Author Topic: Crush Washers  (Read 210 times)

Offline Neilw

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Crush Washers
« on: April 19, 2026, 10:47:27 AM »
What are Crush Washers, and where should I use them?

 A lot of the bolts and nuts I've removed haven't had washers, which I feel can't be right!

Offline Johnwebley

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Re: Crush Washers
« Reply #1 on: April 19, 2026, 11:27:50 AM »
The screws that have alloy washers are holding the rocker cover on,

Maybe more,

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lifelong motorcycle rider,and fan

Offline exvalvesetdabbler

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Re: Crush Washers
« Reply #2 on: April 19, 2026, 12:10:14 PM »
Usually places where you need the bolt to seal properly.  Usually a soft material copper or aluminium.

Examples on 400/f

Sump nut
Front fork oil drain screw
Vacuum ports on cylinder head inlet
Allen screw that holds plunger inside front fork leg

There may be more

For high stress areas  where a soft washer loosening off over time would be problematic there are steel  washers that have bonded rubber inserts. Eg some cylinder head studs

Regards
Dace
« Last Edit: April 19, 2026, 12:20:05 PM by exvalvesetdabbler »

Offline Bryanj

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Re: Crush Washers
« Reply #3 on: April 19, 2026, 01:51:52 PM »
Most important ones on 500/550 are

1 between angled bracket and rocker cover at ends.  Alloy

2 between allen bolt and fork slider at bottom of fork.     Copper

3 on bolt holding top of camchain tensioner    alloy



There is also a thin steel shim washer that goes between the filter spring and filter in the housing that is frequently missing as it sticks to the filter and gets slung

Offline McCabe-Thiele (Ted)

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Re: Crush Washers
« Reply #4 on: April 19, 2026, 03:30:07 PM »
I have found the parts manual the best reference point.
Honda CB400NA Superdream (current money puddle)
Honda CB500 K1 (second money pit)
https://www.sohc.co.uk/index.php/topic,28541.0.html
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html
This is a neat 500 restoration in the USA.
http://forums.sohc4.net/index.php/topic,151576.msg1731556.html#msg1731556