Timing Cover: Washers for Screws

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texasSlick

texasSlick

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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
 
+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.
 
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
 
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
 
[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.
 
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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.
 
"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.
Timing Cover: Washers for Screws

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dynodave said:
"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.
Timing Cover: Washers for Screws

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Click to expand...


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

Ed
 
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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
 
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
 
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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
 
How long does it take for corrosion to be an issue? I am keeping in mind that I live by the sea.
 
Deets55 said:
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
Click to expand...

EXACTLY !!
 
Onder said:
How long does it take for corrosion to be an issue? I am keeping in mind that I live by the sea.
Click to expand...

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
 
The fibre washers for fork drain plug screws should work. Andover stock them.
 
robs ss said:
Slick
Just a thought - maybe buy some of these - put a bunch (metric bunch of course) onto a long 1/4" bolt and snug them down tight with a nut then linish them down to desired OD (0.410"?) with a bench sander.
https://www.rivetsonline.com/14-aluminum-washer/wb250a
https://www.aircraftspruce.com/catalog/hapages/flatwashers-alum.php

That way you're replicating what was originally there.
Cheers
Rob
Click to expand...

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
 
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.
 
...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?
 
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