Ok so I need some info about what is out there in the drive train stuff. I have a 87 gl turbo wagon with the push button 4x4 right now and was wanting to go to a DR tranny sometime in the future. But I read somewhere that there was some AWD DR with a center dif lock. What did these come in? What would you expect to pay for one in decent shape? And how are there reliability, I know the later legacys are good for thousands and thousands of miles with out any headaches just was wondering of they put the same effort in the older ones.

 

Thanks

I pulled a d/r full-time 4wd with center diff lock out of an RX (I think it was an 89, but not sure) at pick-n-pull for about $150.

 

I also picked up the limited-slip rear diff while I was there.

is your car turbo? - look at the rear diff, there will be a ratio on a tag on the back of it - if it is 3.7:1 (turbo), then the dual-range full-time 4WD will bolt right in (mind you it is NOT AWD - you have to manually lock the center diff) and you will notice no difference in drive ratios - you will have to swap the diff for it to work if yours is a 3.9, or if you want to go with a 4WD dual range tranny

however, if it is 3.9:1, you will find that the 4wd d/r tranny will bolt in

 

the 3.9 ratios are better for grunt work, and the 4WD tranny has a lower low range thant the Full-Time-4WD tranny - the 4WD tranny also has a higher final drive when in top gear, so you will cruise better one the highway with it versus the 4WD tranny

 

of course, you will have to swap linkage, and consol pieces, but it isnt that hard to do

is your car turbo? - look at the rear diff, there will be a ratio on a tag on the back of it - if it is 3.7:1 (turbo), then the dual-range full-time 4WD will bolt right in (mind you it is NOT AWD - you have to manually lock the center diff)

 

Actually, it is AWD when the center diff is not locked. That means power is transmitted (in theory) through the differentials to all four wheels. The unfortunate thing about this setup is that with three non-LSD differentials, the wheel with the MOST slip will get all of the power being transmitted. Locking in the center diff puts the car into 4WD mode, in that power is being transmitted through a locked diff to both front and rear. In that case, the front wheel with the most slip AND the rear wheel with the most slip will turn. If you add a rear LSD, both rear wheels and the front wheel with the most slip will receive power, giving you the best traction available on any stock EA series car.

 

Having said that, locking the center diff is like locking in the 4WD in a pushbutton or d/r car; it should only be done in limited traction or off road conditions, as torque bind will occur on dry pavement.

true - but I was refering to the different terminology Subaru uses - "Subaru AWD" indicated a system that can porportion itself out, IE it is more complex than the regular open center differntial (like what you are looking at) - and it uses ATF for the gearcase (seperate diff oil) - the Full-Time 4WD is the system you would be looking at

 

it is true about being careful when you use the diff lock - and I have seen some members complain about the diff lock mechanism not being as rugged as a 4WD mechanism - problem being, the locking mechanism is a sleeve, versus two full gears meshing - all said tho, it would only be an issue if it was abused, or was used for extensive off-roading (or possibly if you swap an Ej22 in), so you're probably fine either way

Well that gives me some food for thought. I think I will just look for a DR out of a nonturbo just for the better gearing. I found a turbo with LSD but I know that the gears are different between the two. Were there ever any LSD with 3.90 gears?

The 3.90 LSD is rare, can be found under some XT-6's. But like I said, rare.

 

You can swap the chunk out of the 3.70 LSD into your 3.90 though...