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Blasted Samba Member
Joined: April 15, 2017 Posts: 67 Location: UK
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Posted: Mon Apr 12, 2021 11:30 am Post subject: Greasing threads on rebuild yes or no? |
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Hi,
Whats the general approach when rebuiling a beetle with respect to nuts and bolts. Is there a rule of thumb for reassembly and protection?
Do you apply any grease to the threads? Any particular type? if so, where shouldn't I put it? what about thread lock?
Seems realisitic to prevent against corrosion, but then again I dont want it all shaking itself loose.
I'm cleaning everything as I go along, wire brushing and running taps through things.
Thanks
Last edited by Blasted on Mon Apr 12, 2021 12:03 pm; edited 1 time in total |
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vwoldbug Samba Member
Joined: January 28, 2009 Posts: 1214 Location: Ohio
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Posted: Mon Apr 12, 2021 11:50 am Post subject: Re: Greasing threads on rebuild yes or no? |
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We use alot of antisieze. |
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Eric&Barb Samba Member
Joined: September 19, 2004 Posts: 24643 Location: Olympia Wash Rinse & Repeat
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Posted: Mon Apr 12, 2021 12:17 pm Post subject: Re: Greasing threads on rebuild yes or no? |
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Grease, even old used grease is good. An anti-seize is a must in high temp areas a like exhaust parts. Even the nuts on the nuts on the ends of the brake lines, and bleeder valves, use anti-seize on the threads. So nice to go back into those and have no problems loosening up after decades and many miles of daily driving.
Recommend not using taps to clean out threads unless you really have to. Too easy for less expensive taps to be slightly bigger than nominal, and often manufactures will use a purposely made smaller tap for a tighter fit. Not fun to have your VW falling apart going down the road....
Worked for a major manufacture of man lift machines. They were having a problem of special locking pins coming out, that were threaded into the legs of one model of machine. I had to bring in my copy of the Machinery's Handbook, and show the tooling dept. the section on selection of taps for thread fit.
There are generally three classes of thread fit:
A. Nut can be spun on by hand. This can be done with a tap only 2/10,000 of an inch bigger than nominal.
B. Nut can be turned by hand, but not spun on.
C. Nut requires wrench to be turned on. This can be done with tap 2/10,000 of an inch smaller than nominal.
2/10,000 of an inch is tiny change. Average Euro ancestry person has 2/1,000 of inch thick hair on their head. So 2/10,000 of an inch is 1/10th of a hair....
If you need to clean inner threads out better to either:
1. Just use the bolt that came with the nut with a little oil. If you have a lot of the same thread size, cut a notch in a new bolt like the engine tin screws have to automatically clean the threaded holes in the tin.
2. Get a set of thread chasers. Which are also great at reforming threads, where taps would just cut off mushed parts of threads and weaken them. _________________ In Stereo, Where Available! |
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Blasted Samba Member
Joined: April 15, 2017 Posts: 67 Location: UK
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Posted: Mon Apr 12, 2021 12:59 pm Post subject: Re: Greasing threads on rebuild yes or no? |
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Thanks for that, will ease off on the taps. |
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AutoMechanic Samba Member
Joined: December 28, 2019 Posts: 483 Location: Roanoke Virginia
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Posted: Mon Apr 12, 2021 2:28 pm Post subject: Re: Greasing threads on rebuild yes or no? |
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I’d use anti seize on everything related to exhaust the manifold and all of that. Preferably copper or nickel but the aluminum will work too. Loctite on things like head bolts and stuff which usually is red loctite because of its heat resistance vs the blue. Orange would work too it’s high strength like red but removable with hand tools. |
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Shane Tuttle Samba Member
Joined: February 02, 2011 Posts: 172 Location: Arlee, Montana
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Posted: Mon Apr 12, 2021 2:42 pm Post subject: Re: Greasing threads on rebuild yes or no? |
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I second using thread chasers in lieu of taps/dies. No matter what you want to use for protection, I would assure the male and female threadings are cleaned/degreased. Hardware such as body/pan bolts will be coated with LPS 3 as I reassemble. It dries to a semi-hard coating. It's very good against corrosion, yet will allow for the bolt to be removed if need be in the future.
If you want to use something on brake lines, apply anti-seize to the upper threads. Keep it away from the bottom threads. Use a very light coat. Just think of how you apply anti-seize to spark plugs.
