hi i did a search but i was too stupid and/or lazy to find the info i was looking for.. anyway i was wondering what EA-82 models you could get the LSD on. or if there's an EA81 LSD thats easily interchangable. i'm going to the junkyard this weekend and i'm hoping to find one (yeah i know--fat chance). but it would be good to know which ones to not even bother checking. all i know is to not check the FWD models .and i know the turbo's have a different ratio so i guess thats no good either. or can you just change the pinion and gear from the open diff i already have?

They were not avalible on EA81s in the US at all. They were an option on any EA82, so potentially any car could have one, but typically they were on RXs and Turbos and apparently sometimes on XT6s. Basically, check everything you can find.

All RXs, some turbos

Sorry for the noob question, but how does one id a limited slip rear?

 

Also, I take it that the front and rear need to have the same gear ratio, so how do I tell what I have?

 

Thanks!

 

- Freed

Visually inspect each dif.

The label is clearly marked.

Remember, somebody might have installed one, so check them all.

there's a BIG tag on the diff that says 3.70 LSD. Here's a pic of the one under my RX and its the same for all of them...

 

Rear diff tag

OK. that helps immensely. How do I know what ratio the front is then?

 

- Freed

all LSD are 3.7:1 do to the fact that they all come out of turbo cars. and i have herd word of a 3.9:1 in an XT6 but have never seen one. anyone that has a 3.9:1 LSD has taken the carrier out of a 3.7:1 diff and installed it into a 3.9:1 ring gear.

 

the gear ratio is writen on the Diff lable/sticker.

 

and the front ratio will be the same as the rear ratio, otherwise massave tire bind will accure

 

this is how i understand it, correct me if i am wrong

The ratio can be converted by installing the LSD kernal into any of the open diffs (look for info in the repair manual...I think it's there). EA82 diff will fit on the EA81 cars without any trouble. If the label is gone, or too greasy to want to read it, spin one rear wheel....if the other wheel turns in the same direction it's either an LSD or welded diff; if the other wheel turns in the opposite direction it's an open diff. Of course your yard will have to have the cars up in the air to do this. RXs have LSDs; it was an option on the turbos and GL-10 models; check all.....I recently pulled an LSD off an '85 BMW just for grins (I need to clean it up a bit before it goes on ebay).

So I guess (duh) that I can just check my diff and see if the new one is the same ratio. That would make sense wouldn't it. :-p

 

- Freed

Definitely make sure your new diff is the same ratio as the old one. A lot less grief if you do that.

So I guess (duh) that I can just check my diff and see if the new one is the same ratio. That would make sense wouldn't it. :-p

 

- Freed

Looks like I'm hosed. I've got a 3.90 in my hatch.

 

 

- Freed

to add my $.02 and make it a little more complex

 

like suberdave said :"all LSD's are 3.70:1 do to the fact that they all come out of turbo ea82 cars."

 

all turbo ea82 cars came with 3.70:1 gear ratios automatic or manual. All manual non turbo's are 3.90:1, some (maybe most?) auto non-turbo tranny's (3eat) are 3.70:1.

 

3.70:1 LSD's are always in RX's and almost always in fulltime 4wd turbo cars 87'+, either auto or maunal. LSD's can also be found in earlier, or part time 4wd turbo cars, but are rare in my experience.

 

Some fulltime 4wd XT-6's did get the 3.90:1 LSD, I've seen two...

 

EA 3.90:1 rear diffs will swap between gen's without any modification (except 76' and older with the u-joint style axles)

 

subaru rear lsd internals can be swapped between any diff realativly easily (@ usrm), for example I have a 3.90:1 lsd in my brat (swapped from an 87' rx) and a 4.11:1 lsd in my legacy (swapped from a 88' fulltime 4wd wagon)

 

there are also vlsd's in 92? SS legacy's that can be swapped around, but they are best for pavement use.

 

newer EJ turbo cars have LSD's as options, I don't know much about these. too much $$$$.

 

Phantom grip's can be installed in rear diff's relativly easily, front diff's not easy at all... they work very well from what I hear.

 

like ed rach said, spin one axle stub, if the other rotates in the same direction it's welded or an LSD.

 

Happy hunting

{snip}

subaru rear lsd internals can be swapped between any diff realativly easily (@ usrm), for example I have a 3.90:1 lsd in my brat (swapped from an 87' rx) and a 4.11:1 lsd in my legacy (swapped from a 88' fulltime 4wd wagon)

{snip}

 

Happy hunting

 

Sorry for the threadjacking. This seemed relevant enough to discuss here.

 

OK, so if I get my hands on a 3.70 LSD, I can take apart both it and my stock 3.90 and combine the parts in such a way as to turn mine into a 3.90 LSD? Am I understanding that correctly?

 

Without getting too far into the nitty-gritty, how would that work?

 

- Freed

Ok, I have a question for you diff gurus. Will the VLSD from a legacy turbo bolt into an ea81?

how much would i expect to pay for a 3.7 lsd at a junk yard?

freedster: this info is all on usrm and many other places, but here it is again:

 

crack em' both open at the rear plate, pull the stub axles off (torx socket) grind inner tabs off 3.90 case so it matches the 3.70 case, swap ring gear from 3.90 onto 3.70 guts, stuff lsd+ 3.90 ring gear into 3.90 case, put stubs on, seals, rear plate, fill with lsd gear oil additive and gear oil, 1.5 quarts? install, slide sideways even more often...

 

 

VLSD guts are swappable just like the 3.70 lsd's, but an ea81 isn't even going to have enough power to make the viscous syle lock up... I've heard you really have to have the wheels spinning before it locks. its a street application on a turbo 2.2, go get a 3.70 lsd they work in any situation.

 

JY $= $25-$350, pull it and tell em' it came off an old p.o.s. subaru

Wow. Thanks.

 

 

Sorry again for my noob-idge.

 

- Freed

When looking at JY EA82s, there is a fool proof way to tell which models came with LSD. It doesn't require you to look at the label on the diff or spin the tires. Just look very, very carefully at the inboard ends of the rear axle shafts. If there is nothing between them, that model car almost certainly came with a LSD differential.