jeryst Posted February 9, 2012 Share Posted February 9, 2012 I have always owned Subies with manual trannys and push button 4WD. Once you push the button, they act like a tank, never spin a wheel, and are extremely stable. In Jun I bought my first auto trans with full time 4WD (90 Loyale Turbo wagon). I havent had the opportunity to test it until today, and I can honestly say that after taking it down a couple of snowy roads, I HATE IT! The car is all over the road, the wheels just keep alternating as they search for traction. It doesnt feel stable like my old push buttons at all, and I am very disappointed. I would take my old push buttons through two feet of snow without the slightest concern, but I would be afraid to take this thing through 6 inches. It's not a tank, like I am used to. So my question is, is there a way to convert the full time 4WD to the same type of push button 4WD that was in my other cars? Link to comment Share on other sites More sharing options...
nipper Posted February 9, 2012 Share Posted February 9, 2012 A locked one would do the same as they are both open axles front and rear. The 4eat uses a computer to balance the torque split from 10/90 to 50/50 and everything inbetween. Your tires are the weak point in this equation. Unless oyu had a 4wd vehicle to match with similar tires track and weight, I wouldnt blame the auto as it really does wheel very well. You can set it up easily enough but first look at what kind of tires you have. I ahev ownd a DR subaru and it would go all over too due to road conditions. AWD keeps you going as long as you have traction, not necassarily straight. Thats where tires come in. Link to comment Share on other sites More sharing options...
WoodsWagon Posted February 9, 2012 Share Posted February 9, 2012 (edited) The earlier TCU's for 4eat's had a longer delay for the rear engagement and the hydraulic passages for the rear transfer clutch are smaller so that adds to the slow response. Replacing the TCU and the rear transfer assembly with a newer version will make the AWD work much better. You can put in a power cut switch to force it into 4x4 instead of AWD. That will make it handle the same as your pushbutton 4x4 5spd's. Search for 4eat lock switch or something like that and it should come up. Threads like this: http://www.ultimatesubaru.org/forum/showthread.php?t=105077 If you build a dummy load out of resistors that the signal from the ECU gets shunted to when you cut it to the Duty C solenoid, then it won't throw codes. You should be able to turn up all the info needed with some searching. Edited February 9, 2012 by WoodsWagon Link to comment Share on other sites More sharing options...
987687 Posted February 9, 2012 Share Posted February 9, 2012 This link is for an impreza, so the wire colours will probably be different. But it's essentially the same transmission. http://www.rs25.com/forums/f8/t99075-4eat-diff-lock-switch-handbrake-mod-torquemada-lite.html Link to comment Share on other sites More sharing options...
jeryst Posted February 10, 2012 Author Share Posted February 10, 2012 A locked one would do the same as they are both open axles front and rear. The 4eat uses a computer to balance the torque split from 10/90 to 50/50 and everything inbetween. Your tires are the weak point in this equation. Unless oyu had a 4wd vehicle to match with similar tires track and weight, I wouldnt blame the auto as it really does wheel very well. You can set it up easily enough but first look at what kind of tires you have. I ahev ownd a DR subaru and it would go all over too due to road conditions. AWD keeps you going as long as you have traction, not necassarily straight. Thats where tires come in. It currently has Goodyear winter tires all the way around. I used to run all season radials on my push button cars. Link to comment Share on other sites More sharing options...
jeryst Posted February 10, 2012 Author Share Posted February 10, 2012 This link is for an impreza, so the wire colours will probably be different. But it's essentially the same transmission.http://www.rs25.com/forums/f8/t99075-4eat-diff-lock-switch-handbrake-mod-torquemada-lite.html Okay, I'm not much of a mechanic, or electrician, so I have a couple of simple (and probably glaringly stupid) questions, so bear with me. 1. What would happen if I just disconnected the solenoid on my car? 2. Is there a fuse for the 4WD on my car, and what would happen if I just pulled that? This is a 1990 Loyale Turbo Wagon with AT and full time 4WD. Link to comment Share on other sites More sharing options...
