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MG Midget and Sprite Technical - Crank Shaft Bolt Lock Washer

Just received this as a lock washer for the crankshaft bolt. Is this correct - shouldn't it have a tab or cutout to fit with the key/keyway?

Graeme Williams

They seem to have been supplying those for at least 30 years. I found one the other day and it had been in my mother's garage for about that length of time, as I didn't see the point of fitting it.
Dave O'Neill 2

Is this on an A series engine, if it is, look in the pulley and you will see a half moon cutout, fit the lock tab to the bolt, tighten up the bolt, locate the half moon cutout, and knock the lock tab over into the cut out, that locks one side of the lock tab, now with a pair of large pipe grips bend the lock tab over the flat of the bolt opposite the half moon cut out,
Andy Tilney

I'm sure the one fitted last had a tab on it. However, from my experiences with tabbed lock washers on the rear axle, it is often that the tab gets torn off as the final tightening of the nut drags the washer around with it.
Is the half-moon cut out present on the harmonic style of pulley?
Graeme Williams

it is often that the tab gets torn off as the final tightening of the nut drags the washer around with it.Thats why you don't knock it over until the bolt is tight,yes there will be a cut out in your pulley, with reference to nuts dragging lock tabs round with them, its good practice to rub up the contact side of the nut on a sheet of emery paper to remove any burs and to make it smooth
Andy Tilney

I think you will find that this type of soft metal lock washer doesn't achieve very much.
Daniel

Same with a B series engine--
One side of the washer tapped into the pulley groove and the other side bent up against a flat on the bolt
I can't recall seeing one with an internal keyway tag
You're not getting mixed up with the camshaft lockwasher by chance-it is how you describe with an internal tag
Cheers
willy
William Revit

I think you will find that this type of soft metal lock washer doesn't achieve very much, Well I have never seen a crank pulley bolt come lose, after correct tightening of the bolt, and correct installation of the lock tab,so it must achieve something. A.T
Andy Tilney

Well I have and most if not all pro race engine builders don't use it.
Daniel

Thick hard washers from APT in the USA.

Daniel

Daniel, are we not discussing standard A series engines, not non standard engines used for racing, which is different altogether, as I said correct installation of these components will ensure a successful outcome. A.T
Andy Tilney

Most standard locking tabs are made of a fairly soft metal that is malleable and won't crack when knocked over to secure. Race applications may of course be different. Andy was replying to the original question about how the apparently plain circular locking washer worked.
GuyW

THanks everyone. I can understand the half moon idea and talking to Alan A this morning it was that style we recently used. I can remember knocking the tab over the bolt head (I did that) but Alan must have done the half moon bit when my back was turned. I was convinced the washer had a tab but my memory is obviously failing a bit (after a couple of weeks, it seems).

As Willy says, maybe I mixed my recollections up with the tabbed cam washer.
Graeme Williams

I have never used the standard crankshaft pulley lock washer/tab on our 1380. Just a good dab of Loctite on the bolt threads, and tighten it up to the standard 70 lbf. ft. torque.

Getting it undone needs the full power of a 1/2" drive impact wrench!
Richard Wale

Loctab and Loctite ...
Paul Walbran

I dont like that washer idea, i get the concept ..but im not feeling it

Tbh... i dont think you need an actual locking washer as paul says, you have to have at least a 1/2 inch electric /air ratch impact wrench to get them off

Other wise its a a jambed up flywheel 6foot metal pipe and 800lbs of good ol boy red neck fat hanging over there belts to free it up
1 Paper

This thread was discussed between 03/06/2017 and 09/06/2017

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