The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: BigJim on 06.04. 2019 00:48
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Hello chaps, just a quick quiz on if to use spring washers on top of a flat washer when mounting my engine onto the frame. Am fairly certain that i should be using those serrated lockwashers but i don't have any so it's flat washers nice and tight or pop a spring washer on aswell? Well chuffed at mo as have managed to refit engine onto mounting plates after much wrestling. The last bolt looked well out of line but then jumped in from the other side?
*bright idea* *countdown* *beer*
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Hi BigJim, I use stainless steel internal tooth lock washers, readily available from most bolt suppliers in the world. They really can't be reused, so I buy boxes of them.
Cheers
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Spring washers sound like a bad idea. I think that they can limit the clamping force of a fastener done up really tight, such as an engine mounting stud or bolt. The split in the washer can open up.
Use thick plain washers and re-check the tightness after a few rides. You may find that they settle down and need no more tightening after some time.
I’m not condemning the other recommendations for fancy toothed washers, because I know nothing about them.
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Nice plain washers and Loctite on every nut and bolt...Works for me.
Swarfy.
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Hi,
Spring washers are normally flat by the time the nut is fully torqued. At this time it is equivalent to a solid flat washer, and its locking ability is nonexistent. They have been found to actually loosen the bolt under vibration even faster than a joint with no washer.
Star washers are used for electrical grounding, sometimes used for spring action but mostly for locking action by biting into the mating surface. Although this washer does provide some locking action, it damages the mating surfaces. These scratches can cause crack formation in highly stressed fasteners, in mating parts, or both, as well as increased corrosion susceptibility.
Best wishes...
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bsa were not silly when they used the fine thread form on the engine mounting studs, if over the years these have been changed to a mish mash of bolts and threaded bar chuck the lot and get the proper fasteners that when done up don't come loose, unless its say a 5/16 or 3/8s cei stud made in some far away place that you can throw the nuts onto from 20 paces *pull hair out* *bash* *rant*