mx5cartalk.com

Guys,
Firstly, I've seen conflicting specs regarding the Diff ratio on a 1999 10AE.
Does anyone know for sure that it's definitely a 3.909 (or is it be possible that it could be a 3.636, which I've seen written on a well known website) ??

Secondly, I want to swap out my existing 1999 10AE 6sp with 3.909 LSD, with a 1994 Clubman 5sp 4.1 LSD.

I already have the 1994 Diff/Tail Shaft/Half shafts.

The difference between them is:
The 1999 has the Single Half shafts (spline both ends).
The 1994 has the two piece half shafts (flanged/Spline ends)

From Beavis' very informative video, he indicates that it's a compatible swap out...provided that the Tail Shaft/Half shafts go with the diff.

The problem is:
The 1999 Outer CV stub axle, includes the ABS ring.
The 1994 Outer CV stub axle, does not have the ABS ring....which I need.

So I would hope to take the Outer CV Stub Axle from the 1999 and put them on the 1994....job done.
Does anyone know for sure, if I can just take the 1999 Outer CV stub axle and fit it to the 1994 Outer CV stub axle??

I know the other option is replace the Ring Gear....but I think the above is the simplest option.

Again....I would appreciate your comments.
Cheers,
Jim

I did see this after my post.
https://www.miataturbo.net/suspension-b ... 8-a-63614/

It looks like the same issue.
I assume that he went down that path, because he found that it wasn't a straight swap of the outer CV stub axle.
It requires some lathe work (and a lathe).

Any other comments would be appreciated.
Jim

First up, which 'well known website'? If Murican (or any other O/S), ADM and USDM/wherever can have different specs, so that might not be much of a guide. Best and most certain way is to measure the ratio by turning the prop shaft and counting the revs of the wheel. You might get a result looking at the speedo gearing on the gearbox, don't they come in different colours for each ratio?

Unless you get someone who has done it themselves, I'd be nervous about swapping the inners. The possibility of a design change is too great, given the number of years between the NA design date and the NB. I'd cut to the chase and do the ring gear swap if were my car. Of course you can try the swap and if it doesn't work/is too problematic, you can still do the CWP swap.

OTOH, do it for science, and the whole community can benefit from knowing the answer

Ah well, looks like the 'for science' angle has been done.

Still, lets not get ahead of ourselves, maybe you don't need to do any swap ... do the work to identify you CWP ratio and you will know if anything more is required.

pdsman53 wrote:seen conflicting specs regarding the diff ratio on a 1999 10AE. Does anyone know for sure that it's definitely a 3.909 or is it possible that it could be a 3.636?

Mazda Australia spec sheet below states 3.636, & Slowpoke on here confirmed a 3.636 CWP came out of his ADM 10AE (which he bought in 2000 with 3k kms). The 3.636 CWP went into his shed for storage, & he later did a count to confirm. However, USDM 10AE did get the 3.909 CWP.

Hi.
The abs rings are tap on fit and easy to remove . Check the diameters are the same and if so it becomes easy.