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I've searched Google and various forums but can't seem to get a definitive answer on where the 4.3:1 final drive 7" diffs come from.

Some say 99+ 5 speed NBs *all* have them. Some say all AUDM NBs were 4.1 or 3.9. Some say they only come on JDM special editions.

I'm basically asking if it's worth checking at wreckers for a 4.3 or if I have to bite the bullet and buy one from MX5 Plus/Mania when they're available because they only come from exotic imports.

Would be happy to hear where people are finding them.

I believe they were fitted to AUDM 1.8L cars with automatic gearboxes. Obviously there were never many of those sold, so there aren't too many of the diffs floating around.

Interesting - That's something to go on.

Now as far as auto diffs go - they don't come with a damper on the input shaft.....

Running one in a manual car yes/no?

I picked up a4.3 and yes it has a damper on it. Dont know what it came out of though..

Skyntara wrote:Interesting - That's something to go on.

Now as far as auto diffs go - they don't come with a damper on the input shaft.....

Running one in a manual car yes/no?

It'll be fine.

NA8 didn't have a damper.

So can anyone else confirm the only 4.3 ratio diffs on AUDM cars were from auto NBs?

Can confirm they weren't on audm manuals.

PaulF wrote:I believe they were fitted to AUDM 1.8L cars with automatic gearboxes. Obviously there were never many of those sold, so there aren't too many of the diffs floating around.

Confirm. I know someone who does low volume custom cars and sources diffs from autos.

I think USADM is the same, so if you really want one look there.

I was told they also come from a rather obscure delivery van like a JDM Bongo.

Steampunk wrote:I was told they also come from a rather obscure delivery van like a JDM Bongo.

Also, maybe (big maybe) the Aussie delivered E2200 van or somehting.


I think the Kia Sportage crown/pinion fits as well, and is a 4.7 from memory.


Look them up though, it's been a while.

The Kia sportage is a 4.77 and from experience now, I would keep away from them if I was you.

The 4.3's weren't ever available in any Aus delivered car, 1800cc MX5, Mazda Van or anything. They were a Japanese ratio and are still high in demand for the secondhand market over there. Getting hold of them reasonably priced is pretty hard. Brand new from Mazda they are somewhere between $700 and $800 on a 6-8 week delivery.

I have been trying to find out what models they were released in for years but still only know of a couple of MX5 models and then there is still no real dead cert that it will be what it should be. I have had a few only to find a 4.1 or 3.9 in them.

This is the cheaper of two on ebay
http://www.ebay.com.au/itm/Mazda-MX5-NA ... 41730279e9

Some good info - thanks everyone.

The above diff is actually from Automotive plus as mentioned in the original post. In fact all the 4.3s up on ebay are. There are apparently 2 of each, open and torsen. I could buy the open and split it, get a torsen centre fitted but by the time you do that you're replacing bearings and seals and probably spending the same if not more.

I guess it's time to bite the bullet, pay the piper and order from Automotive plus for a couple of hundred more than a 4.1 I'm sure my poor little 1.6l will appreciate it.

All 1.6L cars came with 4.3 ratio diff, this includes all NA6 and the NB6 from Japan and Europe. The last of the NA8s also had 4.3 ratio to replace the regular 4.1 ratio, 1997 NA8.

All manual NA8 and NB diffs had the dampener. All automatic cars and NA6 had no dampener.

So to answer your question, 4.3 ratio 7" diffs came from the late model NA8 and the NB6.

I will be running a 4.778 ratio with my ITB/Cam'd NB6 engine.

So I ended up just buying one from Automotive Plus.

Seemed like the easiest way. At least I know it will hold its value being so rare.