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Mx5 diff how to id
chris_smith - 24/4/14 at 06:44 PM

Bought an engine and box today from mx5 1.8l, so I'm on the hunt for a diff, however i believe there are several variants and ratios- non LSD, VLSD, Torsen LSD etc etc, but does anyone know how to id them?

Many thanks

Chris

Smokey mow - 24/4/14 at 07:08 PM

Try ths link

http://www.miata.net/garage/diffguide/

philw - 24/4/14 at 07:41 PM

quote:
Originally posted by chris_smith
Bought an engine and box today from mx5 1.8l, so I'm on the hunt for a diff, however i believe there are several variants and ratios- non LSD, VLSD, Torsen LSD etc etc, but does anyone know how to id them?

Many thanks

Chris



I think, vlsd is 1.6 only, 1.8 eunos has either type 1 or 2 Torsen, and uk 1.8 variants have open diffs, as for identifying them the 1.6 has lugs on it somewhere(the miata link above will help with that) and the 1.8s if it's off the car then you need to have a look inside, as for ratios the rs ltd whch is rare has a 4.3:1 as for the rest I can't remember off the top of my head 4.1: rings a bell, go and have a look on mx5 nutz there is more info there

philw - 24/4/14 at 07:42 PM

There are also some you tube videos that may help

PorkChop - 27/4/14 at 09:28 AM

quote:
Originally posted by philw
quote:
Originally posted by chris_smith
Bought an engine and box today from mx5 1.8l, so I'm on the hunt for a diff, however i believe there are several variants and ratios- non LSD, VLSD, Torsen LSD etc etc, but does anyone know how to id them?

Many thanks

Chris



I think, vlsd is 1.6 only, 1.8 eunos has either type 1 or 2 Torsen, and uk 1.8 variants have open diffs, as for identifying them the 1.6 has lugs on it somewhere(the miata link above will help with that) and the 1.8s if it's off the car then you need to have a look inside, as for ratios the rs ltd whch is rare has a 4.3:1 as for the rest I can't remember off the top of my head 4.1: rings a bell, go and have a look on mx5 nutz there is more info there


I'm sorry, but there are a few inaccuracies there.

The Torsen LSD was a very popular option in Japan, but it wasn't a standard part. There are UK cars which came with Torsens from new.

What you must also remember that post 1993, only the European market continued with the (detuned) 1600. However, the larger 1800 diff, prop and shafts were fitted. The early 1600 diffs are 4.3:1. You can however, get 3.6, 3.9, 4.1 and 4.3:1 ratio 1800 diffs. The 4.1:1 is the most common, you can get a 3.6:1 Super Fuji diff reasonably easily (but are considered more fragile than a Torsen), but the rest are relatively rare.

The early 1600 diffs will all be bolt on shafts and will have stubs fitted to the diff. The very early 1800 size diffs also had bolt on shafts before moving over to 1 piece push-in jobbies in '94 or '95. The early 1600 diffs can be open or viscous LSD.

One thing to remember is that the prop, shafts and diff are not interchangable between the early smaller 1600 diff and the later 1800 diff assemblies. The driveshafts are different lengths and I believe a diffferent PCD. I also think it's a similar story for the prop, but I'm not 100%.

The easiest way to tell which diff you are looking at is to either have the rear cover off, or to look down through the driveshaft line and see what, if anything, is blocking your view to the other side of the diff.

HTH.

Slimy38 - 27/4/14 at 11:28 AM

quote:
Originally posted by PorkChop

One thing to remember is that the prop, shafts and diff are not interchangable between the early smaller 1600 diff and the later 1800 diff assemblies. The driveshafts are different lengths and I believe a diffferent PCD. I also think it's a similar story for the prop, but I'm not 100%.

The easiest way to tell which diff you are looking at is to either have the rear cover off, or to look down through the driveshaft line and see what, if anything, is blocking your view to the other side of the diff.

HTH.


Yep, the prop bolts are on a different PCD, the 1800 diff is also physically larger (about an inch or so).

thefreak - 28/4/14 at 10:39 AM

I've got a couple available if you're interested?
A standard open diff from a 1.8 for £50, or a Super Fuji diff for £15 as it's getting in my way now.

chris_smith - 28/4/14 at 11:48 AM

quote:
Originally posted by thefreak
I've got a couple available if you're interested?
A standard open diff from a 1.8 for £50, or a Super Fuji diff for £15 as it's getting in my way now.



you have U2U