240z rear hub axles

[Robdog]

Can’t seem to find info on this, sorry if it’s has been covered.

Are the rear hub axles forged or cast steel?

Reason being, wanting to go 5 stud, however have concerns with structural integrity of the face flange with 5x114.3 pcd. would like to add material if possible.

otherwise shelling out for billet.

thanks for help in advance 

[C.A.R.]

I cant remember what they are made from, but I know of two people who have successfully welded material onto the flanges to re-drill the PCD.

 

 

[Robdog]

Thanks for the input, engineer will only be marginally happy if I weld to cast. Thought I should pursue this avenue before re mortgaging my home for billet axles

[gilltech]

Would it be more practical, maybe safer,  to go the other way, ie. weld up the alloy wheels and re-drill them for 4-stud? Just a thought...

Ignore me, bad idea...

Edited July 25, 2021 by gilltech

[C.A.R.]

1 hour ago, gilltech said:

Would it be more practical, maybe safer,  to go the other way, ie. weld up the alloy wheels and re-drill them for 4-stud? Just a thought...

BIIIIIIIIIG No No!
Aluminum alloy wheels are pressure cast & heat treated at the centres.
Aluminum welding softens the material and makes it more prone to cracking and failing.

It's actually safer to modify the stub axle flanges...

[gilltech]

Oh. Got it. Duh. Dumb idea then. Sorry.   

Only thought of it because the alloy wheel repairer guys do such great work straightening and welding up cracks not just fixing gutter rash on the lips etc etc. All of which I have had done.

Ignore me! Back to the flanges then.

Edited July 25, 2021 by gilltech

[Linton]

don't be sorry, I am sure some one else has had the same thought/idea, I didn't know that.

[Robdog]

This was a thought, could be a dumb idea, what do you guys think?

machine a ring for the backside of the flange. Drill and tap 3 existing stud holes, then bolt new ring to back side of axle flange.
Bolt heads could cause an Interference problem with new studs here?

drill new pattern through both flanges and install extended studs.

tig small areas between stud holes around outer edges to reduce heat effected zone.

or is this over thinking it?

[CBR Jeff]

Do you have wheels or do you still need to get them? You may be better using an off the shelf conversion spaces kit and running an offset wheel that takes the spacer into account (If you search the forum you will find answers about wheel offsets and what a standard wheel offset is).

Using something like this will have two advantages. It will work and maintain the integrity of the hub and it can be reversed if you want to go back to 4 stud.

Jeff

 

[Linton]

I believe spacers like those are not legal in australia

[CBR Jeff]

Haha @Linton I think you are correct but  I don’t think drilling holes in the hub or welding wheels would be seen as legal either. There is not much correct or legal about this conversation so far! At the end of the day making any changes to standard would need to be engineered to keep it “road worthy”. I believe using something like this could be engineered but I don’t think drilling holes in the flange would be.
I know what I would be doing. Either leave as is with 4 studs or getting 5 stud flanges. 
 

Jeff

[Robdog]

I’ll run spacers past the engineer, but Farley certain he wasn’t happy with this option.

it has created a predicament, I already had rbx rota’s, (yes these will not pass either, for the offset) on the car when the engineer first inspected some time ago. There was no mention of wheel stud pattern then, but recent discussions around brakes led to the problem at hand.
Ultimately my fault, thought stud pattern was a non issue, but power delivery is his concern.

so it would be useful to easily revert to 4 stud to save my wheels, but I fear I’ll be buying a new set. Hence looking for an acceptable cheaper option for the stock axles over billet items 

thanks very much for input 

[nizm0zed]

Did you ever have any success with this? Or any answer from the engineer?

I'm in the same position, wanting to set up 5 stud on my rear axles. Ideally I'd get some custom billet axles made up to handle the gobs of torque I have to deal with but its  looking stupidly expensive. Who did you get to weld up your old stubs and redrill them? anyone in Aus that is specialised in this for Datsuns?

Also, open question for anyone, I have read elsewhere that the flange face (and stub axle) is heat treated and hardened, that welding them ruins this hardening and can lead to failure of the studs close to the edges where the material is thin. Is this accurate? If the flange is welded up surely it wouldn't be too much of an issue to redo the heat treating on the stub axle?

Edited October 23, 2021 by nizm0zed

[Robdog]

Engineer wouldn’t have it any other way. I can understand this when they are putting their signature on the car. I ended up getting heavy duty Futofab axles.
Cost about $1500, but this also included VW adaptor to the old wolf creek racing cv’s,  also included a quick disconnect adapter to keep my cv lengths in check.
I went this way because the HD axles will give me some reassurance if I need to do a diff upgrade down the track.
Dave from Futofab was good to deal with.

[nizm0zed]

Ahh nice, Cheers for the quick reply.

I can't believe I hadn't come across these before in my recent searches, These will do perfectly for me.
the CV shafts will still be completely custom, But I was expecting that with my setup anyways.
Just bought myself a set of these.

http://www.futofab.com/index.php?page=shop.product_details&category_id=21&flypage=flypage_images.tpl&product_id=166&option=com_virtuemart&Itemid=81&vmcchk=1&Itemid=81