DIY 4EAT AWD mode locker

[Murphy]

alight! i finaly finished putting in the switch to lock my car in AWD, it takes control away from the TCU and lets you control it with the flip of a switch
it works by placing a switch in the line heading to your Duty C Solenoid, when its flipped on, the TCU has control of the rear end, when its flipped off, it cuts power to the soleniod, which locks the clutches together, which locks you in AWD 50/50 torque split, i have done a ton of playing aronud with mine after i finished it to test it out, and it works like a charm, no way to go wrong unless you get the wrong wire

heres a link to the ful instructions, skip to page 11, thats were deatialed instructions and pictures are
http://www.ultimatesubaru.org/forum/sho ... hp?t=48865
but i noticed that on his Impreza, he said his connector was under the air box, but im pretty sure most of you connectors will be directly over top of your torque converter, just in front of the firewall

it drives like a 4x4 truck, cant barely turn if your on pavement, but you wont be able to make it spin, i played with it in the backyard, i wolud floor it and sit and spin without moving, but i flip it off and it hooks like no other, cant wait for winter

[DLC]

Cool.

[555BCTurbo]

Very cool...so you now have a DCCD

[BXSS]

So when its off it runs like normal or FWD/RWD (Spinning tires without moving)?

[Murphy]

well, the "off" posistion is actually "on", since you lock it into AWD by cutting the power off
and when its in the "on" posistion, its normal driving, i thought about getting a 2 fuction switch and hooking the FWD fuse line into it
so it would be like AWD/normal(off)/FWD
just to save the hassle of putting a fuse in if i ever need to

normal is pretty much FWD though its a 90/10 split, if the car is jacked in the air and in Drive, you can stop the rear wheels with your foot
but if AWD kicks in, you definatly wont be stopping it

[dropdfocus]

That's very cool. I may just have to do that to my '92 for the winter months. Thanks for the info!

[Manarius]

Meh, I've found that the TCU does an adequate job of defining torque split. On my 91, there was never a time where I couldn't get it to 50/50 anyways. On my SVX, it takes a little bit to split enough for the rears to catch (like a car length), but it still catches nonetheless.

I figure, if it ain't broke, don't fix it

That is a cool mod though.

[speedoboy31]

had a 92 awd auto. tapped into the power wire @ ecm (inside car) hooked up a switch to make/break the connection. worked like a charm. used the switch for play mainly. burn outs in the snow and ice were a blast!!!!! did the mod with the intention of not making the 4wd slam in instead of already being engaged. just a side note, during winter driving,the computer controlled t-case is easier to manage @ speed. in full 4wd mode, the car wouldn't hold as solid of a line, the rear was pushing too much. of course that was during 70mph snow storm playing(my version of rally)

[Saskatoon Subaru]

alight! i finaly finished putting in the switch to lock my car in AWD, it takes control away from the TCU and lets you control it with the flip of a switch
it works by placing a switch in the line heading to your Duty C Solenoid, when its flipped on, the TCU has control of the rear end, when its flipped off, it cuts power to the soleniod, which locks the clutches together, which locks you in AWD 50/50 torque split, i have done a ton of playing aronud with mine after i finished it to test it out, and it works like a charm, no way to go wrong unless you get the wrong wire

heres a link to the ful instructions, skip to page 11, thats were deatialed instructions and pictures are
http://www.ultimatesubaru.org/forum/sho ... hp?t=48865
but i noticed that on his Impreza, he said his connector was under the air box, but im pretty sure most of you connectors will be directly over top of your torque converter, just in front of the firewall

it drives like a 4x4 truck, cant barely turn if your on pavement, but you wont be able to make it spin, i played with it in the backyard, i wolud floor it and sit and spin without moving, but i flip it off and it hooks like no other, cant wait for winter

can i get these pictures?

[mexicanzero]

heh i just resurected an old thread cuz i didnt realize this one was started.
http://bbs.legacycentral.org/viewtopic.php?t=32124
thats the thread my post is the really long one at the end lol

i put a 3 postion switch in so i have FWD not that i will ever really use it although i plan to do a test to see if i can get better fuel efficiency in the summer when theres good traction. the question i asked in the other thread is would the duty c solenoid having 12 v constantly (FWD) damage it in any way?

and also i was told that if you just interrupted the supply to the duty c you would get 4wd lock but it would set a code so you had to ground it not just interrupt it.
do any of you guys have an eng light on when in locked 4wd or flashing power light on startup?
thanks
-Alex

[ericem]

It makes sence for the power light to flash on startup in 4wd since it will show the circuit as open tripping the solenoid c code.

[slunk33]

I just did this mod in literally 10 minutes. So simple. The Power light does flash at startup. I haven't checked to see if I turned the switch on (back to normal) before shutting the car off and having it that way when I restart it would throw a code. I wouldn't think so, but then again, you would have to remember to turn it off. Maybe I can wire in a relay to have it on at start up then turn the switch off.

I put my switch right between the seats next to the emergency brake. I will locate my power lock switch in the same location. Easy access.

Will post pictures when the weather warms up. Highs are in the high 20's right now.

4WD works beautifully! I feel like I'm driving a rally car, so sweet! So Worth It! Highly recommend.

[dropdfocus]

Well, guess I'll be doing this mod to Trixie since everyone is having good success with it.

My only unanswered questions at this point are:
- you can do this "on the fly" correct?
- and if yes, is there a max speed you should be aware of when enabling the switch?

[wtdash]

- you can do this "on the fly" correct?
- and if yes, is there a max speed you should be aware of when enabling the switch?

Yes, flip it on the fly, but turn off when done/before restarting.

No known max speed, based on the fact this isn't supported by Subaru.

I did this on my '90 due to worn transfer clutches (now fixed) last winter, and it worked great. I had a delay in the AWD kicking in the rear wheels, but w/this mod, I had 4WD instantly.

It will throw a code for the Duty C solenoid and you'll get the 16 POWER flashes when restarted. And then it'll store it in the 'code history', but won't flash until it's used again.

DO NOT USE THIS ON DRY PAVEMENT! You'll ruin your rear transfer clutch/AWD system (kind like 'reverse' torque bind??)

And don't mount the switch where you'll bump it...you don't want to bump it and drive around w/it on...although it's pretty obvious when it's engaged.

[ericem]

I wanted to try undoing the pin from the connector, but the damn thing would not come out. Was fudging and pushing for a bit, (i did open the lock on the back of the connector if your wondering) tried getting a flat screw driver in there incase there is something its locking into, just ended up messing up the pin a bit. Are you guys just cutting the wire?

[wtdash]

Did mine @ the Trans harness under the pitch stop/between engine and firewall.