Diff compatibility issue...
 

Well the 2nd dispaintment of the day (after the gearbox issue mentioned in another thread) is that the 3.9 diff I got is different to the 94 (ish) rear subframe, diff, axles, bigger brakes etc I also recently just purchased.

The older diff has axles that bolt on to half shafts while the 3.9 ratio 98-99 diff has axles that go in to the diff housing directly.

Aaaaaghhhhh. I have done so much research and not once did I see this, then reading the Haynes manual on diff removal it specifically mentions the two types....HOW did I miss this. :facepalm: :noob:

Having spent truckloads of money recently on this jigsaw puzzle I welcome any advice for the cheapest, quickest solution.....?

Uhhh...use your one piece axles in the 3.9? It's not like they don't fit...or use your 2 piece axles in the 3.9?
I don't see how this is a problem.

Right so you are confirming that I should just remove the 2 piece axles and they will install in to the 3.9.... correct?

Sure. My torsen came with stubs and I popped them out and used 1 piece axles.

yeah or use your 94 axles.
the only real difference are axle nuts. NB cars have bigger nuts.

Cool thanks guys.

Advantages, disadvantages of 1 piece v 2 piece for track day sort of work...?
or effectively no difference..?

None I have seen.

2 piece axles are easier to get in/out when you don't have the whole rear end apart. The only time you would have to worry about the axle/diff mating is if you're switching from any 1.6/1.8/Mazdaspeed to another of those 3.