Is there an easy visual way to identify a torsen?
 

As I'm starting to shop for a miata, i'm wondering if there is a simple way to identify a torsen from underneath. I did a search in this forum, and don't see anything. I did see that I can call mazda with a vin to check, but since i'll be looking at cars in person wondered if there was something simple from underneath.

If your search to find how to find a torsen didn't work, then your search to find a person to tell you how to find the post to find a torsen won't work either :). Search google, there's a good one on Miata.net I think.

I found this

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

but its still a little wishy washy. It seems like the damper has to be there for a torsen, but i'm not sure that the damper being there guarantees it being a torsen. Theres also a bit about the "ears" on the stub shafts, but they are mostly talking about 1.6s

Easiest way without taking anything apart?
Punch it mid corner and see if both wheels lock up and spin resulting in car getting sideways ridiculously easy.

Negative but close, go to a parking lot that has a big empty area. Turn the wheel at full lock which ever direction you are most comfortable doing donut/drifts. Punch it in first and let the tail kick out. If you can keep it kicked out while bliping the throttle on and off its a torsen. If the minute you let off the gas it snaps out of the donut its a tragic open diff. Dont look at tire marks as both can lay down 2 tire skids. I've probably used this to identify rear ends in 10-15 different miata's with out fail. If your not a good enough driver to cut a drift/donut or can't keep it hung out in a tight circle than you really don't need a torsen anyways so idk.

I think the bigger issue is how a seller will feel about me doing that on the test drive :D but thanks, it does make sense.

Your literaly going around 1 time. Its your $800 gamble.

Yeah, I guess if I am ready to buy a specific car, then I tell the owner exactly why i'm doing it. or offer him jacking up both rear wheels off the ground, and trying to spin both shafts in the same direction at the same time (which shouldn't work on a torsen)

Since when do used-car sellers not allow you to test drive the car by yourself? Hand over your keys to prove you aren't stealing it, and go hoon that bitch for a few minutes.

Yeah, especially in a 2 seater. Haven't shopped for a 2 seater in a looooooong time, so wasn't thinking about that :) I'll bring my wife along so theres no space for the seller ;)

I'm pretty sure that they both act the same when on a lift. The only visual inspection requires pulling an axel and looking inside for the bar.

Is there an easy visual way to identify a torsen?
 

No.

There's no way to visually tell without disassembling the diff or pulling a stub axle.

I thought if it had leather and a manual it was a Torsen.

If the car was orignially equipped with power mirrors, then it was originally equpped with a Torsen from the factory (if it was a '94 or later). The exception to this rule is the 1997 STO, which was Torsen-less.

15 years later, who the hell knows if a previous owner replaced a torsen with an open for any number of reasons:
Side impact at the rear axle tweaks diff gears which later self destructs due to misalignment.
Dude's friend has an open and wanted to swap him for $200 + a case of beer
Replaced with an open for Spec Miata classing rules

Plenty of non-leather cars had Torsens. A good indicator is cruise control - if it has cruise, it has a Torsen. No cruise, no Torsen. It's not perfect but it works for most years.

M.net has a good year-by-year breakdown of the packages and what cars came with torsens.

Since people like you started joyriding the fuck out of them and since people stopped trusting other people.
Good luck with that.
I've yet to see anyone around here let someone test drive their car alone unless its a complete and utter POS.

this is completely untrue.
unless you're talking about n/a's only in which case I'm not sure.

but there are tons and tons of nb's with power windows/mirrors and no torsen

Bore scope my friends works great open the filler plug and put the camera in and see. That how i knew i got a torsen on my last miata.

Remove the oil fill plug (upper) from the aluminum diff cover. Shine a very small flashlight into the hole, and look into it. Do you see worm gears? Then it's a Torsen.

Joe that's very close to what i said, so does that put me in with everyone?

Rich people who don't give a fuck about the money or the car they just want to get rid of the car will let you test drive a car alone. One of my buddies and I were looking for WRX's in the Northern VA area (lots of money up there) and of the 3 cars we looked at, all of them let us take the car out alone.

Better step off. I've never joyridden a used or new car. But maybe you just look untrustworthy -- I've never, ever been unable to test drive a potential purchase alone. Every single time, I've test driven it by myself or with just my wife along. One of the purchases, I asked the seller if I could take an extended (30+ minute) drive as it was an older Merc and I wanted a friend to look it over with me...he agreed and wouldn't even take my keys as security.

I'm not just talking about myself here. And I definitely don't look like some broke punk kid if that's what you were implying. My parents, both well over 50, went to test drive a prius, pulled up on a 2004 Lexus LS430 and the salesman still wouldn't let them take out a car alone. Same thing happened to my neighbor who purchased a focus. Same thing happened to my brother with a dodge ram he purchased.

Maybe its a CA thing though, to be honest. I've heard from many friends in other states that they just walk into a dealership, take the keys, and take a car for a test drive by themselves. Around here that's unheard of.
Same for anyone selling anything on craigslist or other classified ads.

