Wiper Box Retaining Nut

[ramjam2005]

In the final stages of a full body strip-down after decades of being in storage and removing the windscreen. So, as a precaution, I decided best to remove the wiper wheel boxes now to save clipping the windscreen on the drive posts as I lift it out. (dash is also completely out).

LH Passenger side wiper nut undone easily no trouble. But the RH driver side nut is seized solid. Left some penetrating oil on the thread for few hours and on re-attempting I thought the nut finally gave way but noticed the threaded post itself had also turned. I held the wiper drive with some mole grips but it's definitely the tubular post of the wheel box also moving

So I am assuming the tubular post is somehow crimped onto the backplate of the wheel box and they have separated, then either :-

a) the wheel box is now knackered and will have to partially destroy it to remove from windscreen frame ? (Expense of purchasing a new one)
OR
b) Only thing I can think of is if I can split the nut to get it off and hopefully tack weld the tubular post to secure it again ?

Any suggestions from anyone experienced similar issue ?

Ray

[sujitroy]

I removed one from a parts car. It stripped the threads on the shaft. Not just that it was binding . I couldn't find a way to remove the gear from underneath. I can't recall how the shaft is attached, but I recall the shaft is made of ali, but the base looks to be steal. I always look for ways to save parts and money, but I think you will need a new expensive unit.
Sujit

[ramjam2005]

Thanks for your response Sujut. So looks like option a will be the final solution - more expense
Nothing to lose so may as well attempt option b but if they are 2 different metals a tack weld is out of the question to salvage it.

[ramjam2005]

Nothing to lose so tried option b , sacrificed the retaining nut with careful use of angle grinder almost down to the thread then sharp tap with screwdriver blade split the nut off. Minimal damage to thread on post so if I can secure it to wheel box base plate saves me £30+ on a new one, just a new nut instead £1.19 which I would have replaced eventually anyway for nice new bright ones.