S4 & S5 Differentials Interchangable?
 

anybody know if they're Interchangable?

axles, housings, ring and pinion?

yeah, as long as you stay N/A or T2, and don't try to swap gearing (for example a 3.9 pinion won't work with a 4.1 gear, and a T2 diff won't fit into a NA housing).

umm but... some models have the same gearing and LSD type....

yeah, between the T2 and the N?A some models have the same gearing, but the diff is a different size. Same with the LSD.

ok...so all non turbo S4 and S5 are interchangable but only T2 LSD's and gearings are interchangable S4 and S5?

Sort of...
Maybe this will help

N/A 4.1 diffs are interchangeable only with any N/A 4.1 diff

N/A 3.9 diffs are interchangeable only with any N/A 3.9 diff

T2 4.1 diffs are interchangeable only with any T2 4.1 diff.

Series does not matter as long as it is a FC... only the diff size and gearing matters.

i see...

why are they not interchangable? seems kind of stupid for mazda to produce so many different differentials. usually its the same differential with different gearing.

different diff size?
different holes for ring and pinion on diff?

also is the T2 diff larger than na ones?

You could swap gear sets between N/A models, but you need to swap gear and pinion.

so how do people change their NA's differential to a turbo differential

They replace the entire housing and half shafts

When Mark refers to the differential, he is only refering to this, no?

http://www.mazdatrix.com/pictures/g7-3.jpg

He isn't talking about the carrier and the case, which make up the entire assembly.

Mazdatrix also has a page on swapping diffs:

http://www.mazdatrix.com/g5.htm

sweeet...thanks for the info mark