How to check if I have Torsen LSD

In article >,
pws > wrote:

> What's up, Lanny? Why would an automatic transmission and a torsen rear
> end not be used together?

For the definitive answer, you'll have to ask Mazda. But I suspect they
assumed that no one ordering an automatic would know or care about
performance equipment such as an LSD. Without the Torsen delete, the
auto tranny option would likely have cost twice as much, not an
appealing prospect for that market segment.

Rather simple. I looked in the oil fill plug hole when I changed the diff
oil to RedLine shortly after buying the car. The torsen centre unit looks
much different than the open unit. Open diffs have visible spider gears,
torsen diff does not.

"Chas Hurst" > wrote in message
. ..
>
> "Brian Minto" > wrote in message
> news:cCGGi.177137$rX4.158428@pd7urf2no...
>> My car a 1994 miata m-spec with an automatic transmission and power
>> everything. It DOES have a torsen differential and I can guarantee that
>> it is OEM.
>
> Interesting. How are you sure it has a torsen diff?
>
>
>> "Lanny Chambers" > wrote in message
>> ...
>>> In article . com>,
>>> "G. Mack" > wrote:
>>>
>>>> I have a 96 Miata. I've read on the web that this year's model comes
>>>> with either an open or Torsen differential.
>>>>
>>>> With my car on stands, when I spin the one rear wheel, the other wheel
>>>> will spin in the opposite direction. When I hold one of the wheels
>>>> tight, my son was not able to spin the wheel on the other side. Can
>>>> anyone conclude from this rather I have a Torsen LSD or not? If not,
>>>> is there any other test I can do short of pulling off a stub axle to
>>>> peek at the gears?
>>>
>>> From the miata.net Garage:
>>>
>>> (Q)How do you identify Torsen's without dissasembly?
>>>
>>> (A)The Torsen won't always turn both wheels when you turn the
>>> driveshaft, sometime if they are cold they will. One way is to take out
>>> the fill plug to see the Torsen gears which is hard to do because of the
>>> angle. Another way is to attempt to turn both half shafts in the same
>>> direction at the same time (tranny in neutral), can't be done with a
>>> Torsen. The foolproof way is to pull the stub axle on the type 1 or the
>>> drive axle on the type two. If you don't see a bar and can see directly
>>> thru the diff. it is a Torsen. If there is a bar, (spider gears) it's an
>>> open.
>>>
>>> Or you could phone Mazda with the VIN and they'll tell you how it came
>>> out of the factory. The only '96 Miatas without Torsens were base and
>>> power steering package models, plus all automatics.
>>
>>
>
>

"Brian Minto" > wrote in message
news:tKIHi.197869$rX4.10619@pd7urf2no...
> Rather simple. I looked in the oil fill plug hole when I changed the diff
> oil to RedLine shortly after buying the car. The torsen centre unit looks
> much different than the open unit. Open diffs have visible spider gears,
> torsen diff does not.

Thanks, I have wondered if the view thru the fill plug was conclusive. Did
you buy the car new?

No, I bought it used. It had been advertised a few times on the online
version of a BuySell newspaper here in Canada. I assumed that it was not
selling because of the automatic transmission. However, I knew that one of
the past SCCA autocross champions was a m-spec miata with an automatic
transmission, so I contacted the seller and got the VIN number from him.
When I contacted MazdaUSA about the vehicle (it was an American car), I
found that it was a rather rare m-spec car with the r-spec motor together
with the automatic transmission. I was told that there were less than 40
similar cars in North America. I flew to Vancouver, B.C. and bought the car
at the airport without even driving it first. It was in beautiful condition.
When I got it home, I set about changing all of the fluids to RedLine
products including the diff fluid, brake fluid, transmission fluid, power
steering fluid and the engine oil - just to be sure. I drive it year round -
dry, rain, snow or ice. Great little car - not actually fast but pretty
quick. I took a local miata racer for a ride in the car at the local race
track. He said that as a street car, my car would beat his race car even
though his car is gutted, prepped and runs on slicks. He was surprised at
how aggressive the automatic transmission could be driven. The extra power
from the r-spec motor certainly compensates for any loss due to the
automatic transmission.