For engine assembly, I use engine oil. I believe the torque values are in respect to wet, not dry threads.
I go nuclear on exhausts. There are your typical copper anti-seize such as C5A. That's for my spark plugs. I use nickel anti-seize for exhaust. It has a higher tolerance for extreme temps compared to the copper.
For electrical connections, I prefer to use DC4. After screwing in, say, ground straps, I remove the excess and apply a clear lacquer over the top.
It goes without saying; if anything calls for Loktite, you don't want to mix with your anti-seize. It may be painfully obvious to not practice that. However, you'd be amazed what I've seen over the years. |
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infiniteLoop Samba Member
Joined: October 09, 2020 Posts: 265 Location: Empire State
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Posted: Mon Apr 12, 2021 5:14 pm Post subject: Re: Greasing threads on rebuild yes or no? |
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I follow the philosophy that there should be something on every fastener I use. I remember seeing threads on this forum of what product people use on what fastener. |
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Eric&Barb Samba Member
Joined: September 19, 2004 Posts: 24643 Location: Olympia Wash Rinse & Repeat
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Posted: Mon Apr 12, 2021 5:40 pm Post subject: Re: Greasing threads on rebuild yes or no? |
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Forgot to mention, to also lube up between each brake line end and the nuts on them. Work the nut backward on the steel brake line and lube up the area the nut will be residing on when locked down. No more twisting off brake line ends with the nuts rusted to the brake lines. _________________ In Stereo, Where Available! |
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Busstom Samba Member
Joined: November 23, 2014 Posts: 3764 Location: San Jose, CA
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Posted: Tue Apr 13, 2021 12:36 pm Post subject: Re: Greasing threads on rebuild yes or no? |
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One point not mentioned yet is, it's imperative that you reduce the torque of any lubed fasteners by 30-45%, depending on what substance you choose to apply on your threads. Failure to heed this fundamental recommendation could have detrimental results depending on which fasteners you're addressing.
https://www-engineeringtoolbox-com.cdn.ampproject...._1693.html |
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74VWSunBug Samba Member
Joined: August 14, 2019 Posts: 35 Location: Arkansas
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Posted: Tue Apr 13, 2021 4:17 pm Post subject: Re: Greasing threads on rebuild yes or no? |
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Don't laugh - Not a joke: "Stopcock" lubricant.
As a young guy, I worked in a research lab at Union Carbide Corp - Films Packaging Div. in Chicago.
Specialty volume liquid measuring was done in the lab with graduated cylinders with the bottom drainage valve control being a glass petcock or "stopcocks." They were prone to seize together from certain chemicals, with absolutely no getting the glass-on-glass valve to work. Thus ruining a valuable & not-cheap glass lab devise.
About 5 bucks a tube in 1970's dollars & the graduated stopcock columns were about $ 30 & more, as I remember, so the lube was cheap insurance.
We bought from a chemical & lab supply company: Dow-Corning silicone "stopcock lube" in a tube like toothpaste, only about 3-4 times as big as the biggest toothpaste tube. It looked a lot like Vaseline, but was way slicker & the package said it was resistant to all chemicals & heat, & to remove it, you had to boil that part in concentrated lye to get it off if you wanted to.
The Lab I worked in was v-dub Central, with about 20 guys & girls driving 4 bugs of varying years, and two Ghias & my 'vert. The old-guy (to me) who was the v-dub Guru, swore by the stuff & said he always lubed every threaded part with the stopcock goo before tightening it down. Engine rebuilds, body bolts, mufflers... everything
Chicago-road-salt soaked muffler tip bolts & heat exchanger & fender bolts would spin off finger-loose after breaking the torque seal, if it had been properly "stop-cocked."
I still have almost a full tube in my tool-box.
Here's an ebay link I just looked up for the identical stuff:
https://www.ebay.com/itm/Dow-Corning-Fisher-Scient...wh7Rgaw0t
"LUBE-ON"
Dave |
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Blasted Samba Member
Joined: April 15, 2017 Posts: 67 Location: UK
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Posted: Thu Apr 15, 2021 2:50 am Post subject: Re: Greasing threads on rebuild yes or no? |
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Thanks for all the input guys, much appreciated. |
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