987687 Posted February 10, 2012 Share Posted February 10, 2012 Okay, I'm not much of a mechanic, or electrician, so I have a couple of simple (and probably glaringly stupid) questions, so bear with me. 1. What would happen if I just disconnected the solenoid on my car? 2. Is there a fuse for the 4WD on my car, and what would happen if I just pulled that? This is a 1990 Loyale Turbo Wagon with AT and full time 4WD. The way the solenoid works is this. If you give it full power it will be FWD. This is what the FWD fuse does. If you give it no power it locks in 4wd, essentially. So yes, you could just have a switch to remove power from the solenoid. The issue with doing that though, is it upsets the transmission computer. Suddenly it can't find the solenoid and puts the computer into limp mode. That's why you have to add a dummy load to make the computer "think" it's commanding the solenoid, when in fact it's just giving power to a resistor pack. It's weird it's not working well in the snow though, have you verified that the transmission is actually sending power to the back wheels at all? You can either jack one side of the car up (right wheels on the ground, left wheels off the ground). Then both a front and back wheel should turn. You can also unplug the harness connectors going to the transmission. This will put it in limp mode, meaning locked in 3rd gear and locked center clutches. Do some tight turns on pavement, if you feel it binding up, you know the clutches are locking. Over time and age the clutches can wear out and not grab, which might be what's causing your awd to suck. It might be broken. Link to comment Share on other sites More sharing options...
zukiru Posted February 10, 2012 Share Posted February 10, 2012 they are not glaringly stupid questions, but they are answered in the link. if you just disconnect the solenoid without adding a load.... you can put the transmission computer in limp mode. which is not good. is it was a simple as pulling a fuse there wouldn't be a how to thread. Link to comment Share on other sites More sharing options...
987687 Posted February 10, 2012 Share Posted February 10, 2012 You can go ever further and make a PWM motor controller to basically give you a DCCD... I'm looking into exactly how I'd do that, but it's definitely possible. Link to comment Share on other sites More sharing options...
jeryst Posted February 10, 2012 Author Share Posted February 10, 2012 It's weird it's not working well in the snow though, have you verified that the transmission is actually sending power to the back wheels at all? I can definitely feel it changing, but it acts just like the description in the "how to " thread mentioned above. Going around a corner, it acts like a FWD and starts spinning. I have to let off of the gas to be able to steer around the corner. When I give it gas again, I can feel it shifting power to different wheels, like it is searching. No where near as nice as my push button cars. I couldnt get them to spin a wheel for anything. They just dug in and went. Link to comment Share on other sites More sharing options...
WoodsWagon Posted February 10, 2012 Share Posted February 10, 2012 Find the wire that runs from the TCU to the Duty C solenoid on the TCU connector in the cabin using the right wiring diagram for your year. Cut the wire and splice in a single throw double position switch. When the switch is in one position it will connect the center pin (which you wire to the TCU side of the cut wire) to the wire going to the Duty C solenoid. That's the normal AWD position. When you move the switch to the other position, it disconnects the signal coming from the TCU and connects it to the other pin on the switch. You can leave that pin unhooked, but it will throw a code for a failed solenoid and the a/t temp light will flash. If you build a resistor pack to mimic the solenoid and connect that to the unused pin on the switch on one side and ground on the other, then the computer will think the solenoid is still there and working. By disconnecting power to the Duty C solenoid you allow full hydraulic pressure to apply the rear clutch pack. That will lock it in 4wd. Link to comment Share on other sites More sharing options...
nipper Posted February 10, 2012 Share Posted February 10, 2012 I think the problem may not be the AWD per se, but a tired clutch pack. Link to comment Share on other sites More sharing options...
idosubaru Posted February 10, 2012 Share Posted February 10, 2012 (edited) cut power to the Duty C and put a wire/switch in place to turn it on and off to give you full "locked" performance. it's well worth the effort. it's one wire, not a big deal. tires are huge - are they brand new winter tires? they don't retain like new traction very long, they age, unless they're Nokians. memory is a powerful thing, you will likely never reach the memory of your push button experience. hundreds of subaru owners (me and many friends included) have high centered plenty of subarus in far less than 2 feet of snow, i would not consider that description anything close to normal. Edited February 10, 2012 by grossgary Link to comment Share on other sites More sharing options...
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