Choosing rear stub axles for diff upgrade

[CowsWithGuns]

Hello friends,

The other day I snapped an axle and have been thinking about upgrading diffs. Spent a few hours trawling through and have settled on upgrading to a nismo 1.5 way for my daily r34 gtt (I have no hopes for finding a nice helical from an s15 or late r34 any time soon, and if I'm gonna spend 1k+ on a centre it might as well be the 'best' one). Naturally I could go with 38420-RSS15-B5, the default for the r34 gtt, however; since my axle has snapped and I haven't sourced a replacement yet (seeing them $600+ second hand - gross!), I was wondering if theres a particular stub axle with readily available/cheap axles from newer nissans (e.g. 350Z) that are as strong or stronger than the stock r34 ones.

This option has broadly complicated things as I wouldn't know where to begin with determining what shafts have what bolt patterns/lengths to fit my car, so I was hoping someone has some pre-existing knowledge to share.

While I'm at it, it's a mystery my axle broke spontaneously (admittedly during a pull). The road was wet, and I only only push 230kw at the moment - any reasons why it might just give up and die like that with my relatively weak car and poor traction conditions?

[robbo_rb180]

What bolt axle do you have 2x3 or 5x1? 5x1 is the better design.
How low is the car and what angle are the axles at? 
What was the condition of the axle? plenty of people running the standard gear with a lot of power & semi slicks.

Best upgrade is the 350z but will require a diff swap and I think a hub swap to suit the outer splines similiar to gtr.

 

[CowsWithGuns]

I've got the 5x1. The car is lowered a fair bit - I see your point here. No idea, the cars seen a lot of action from the prior owners and lately from me so I guess it's a given eventually it wears out.

Regarding the 350z setup. I'm not down to go to the ~3.5 ratios the 350z runs. Currently I'm stock at 4.11, lowest I'd consider is 3.8. Getting a diff setup between 3.8 and 4.1 that accepts 350z axles and has a fully functional LSD (helical or mech) would be the dream. I have more research to do, thanks for your input.

[CowsWithGuns]

Couldn't edit my post, sharing my discovery here:

https://www.leesonengineering.com.au/blog/r200-350zgtr5x1-stub-conversion/

This mob will convert your stubs to accept both 5x1 and 6x1 patterns. With this option available down the track, I'm going to go with the recommended nismo LSD for my car which will come with 5x1. I was considering trying to get something with 6x1 stubs to 'future proof' my drivetrain but couldn't figure out whether the diff centres in those kits would be different or not, risking fitment issues with my diff housing.

[Duncan]

very interesting service. I wonder how/if they balance it afterwards as the new flange is not symetrical

[GTSBoy]

Balance almost certainly not important at that mass, diameter and location in the drivetrain. Balanced probably better, sure, but I'd be willing to bet the resulting vibrations from being left as is would be undetectable without reasonably precise gear.

Once thing I don't love is the vert close proximity of 2 of the holes. Not a lot of meat there. I know the flange to flange contact is still mostly there, but there would be a reasonable section of the axle's flange that overlaps the really close stub flange's hole - right where you would want to be transferring load. Again, probably about as important as the balance issue, but it still irks me.

[WR33KD]

There are aftermarket axles you can buy called dmax, I run them do a quick google of them and see if they fit what you need