Hitchcocks Forum

I've just been looking at one of my Redditch crankshafts and noticed that there is no slotted sludge bung like the others.it just has a punch mark in the centre and a ring where you would expect to see the edge of the grub screw. How do I clean out the big end?

is this a twin or a single crank shaft the 3 different types of plugs I have seen on the twins are the Alloy screw in plugs with allan key socket ,steel domed caps press in and secured with a wire circlip simular to the piston ring circlips is this the ring you are describing , The third type had a slotted screw on the edge of the sludge trap hole screwed on the crank shaft web the sludge trap hole was not threades nor was there a grove for the circlip I sent a photo to our Host and he had never seen one like it ,I can only think that this screw held down a little shaped spring strip like a contact breaker spring that pressed down onto the steel plug . It will be interesting to hear if any one else had come across this .If you see nothing is holding this bung in you could try drilling a small hole in the center and screw a selft tapper in long enough to be able to grip it with mole grips .Perhaps a good clear close up photo of it may help .Good Luck

This is on a single,The others have a staked slotted grub screw. this one just has a circle of about the same diameter as the grub screw, with a dimpled centre.

UPDATE Curiosity got the better of me and I split the crank, turns out it's a double row roller big end. seems to be brand new too...(still had clean copper grease under the big end nuts) so it can go in the bullet trail bike cases. The crank it has come from differs from a Bullet crank only in that the primary side has a taper + key shaft instead of splines for the engine cog. - A G2 maybe??

Could be G? I'm pretty sure the G2 Bullet had a splined shaft from the beginning although the size increased in 1955. REgards, Mark

The shaft is also hollow, - If that helps narrow it down. The roller bearing is also interesting as it has no cage. It's just a double row of rollers built up with grease. Side float is controlled by the big end pin which has side walls as part of the pin.