yeah TRX wheels fit great with this diff, but the other wheels only just fit in the guards
so i can just run spacers on the rear whenever i run the TRX rims

oh and measured the diff, 1330ish mm with the discs on so the 1317mm must have been without discs

the drilled r31 rotors (ones in the pic)? they were on the diff when i got them and i drilled them myself (have a nice pattern for doing it)
they are just siting around doing nothing at the moment

i now have the r32 brakes with a heaps bigger

I have a quick question for you.

Do you remove the tubes out of the centre housing by drilling out the welds and pressing out or do you just cut the necessary amount off the axle tube and machine up a section that fits neatly inside the tube and weld it all back up?
If you remove the tubes how hard is this to do?
Also do you know anyone who can shorten the long axle in the Sydney area?

Any advice would be welcome as I am about to shorten one. I have all the gear and a lathe just need to know the easiest way.

Thanks
Shayne

yeah drill out the welds, i drilled then diegrinded as i could only drill so big

then you need a hydrulic ram that fits inside the axle tubes to press them out, need to be able to handle about 20 tonne

then once they are out you cut how ever much off

then getting them back in is also fun, need a big press and i mean BIG, have to press one tube in at a time and it took about 16 tonne of pressure to get mine in all the way
also my press was only just big enough to fit the diff in as the platform will only go down so far
once they are in weld up the holes where it was originally welded....and your done

not the most fun job in the world when you do it the first time, and if you give up half way i dont think any diff shop will want to finish it

most engineering places should be able to shorten axles, or just ask the closest diff shop who they take their axles to

Thanks for that.

I might try just cutting the tube and machining a sleeve that will fit inside and chop a section out of the tube and butt weld the whole thing back together. I think this method should work fine also. I have access to big presses but probably more chance of stuffing it up. I was hoping that the tubes would come out easy once the welds were gone.

Thanks for your help

yeah i was hoping it would be easy too

only thing with cutting and welding is you might need to get it straightened

Hey SG,

I've worked on 3 BW78 cutdowns. I've never heard of anyone removing the tubes from the centre.. sounds like far too much work. A sleave on the inside or outside if fine. Even an expertly mig/tig weld will hold up with no sleave, so long as the mating surfaces are pretty square..

Thats all there doing to my set up. Just cutting and re-welding. They set it up in a jig to keep things square.

i pull them out and press them back in

for me it was easier than getting the thing straightened

Thanks for the advice. I will give it a go and take some photos etc to post up. I will check to see how straight it ends up as well. I will ask some of the welding engineers at work what they think also.

should end up pretty damn straight, but then they say you can bend diff housings by just running a weld across them