charles, MO
|
Posted: Wed Mar 27, 2019 8:58 pm Post subject: Re: Big nut generator nut |
|
|
For a 25 hp pulley on a 1952 generator with the correct 36 mm generator pulley nut (see John Henry photo above), how many (and what thickness each) shims are there? All 1.5 mm thick, or a mixture of thick and thin? Thanks!
Bill _________________ I'm looking for these license plate frames for my fleet:
Coeur D'Alene - Lake Shore Volkswagen
Mission VW - San Fernando
Thornton VW - Stockton
Thanks for any help! |
|
Back to top |
|
|
|