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Timing Cover: Washers for Screws

Discussion in 'Norton Commando Motorcycles (Classic)' started by texasSlick, Nov 18, 2018.

  1. texasSlick

    texasSlick VIP MEMBER

    Joined:
    Jan 2, 2013
    What are you guys using under the timing cover screws?

    My Atlas originally had aluminum washers under the cheese headed screws. Over time the cheese headed screws got knackered and I changed to stainless steel socket head cap screws. I retained the aluminum washers as these provided Galvanic protection.

    With more time and timing cover removals, the aluminum washers became crushed and beyond use. I found some nylon washers, 1/4" ID x 3/8" OD, which fit the timing cover well, but these crush in the holes that that do not have a shoulder surrounding the washer.

    AN shows a fiber washer part # 00.0203. Is anyone using this with Socket Head Cap Screws?

    Slick
     
  2. bill

    bill

    Joined:
    Jun 1, 2003
    i have never seen washers on commando timing cover screws as OE.
     
    nortriubuell likes this.
  3. nortriubuell

    nortriubuell

    Joined:
    Aug 29, 2010
    +1 with bill. I've had eight Nortons now, and had to do a LOT of work on each one. NEVER saw washers under the screws, just had screws only. Pretty sure the timing covers were never off prior to me removing either.
     
  4. dynodave

    dynodave

    Joined:
    May 28, 2003
    Slick...buddy you're asking on the wrong forum. You need guys with pre commando experience if you want a broader experience level. Can't say I ever seen commando with washers either...
    yes aluminum washers are original(1960+) probably much more, and yes I've also seen some aftermarket red fiber ones too.

    "AN shows a fiber washer part # 00.0203. Is anyone using this with Socket Head Cap Screws?"
    Certainly not worth getting too excited about...LOL o_O
    If I had enough red washers, I'd probably use them....on a featherbed @ 7 ft/lb
     
  5. texasSlick

    texasSlick VIP MEMBER

    Joined:
    Jan 2, 2013
    Thanks for the replies, guys.

    After reading the first two replies, I went to AN Commando parts diagrams, and you are quite correct .... no washers are called out on Cdos.

    My concern is two fold. 1) the SHCS are stainless, and good practice would be to provide Galvanic insulation under the head, and 2) the head of the SHCS has minimal bearing area, and a washer will spread the load and prevent gouging the timing cover.

    These concerns apply to anyone using stainless SHCS on Cdos.

    Slick
     
    Kvinnhering likes this.
  6. Esmerela

    Esmerela VIP MEMBER

    Joined:
    Jan 9, 2017
    [QUOTE="texasSlick, post: 397021,

    My concern is two fold. 1) the SHCS are stainless, and good practice would be to provide Galvanic insulation under the head, and 2) the head of the SHCS has minimal bearing area, and a washer will spread the load and prevent gouging the timing cover.

    These concerns apply to anyone using stainless SHCS on Cdos.

    Slick[/QUOTE]

    Slick

    I use 6mm stainless washers (found them on ebay) as load spreaders under all casing SHCS, I did have to reduce the od on some.
     
    Last edited: Nov 19, 2018
  7. norton bob

    norton bob

    Joined:
    Nov 29, 2013
    My 1959 built 99 has always had the fibre washers, and leaks if they are not used. I don't like allen screws as its too easy to overtighten and strip the threads,I'm still using the original screws as fitted by NORTON.
     
  8. dynodave

    dynodave

    Joined:
    May 28, 2003
    "I retained the aluminum washers as these provided Galvanic protection."

    The threads of the stainless screws can as well corrode the aluminum cases.

    I have seen stainless hose hardware and bleeders corrode (destroy) the aluminum brake caliper bodies.
    [​IMG]
    https://www.ultratef-gel.com/tef-gel/
     
  9. APRRSV

    APRRSV VIP MEMBER

    Joined:
    Jun 26, 2016

    Hi Dave and Slick,
    Are your worries about Galvanic problems restricted to stainless steel. Why not the stock steel screws also?

    Ed
     
  10. Deets55

    Deets55 VIP MEMBER

    Joined:
    Oct 3, 2013
    Slick,
    A good dose of anti-seize should do the trick. I like the silver stuff in this application. I use wooden skewers and place a little in the threaded holes, helps cut down on the mess. Never had a problem on bikes and boats with SS and Aluminum combo.
    Pete
     
  11. texasSlick

    texasSlick VIP MEMBER

    Joined:
    Jan 2, 2013
    Thanks again for the additional responses.

