I just bought my first Soob about 2 weeks ago. Looking at the rear diff it has a tag that list the gearing (3.9). How do I tell if it is LSD? Did they make LSD front and back or only back?

--GoatBoy--

You don't have an LSD - uness it's been swapped in.

 

Jack up the rear, and turn a wheel - if it turns the same way on the other side, it's an LSD.

 

GD

The 3.90 is a pretty good sign that you do not have a LSD. For the most part, from the factory, Subaru with LSD's had a 3.70 ratio, here is what the label on a LSD looks like.

 

It is larger then the non-LSD tag.

Thanks Guys! So what is involved in swapping in an LSD? The whole diff or just the inards? Do I have to go to a 3.7 gear ratio to get LSD? What donor cars should I look for? Or is there aftermarket LSD?

theres a writeup in the online repair manual. You will likely only find 3.7 lsds, You can then do some grinding to the 3.7 case and put in a 3.9 r&p.

Now that you mention it I remember reading that article awhile ago. Forgot all about it until you just mentioned it. Thanks!

the other option is to keep the 3.7 lsd as is, and put in a tranny w/ a 3.7 drive ratio. you might consider that to get a better tranny in there. the 5 speed dual ranges are 3.7.

King, might note that only the turbo 5sp's are 3.70 ratio. Not a better tranny for anything but highway driving. For rally or offroad the 3.90 is the prefered tranny.

The 5 speed dual ranges are 3.9, except for the RX tranny, which is full time 4WD, and only has a 1.2 ratio low gear......

 

GD

What is VLSD? I am unfamiliar with that one. My tranny is a Dual Range 5 speed. What years and models did that 3.9 VLSD come on?

--GoatBoy--

Isn't it the XT6 that had this?

 

Apparently according to some I've talked to, they aren't much good for off-road. I think Zapar had one in one of his off-road rigs for a while, and reported they suck - at least for that purpose.

 

GD

i was told vlsds came on legacy torbos

legacy would be a 4.11 rear diff I think..... at least the ones I've seen are.

 

The 3.9 VLSD is some sort of late 80's option I think... XT6 maybe? I'm not sure tho.

 

GD

The viscous LSD is the rear diff for AWD cars. Started with the Legacy I believe. They came in 3.90, 4.11, 4.44. The VLSD is more of a speed type(fluid) rather than a LSD which is a clutch type and is more of an off the line type.

So for off-road traction I would want the LSD not VLSD, right? And what kind of donor car should I be looking for?

Found a great set of explanations:

 

http://auto.howstuffworks.com/differential6.htm

 

All you could want to know! I really wanted more info, so I searched around.....

 

GD

Sweet! Thanks GD!

Donor cars:

 

RX's had em in the late 80's.

late 80's GL-10 full-time 4WD Turbo's had em stock I think.

They were an *option* tho, so check under every EA82 you see. Look for that big sticker on there or turn the wheels if you can and see if the other side turns the same way.....

 

In my experience some yards don't know from LSD versus open, so at those you get em cheap. If they are savvy, you'll end up paying up for then. I know of one yard that pulls them for the datsun guys. They want $150 a peice, and you of course will not find em in the yard there....

 

Also have had yards not allow me to pull them myself, saying they are too heavy, and that they would have to do it for me. Rubbish I say - if you can't lift 50 lbs of diff, then you shouldn't be out in a JY at all.

 

GD

Amen to that GD. I am used to big Chevy trucks and SUVs with there gigantic parts. These little ol soobs are toy sized in comparison.

What are your favorite yards around the PDX area??

Not all RX has AWD, some are 4WD. -> I think after 1988 are AWD?

Cheers

Tristan

The damascus and foster ave. U-Pull-It's are decent. Look at their map.... the ones farthest from the city center have more old stuff, and are less picked. I personally do more "shopping" durring the winter - people don't like the weather, and cars stop running because of it, so they don't get so badly picked this time of the year. Middle of the summer is the worst - people always scavenging the yards cause of the sunny weather.

 

Forget about the Salem U-Pull-It. They just reorganized the yard, and last time I was there, there wasn't anything old to be seen. Could always change I suppose - too far to drive for nothing tho.

 

Some of the cheap yards down on columbia and stuff are alright.... some scary people hang out in those yards tho - hell, even the people at the front desk are looking like vultures. Wear really ratty clothes and drive your worst looking car cause they will price gouge you if you look like you can afford it. The yards are dirty and un-organized. You have to walk all over the place in seriously deep muck to find the cars..... really annoying. Sometimes you can gets steals at these yards tho cause they are willing to bargain. At the U-Pull-It's, there's no bargaining - they go off a price list, and if you don't like the price, then you just don't buy it.

 

At any rate - I'm not giving up ALL my secrets. You can look around - check the phone book - drive down columbia and look at the signs - stop when you see one and ask what they got - if they do it U-pull-it style or what. Some don't.

 

GD

Alpine Raven, NO RX had AWD, in 1987 the had what is called Fulltime 4WD, but that is not that same as AWD. There is an open diff in the Fulltime 4WD trannys that is lockable, in the AWD trannys there is a viscous limited slip center diff in the tranny.

 

Goatboy, the swap is easy, I've done several myself, and have one to do for a friend soon. But you only swap the center section, you keep the ring and pinion from the 3.90. If you were a little closer, I'd love to show you how, but it's a 3 hour drive from Portland to my place.

theres a scrap yard about 2 miles from my house.. they have a fulltime 4wd XT6 sittin out there.. i asked about the rear diff.. they have it for $200....

 

not sure what ratio was in the xt6 tho, and of course the guy there had no clue..

 

he also doesn't even know he has a RX 3dr sittin in his 3 rows of older soobs...