Crankshaft nut

[Mark RobinsonParticipant]

Hi having trouble getting the castellated nut of the end of my crankshaft I’ve tried using a punch and it won’t budge and I’m just damaging it,

I’ve had a tool made but still can’t get it off. Any ideas?

[BernieParticipant]

Mark,

Those wretched nuts either work loose and cause problems or seize and cause different problems.

I suggest you drill the nut, starting with a small pilot midway between the id and od then open the hole up as much as possible without damaging the thread.  That will weaken the nut enough to be able to split it with a chisel and release the stickfulness.

When we rebuilt our engines, both Phil and I fitted specially modified hex nuts with thread locking products.  In addition, I made a lockplate from a modified flywheel lockplate.  It ain’t pretty but it is effective (and out of sight).

If you are interested I can post some pictures of both the nut and lockplate.

B….

[Hans-Peter Dürr-AusterParticipant]

Mark,
I agree with Bernie, you have to destroy the nut. It might be welded on one point to the crankshaft, what I found with all my 15-6D engines. Then we prepared new nuts with standard measures for a big spanner and the security fixed as shown in picture. Don’t mind, in the photo it’s a 15-6G engine, but our procedure was identic to D-engines. This G-engine ist entirely rebuilt in CH, its brother beside. Mark Harding put the one in the picture into my 15-6G Berline 1939.
Hans

[Mark RobinsonParticipant]

Thanks guys, Bernie will drill the nut tomorrow and take my tine not to damage the thread And yes please post your lock plate, is it like Hans?

i cant see any welding on it but i was warned of this happening i will another Aust club found he had to cut the flywheel off to remove it.

cheers

Mark

 

[Mark RobinsonParticipant]

This is the tool I made to try and get it off to no avail and also a pic of what another member here in Melb found “welded”

[Philippe AllisonParticipant]

This was my solution, a new nut and thread lock and a wire.

 

Below is the hole cut in the bulkhead by the previous owner to access and tighten the nut that keeps coming loose. This also allowed the bulkhead to flex and rendered the handbrake useless.

Good luck Philippe

[BernieParticipant]

Mark,

Nut and lockplate detail, as requested ……….

Modified nut :

         

And this is my solution for the locking plate (made from a flattened flywheel locking plate).  Note it locks the six damper fixings as well as the main nut :

N.B. – To ensure the slots align correctly with 3 of the flats on the nut, they can only be cut once the central nut is fully tightened.  To determine the correct slot positions, temporarily attach the plate by two or three of the six fixings then the edges of the nut can be located and marked by gently tapping the plate with a ball peen hammer.

B…………

 

[Mark RobinsonParticipant]

Thanks everyone,

managed to get it off after more than an hour, using the careful drill and chisel method.

After doing it my nephew asked why didn’t i just weld a normal Hex nut on the back of try Castellated nut This is probably a good idea.

Mark 

My bulkhead has also been cut and repaired.

[Philippe AllisonParticipant]

There are some hooligans ou there!!!!

[BernieParticipant]

Phil

I assume you are reffering to the earlier treatment of the original nut and not my unique modification to the locking plate.

B….

[Mark RobinsonParticipant]

A nut Gould be tack welded to the back to remove a tight nut.

[Author]

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