"Chas Hurst" > wrote in message
. ..
>
> "Brian Minto" > wrote in message
> news:tKIHi.197869$rX4.10619@pd7urf2no...
>> Rather simple. I looked in the oil fill plug hole when I changed the diff
>> oil to RedLine shortly after buying the car. The torsen centre unit looks
>> much different than the open unit. Open diffs have visible spider gears,
>> torsen diff does not.
>
> Thanks, I have wondered if the view thru the fill plug was conclusive. Did
> you buy the car new?
>

On Wed, 19 Sep 2007 05:45:33 GMT, "Brian Minto" > wrote:

>....When I contacted MazdaUSA about the [94M]vehicle (it was an American car),
>I found that it was a rather rare m-spec car with the r-spec motor together
>with the automatic transmission.....The extra power
>from the r-spec motor certainly compensates for any loss due to the
>automatic transmission.

Did they give you any particulars of the r-spec engine?

-- Larry

"Brian Minto" > wrote in message
news:1I2Ii.4704$A55.2132@pd7urf2no...
> No, I bought it used. It had been advertised a few times on the online
> version of a BuySell newspaper here in Canada. I assumed that it was not
> selling because of the automatic transmission. However, I knew that one of
> the past SCCA autocross champions was a m-spec miata with an automatic
> transmission, so I contacted the seller and got the VIN number from him.
> When I contacted MazdaUSA about the vehicle (it was an American car), I
> found that it was a rather rare m-spec car with the r-spec motor together
> with the automatic transmission. I was told that there were less than 40
> similar cars in North America. I flew to Vancouver, B.C. and bought the
> car at the airport without even driving it first. It was in beautiful
> condition. When I got it home, I set about changing all of the fluids to
> RedLine products including the diff fluid, brake fluid, transmission
> fluid, power steering fluid and the engine oil - just to be sure. I drive
> it year round - dry, rain, snow or ice. Great little car - not actually
> fast but pretty quick. I took a local miata racer for a ride in the car at
> the local race track. He said that as a street car, my car would beat his
> race car even though his car is gutted, prepped and runs on slicks. He was
> surprised at how aggressive the automatic transmission could be driven.
> The extra power from the r-spec motor certainly compensates for any loss
> due to the automatic transmission.

I have never heard of an "R-Spec" motor. And from your cars' history there
is a possiblity that the torsen was swapped in by a previous owner.

> "Chas Hurst" > wrote in message
> . ..
>>
>> "Brian Minto" > wrote in message
>> news:tKIHi.197869$rX4.10619@pd7urf2no...
>>> Rather simple. I looked in the oil fill plug hole when I changed the
>>> diff oil to RedLine shortly after buying the car. The torsen centre unit
>>> looks much different than the open unit. Open diffs have visible spider
>>> gears, torsen diff does not.
>>
>> Thanks, I have wondered if the view thru the fill plug was conclusive.
>> Did you buy the car new?
>>
>
>

On Wed, 19 Sep 2007 11:10:12 -0400, "Chas Hurst" > wrote:

>> The extra power from the r-spec motor certainly compensates for any loss
>> due to the automatic transmission.
>
>I have never heard of an "R-Spec" motor. And from your cars' history there
>is a possiblity that the torsen was swapped in by a previous owner.

Neither have I, which is why I asked. I have been told by a couple of Mazda
people that the engines in Rs were specially selected, but taken from normal
production.

-- Larry

"pltrgyst" > wrote in message
...
> On Wed, 19 Sep 2007 11:10:12 -0400, "Chas Hurst" >
> wrote:
>
>>> The extra power from the r-spec motor certainly compensates for any loss
>>> due to the automatic transmission.
>>
>>I have never heard of an "R-Spec" motor. And from your cars' history there
>>is a possiblity that the torsen was swapped in by a previous owner.
>
> Neither have I, which is why I asked. I have been told by a couple of
> Mazda
> people that the engines in Rs were specially selected, but taken from
> normal
> production.
>
> -- Larry

I've heard the same story about 10AE engines. Miata engines aren't started
until the completed car drives out of the factory.