I guess people are just WAY more trusting in other states?

Not implying anything. Just curious why I can always get a private test drive and you never can. I'm 28 with a scruffy beard and rogueishly handsome features.

Possibly.

you're 3 years older and thound just thuper:giggle::magna:

easiest way, dump the clutch like your launching it and have someone watch the rear tires.

:facepalm:
fail

i thought open diff didnt lock up and only one spins.


- http://www.youtube.com/watch?v=FPRvzgdNAW8




i also saw this

http://www.youtube.com/watch?v=YDOcWR4_Uhw

You can easily spin both with an open diff. If both tires have the same amount of traction in a straight line both will spin MOST of the time. With a torsen both will spin ALL of the time.
The big differences between the two are realized more in cornering and not straight line.

whipping the rear end around is a way to tell because the differential in traction between the two tires is significant enough that an Open diff is pretty much guaranteed to spin the inside tire.

Here's a theoretical test I was thinking about...would it work? Obviously, it's dangerous and you'd risk damaging the car if you actually tried it:

Jack one up rear corner, place jackstand so only one rear wheel is in the air. Start car, 1st gear, let clutch out slowly. If wheel in the air spins by itself, car has open diff. If both wheels spin (ie, car moves forward and falls off jackstand), car has LSD.

I'm surprized no one mentioned it but call your local dealer with the VIN# and they can tell you in 30 sec if it was equipped with a torsen. You can email MAZDA as well but that took forever when I did it a year ago. Attached is a chart I have for the NA's can't remember where I found it.

Only works on cars you know for a fact are unmodded.

No. When a wheel comes off the ground in a torsen it acts like an open. It needs SOME resistance on both wheels at all times.

Most cars you will see today will still be what they came from the factory with. If not generally the owner will know and try to use it as a selling point.

So, if your suspension setup was such that lifting the inside rear tire was possible, a Torsen wouldn't deliver power to the outside rear tire? I know that's an extreme case, but I'm curious.

There IS INDEED a way to make this test work...

Put it up on one jackstand so that only one rear wheel is barely off the ground, Make sure that corner is supported by the A-Arm and NOT by the Frame (So that when the car rolls off the jackstand / block of wood / etc., it doesnt cause damage to anything)

PARTIALLY APPLY THE HANDBRAKE (25-50%)

Then let out the clutch in first gear.

If the car lurches forward / pulls itself off the lift support, then it has a TORSEN

If the car remains in place, with the lifted wheel spinning against the handbrake friction, then it is open.

This is mostly correct - however, torque IS applied to the outside tire to the extent that the torsen attempts to compensate for the inertia of the lifted wheel as the lifted wheel accelerates.

It's not much, but it is definitively infinitely better than the response of an open differential with a lifted wheel which provides zero torque to the grounded wheel.

If Torsens didn't act like Opens when a wheel was off the ground, I suspect Clutch differentials would be nearly extinct.

True.

Learn sumpin' every day. Thanks!

That's why it's torque sensing, without any torque, it cant do shit.

I joy ride cars all the time. I've probably test drove 100+ cars since I was 16. 50% of the time I go by myself. Most recently I ripped ass in a 2011 Brembo Mustang GT. Literally ragged the piss out of it for 20min with the sales guy. I test them like I drive them, suck it.

One time I got paid $50 to thrash a 2010 g37s for 20 minutes, my glory days of professional driving are gone now though

One time I got paid with a stolen rug to hold onto some guns for a few days.

One time I got paid $200 for holding on to someone's dick for a few minutes.

One time I funneled whiskey in to my asshole, to get DAT buzzzzz

This one time at band camp....

http://www.youtube.com/watch?v=9pDTw...eature=related

Dont want to be the dumbest fuck on here,but if its LSD diff it usually tells you right next to the filler cap to use "LSD OIL ONLY",maybe its only on the RHD or euro spec ones we have direct from japan but just my :2cents: and most probably worth shit!:facepalm:

Ours doesn't say anything on em.

jack rear, spin tire. other will spin in opposite direction.

Ill post a pic later of it so you can see Mr Heff

This only works on open rear end.....maybe wrong,but there is another way of checking,if you jack it and is in some way able to secure one wheel slightly just to apply some kind of friction on it(tying it with strap or rope os some kind to the car,even putting the slightest hold on it with your hands and a rope so it does actually turn when LSD kicks is)[DONT BE A FUCK,and put a retard behind the gass peddle] and it is able to turn that wheel with more "drag" you have yourself a LSD just my :2cents:

I agree with the blip the throttle in mid donut approach. It works, but not exactly feasible during a test drive.

When I was buying mine, I drove casually for a bit, then, stopped with the right wheels off the pavement. There was actually a patch of gravel, so it was very convenient. I just spun the tires (not aggressively) and looked back to see if there was a mark on the pavement, too.
There was.
I repeated a few times, to verify.
I told the guy ı was listening for a noise.
Did not want to lose any bargaining points by revealing car had desirable components.

Oh, it has ABS, too. That was not brought up, either.