    @Esmerela: I will look into obtaining 6 mm plain steel washers. Placing a stainless washer under the head of a stainless screw offers no Galvanic protection.

    @dynodave : Thanks for the tip on Tef-Gel. It is hard to imagine that it will stay adhered to the base metal when a screw is torqued down, but I will look into it.

    @APRRSV and dynodave and all: Here is a link to an easy to read and understand Galvanic metals compatibility chart: https://www.engineersedge.com/hardware/fastener_material_galvanic_13354.htm

    From the chart, plain steel fasteners into aluminum is rated "1" or no Galvanic activity. Thus no worries.
    The 300 series stainless into aluminum is rated "2" or slight Galvanic activity. Generally, 300 series stainless into aluminum poses no problems in the threads, except in a marine environment. The base metal under the fastener head should have Galvanic protection if possible. The italicized text is information not in the chart above, but from my own professional education and experience.

    @Deets55 : I use anti seize on my stainless fasteners into aluminum, as well as Rustoleum Cold Galvanizing Compound. The Rustoleum product comes in a rattle can, spray it on the threads, let dry and use. Loctite Blue and Red offers Galvanic protection per personal communication with Loctite tech support. NOTE: I am not advocating using Red or Blue on timing cover screws ... just FYI.

    @All: I have no scientific information for the following. Perhaps there is an electro-chemical chemist or physicist out there who can clarify this: Galvanic corrosion between dis-similar metals occurs on contact between such metals. This corrosion is greatly accelerated if an electrolyte (water, especially salt water) is present. The threads deep in the part are usually protected but the head is exposed, and thus the head should be given special treatment. The italics are my own thoughts.

    Slick
     
    Last edited: Nov 19, 2018
  12. Deets55

    Deets55 VIP MEMBER

    Joined:
    Oct 3, 2013
    NOTE: I am not advocating using Red or Blue on timing cover screws ... just FYI.
    Yes Slick I agree with that. FWIW I have been using the Locite purple for small screws that I don’t want to rattle loose i.e. carb tops, etc.

    Now if I can just find it!
    RE: Fast Eddie/garage thread
    Pete
     
  13. Onder

    Onder

    Joined:
    May 11, 2010
    How long does it take for corrosion to be an issue? I am keeping in mind that I live by the sea.
     
  14. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    EXACTLY !!
     
  15. texasSlick

    texasSlick VIP MEMBER

    Joined:
    Jan 2, 2013
    I would take precautions. Avoid using stainless in aluminum except with Galvanic thread protection such as Rustoleum Cold Galvanize, anti-seize, or a Loctite variant. Especially provide a Galvanic insulator under the fastener head.

    Slick
     
  16. Dano

    Dano

    Joined:
    Apr 8, 2011
    The fibre washers for fork drain plug screws should work. Andover stock them.
     
  17. robs ss

    robs ss VIP MEMBER

    Joined:
    Aug 16, 2016
  18. texasSlick

    texasSlick VIP MEMBER

    Joined:
    Jan 2, 2013
    Thanks for the tip, Rob. I have 36 flat 1/4" × 0.5" ×1/16" aluminum on order from aircraft spruce. They have good pricing and reasonable shipping cost. Now, if I only had a lathe ... I'll be using the bolt method to turn them down.

    I measure 0.410" as well.

    Also have 1/4" × 3/8" x 1/16" fiber on order. These are not AN. We will see what works best,

    Cheers

    Slick
     
  19. Matchless

    Matchless

    Joined:
    Dec 23, 2010
    I can't help thinking that you are all over thinking this. I lived by the sea for fifty years until recently, & rode to work in the winter when the roads had been salted. Not once did I have problems with electrolytic corrosion between stainless & aluminium. There again, I didn't ride my bikes on the beach. The problem I did have was with plated items, both zinc & cadmium rapidly giving up & parts turning rusty.
     
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  20. Onder

    Onder

    Joined:
    May 11, 2010
    ...which is why so many of us like stainless fasteners!
    And thinking about this, what does CNW use for protection
    as they are partial to stainless?