NA diff help

[devolutio]

I guess from there you should put oil in and start saving for an upgrade. is it a 1.6? good chance to justify the upgrade to 1.8.

[project.r.racing]

yeah all you can do is buy a new diff.

[Guran]

I think you'll find that your diff housing is alloy if it's stock. Tested mine with a magnet and no sticky, so it's definitely not ferritic.

[Steampunk]

so does that mean i can get a 1.8 diff and dont need to get an alloy housing...coz i have one?

Yes, and no.

Yes, you can buy the diff "centre", which is the actual differential gears themselves and it will fit your housing.
No, meaning it won't be a straight bolt-on deal.
It's hard enough taking the diff housing apart, and the general concensus is that you need a professional transmission shop to install the centre properly.

Best to buy a whole diff, including housing, then it is a relatively straightforward bolt-on deal.

[91mx5]

Hi Andy,

Photo looks like standard open NA6 diff to me. "open" meaning non- LSD. It looks like the drive shafts bolt onto short shafts on the diff assy, which is the NA6 configuration. Later versions have splined shafts which go straight into the side of the diff. I replaced a similar unit in my 91 NA because of noise (which turned out to be gearbox, but that's another story!) It's an easy job, took me a little over 3 hours. You need to drop the tailshaft, unbolt the drive shafts, unbolt the PPF (aluminium frame from gearbox to diff) and separate the rear hubs from the upper A arms (1 x bolt either side) to allow it to drop and
release drive shafts. Think you have to remove rear muffler from rear of cat converter also. Support diff on jack, (so it doesn't fall out and kill you!) then unbolt from car. It's all pretty obvious when you get under and have a look. You'll need stands to support the car as both back wheels will be off when doing this job. I bought a good used assy from Richard at MX5 plus for $440. It was from a sub 100K Japanese car. Richard gets a diff guy to remove the centre from the housing and check them before selling ( and refits of couse). He can offer various upgrades and know all the combination of bits you need, ie tailshaft length is different on NA8, and driveshafts are different etc etc. MX5 Plus also have a great workshop if you don't want to do it yourself. I had the gearbox work done there and was very impressed.

Good luck,

Allan

[manga_blue]

If you're not racing and you're not highly modified then another standard diff may well be good enough for you. You'd probably find a complete assembly for next to nothing from another forumite who is racing or is turboed. Then, as 91mx5 said, you and a mate can bolt it in in a few hours. On the other hand your old one might last for months with decent oil in it.