[astro]

I recently got the torsen LSD on my 99' miata replaced after it broke. It broke after I was rear ended by a truck.
My mechanic says he replaced it with another torsen from a 2001 model.
But the thing is, the replaced differential feels A LOT different than the one I had before. It's really hard to kick the rear out now. Before I could easily do a power oversteer. Now with the replaced differential, I don't even think my car is capable of doing donuts.

Did I get burned and got an open diff? If not, what could be causing it to handle so much differently?

 

[jdmeg2]

jack the rear of the car up, put it on jack stands. put the tranmission in neutral. get under the car and turn the drive shaft, if one wheel goes forward, and the other goes like its in reverse, then it should not be an lsd.

you can also spin one wheel and if the other goes in the same direction then your good, but that might only be for clutch type lsd's

 

[astro]

can anyone confirm this?
I heard the torsen behaves as an open in this respect

 

[Max_Power]

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

 

[sideshow]

that only helps for 1.6.. you need to pull an axle and look for the pin.

 

[DRFT MX5]

The reason it feels different is the 2001's Torsen was offered in the LS model... the LS model has a 6 speed gear box. If you had a 5 speed 99 Torsen before you had 4.39 rear gears... the 2001's 6 speed is something like 3.96. It could be something else, but that would be my first guess.

 

[freedomgli]

http://www.miata.net/garage/vlsd.html

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.

No bar=Torsen

Bar = open or RX-7 clutch type

 

[astro]

Meh, so I'll need to take the housing apart to tell?

 

[freedomgli]

No, I think all you need to do is pull the axle so you can see inside with a flash light.

 

[Sriracha]

How about a quick clutch kick in an open lot?

 

[Max_Power]

I recently got the torsen LSD on my 99' miata replaced after it broke. It broke after I was rear ended by a truck.
My mechanic says he replaced it with another torsen from a 2001 model.
But the thing is, the replaced differential feels A LOT different than the one I had before. It's really hard to kick the rear out now. Before I could easily do a power oversteer. Now with the replaced differential, I don't even think my car is capable of doing donuts.

Did I get burned and got an open diff? If not, what could be causing it to handle so much differently?

My friend Dave has a red 91 (NO LSD) and we been together in 3-4 auto-x events (I was running with his car).

There was a huge difference between my car (1.8 '94) and his car and while I drift my car every day... with his car:
->I couldn't get the tail out
->when the car was oversteering I couldn't control it #-o

So from you description I believe that you got an non LSD #-o
You better check it now, before it's too late!

I would say go ahead and put a skiny "emergency tire in one wheel, if you don't mind put some soap around it get it wet.
Then try to start agresively, you should be able to feel what's going on

 

[astro]

Thanks for the replies.
How do I pull the drive axle? Is it hard? Will I need to get it on a car lift?

 

[astro]

Well I still haven't got this done.
I'm not too handy with cars. How do I pull the drive axle to check to see if the bar is there?

 

[Braineack]

just do a quick burnout and have a buddy watch to see if both wheels spin. thats the easiest thing you can do.

But if you went from say 4.30 to 3.93 you won't have as much low gearing as before to maybe kick the rear out.

 

[vicious-s]

Well I still haven't got this done.
I'm not too handy with cars. How do I pull the drive axle to check to see if the bar is there?

you should start by taking the bolts out that connect the hub to the rear lower control arm. undo the giant nut that keeps the axle in the hub. pull the hub away from the car and get the axle out of the hub itself.

there are c-clips that hold the axle on. its nothing but brute force to get them out of the diff. get two pry bars, and wedge them so you are pulling the axle out of the diff. it will pop out eventually.

everything is pretty simple and straight forward. put everything back the way you found it. the axle just pops right back in. you may need a rubber mallet or something to help "persuade" it back to its home.

the only other thing i can think of, is if your original torsen was a type 1 (locking mainly on acceleration), and it was replaced with a type 2 (locking mainly on deceleration). the only way to find out is to see for yourself!

 

[astro]

Wow that sounds hard.. especially if I don't have a lift.

Is there an easier way?

 

[astro]

just do a quick burnout and have a buddy watch to see if both wheels spin. thats the easiest thing you can do.

But if you went from say 4.30 to 3.93 you won't have as much low gearing as before to maybe kick the rear out.

I heard the torsen acts as in open in that situation. Do you know?

 

[Max_Power]

Wow that sounds hard.. especially if I don't have a lift.

Is there an easier way?

Look from you description it looks like you got a non LSD.
Go to the mechanic and tell him...
"You know something, I started aggressively on the wet and one of the wheels was spinning while I stayed in the same spot, I think you accidentally :mrgreen: put an non LSD diff to my car...
I WANT MY MONEY BACK"
You see if you do the above, 99% of the mechanics will check it and if it is an LSD they will tell you come and see for yourself 8)
You paid so much money and you are not satisfied go back and tell him the above and ask for proof or refund!
Or tell him maybe this LSD is not in good condition...
LET HIM DO THE DIRTY WORK FOR YOU!

 

[superboosted]

Why did you have the diff replaced?

Usually in a rear end collision you will only need the housing being as they have a notch that lets them break on the passenger side,as to save the driver from the PPF catapult.

Sounds to me like you did'nt need a diff,just a housing[$125-$150].

There is also another stock type lsd that could have been swapped,it is the togegi fuji[sp]and it is a clutch type,very different than a torsen.

I have seen these in 02'-up.