The Problem : 1992 Legacy AWD non turbo automatic
With driveshaft in car and FWD fuse in box, when taking right or lefts the rear wheels lock up and make the whole car shake, and the rears peel out a bit (The car is locked in 4 wheel drive mode so all 4 tires spin equally). Also with driveshaft out the binding goes away however the gas mileage is about 14 MPG.
The Reason :
The rear wheels have to travel a farther distance then the front and since the car is locked in 4WD mode the rear wheels need to turn more but since they can't they lock up and drag on the ground instead.
Mileage may be caused from either the fact that apparently subarus are designed that when you first accelerate all 4 wheels have power and then it gradually moves the power to 90 front/10 rear. Also since the car isn't functioning correctly maybe the computer is confused and is applying to much gas to the car or something.
The solution (for me at least)
1) Drain the tranny fluid (on my legacy it was 8.8 quarts) and check for burn smell or debris. Fill tranny back up. If the problem just started and you got to it right away this should fix your problem.
2) If you found debris in your tranny fluid and filling it back up didn't seem to help check your tranny filter and see if that's gunked up.
3) If tranny fluid and filter all seem fine it's time to start getting
dirty:eek:. Get under the car and unbolt the frontside of th driveshaft and let it dangle down. Also in order to do that you should unbolt the guard in the back since the driveshaft probably won't move down enough for u to get it out. I personally unbolted the rear guard without trying so maybe u can get it out just fine without removing it.
4) Unbolt the section of exhaust that runs from your cat to your exhaust manifold I guess, not sure what it's called. It's between the place when your exhaust forks down from 4 pipes to 1 and before your cat too. I'm sure you'll figure it out. Also you will more then likely break some bolts, don't worry about it that's not much you can do that I know of since they are exhaust bolts. You will probably have to visit an exhaust shop afterwards, I did and it costs me 40 bucks to have that fixed.
5) Now hopefully all your tranny fluid is not inside your tranny you are gonna unbolt the back houseing of the tranny, it's pretty simple. You now have to coax the housing off the tranny, I used a chisle next to a mounting pin and a hammer to lightly make a wedge. Just be careful not to groove the housing where the gasket goes or else it will leak. Once I got enough of a gap that when I moved the housing up and down it jiggled I just started jiggling it till it came off.
6) Now unbolt the transfer clutch solenoid and get some alligator clips. Plug one clip to ground and one to hot side of battery terminal. You should hear a loud click when u do. Also if you truly want to test it once the solenoid has power blow on the little hole with your mouth it should let air pass through, and when solenoid has no power no air should pass through. If that doesn't seem to be working great you found the problem , replace and all should be fine.
7) If that seems to be working fine there is a sensor on the back of the houseing that needs no unbolting or messy stuff. You can pull it out and check it for debris, and also ohm it out with a volt meter. Should be about 600 Ohms working.
8) Ok now for where my problem was LOL. If all those seem just fine and you bought the car from some car for 600 bucks time to check the transfer clutches themselves. Opps they are all welded together and there are alot of signed of burning all around the gears. Time to replace it.
9) Time to grab some alot of razor blades, and start scraping. get as much of the old gasket off both sides of the housing, and make sure you get the top of the houseing from the side that's still attached to the car.
You can buy a gasket set of be cheap like me and use some instant gasket making, just make sure it resists oil. Also get some acetone or laceur thinner and wipe down both sides of housing really well. Apply gasket and carefully attach housing back together. Slap everything back together and MAKE SURE YOU PUT TRANNY FLUID BACK IN ( I did that once on my first car ) !!!!
10) Since you are down there why don't you change the front diff fluid and the rear as well.
Hope this helps someone else with my problem. Please reply if it does. Or if I missed anything.
Here are the pics I took plus an eletric diagrams for a 92 subaru legacy tranny
The housing you'll need to remove
housing.jpg 15.38K 235 downloads
Under the car shot with stuff removed
carriage.jpg 14.22K 241 downloads
Big difference between the bad gear and good gear. On bad gear all clutches were welded together.
gears-compare.jpg 14.61K 293 downloads