legacycentral bbs

ok...so my girl has a 95 legacy LS AWD, its been shuddering latley...well a little inspection reveals the tires, although the same make and size, have quite abit of uneven tread wear, which leads me to believe that the rear tires are older then the front...i.e. someone replaced the front 2....
to reduce on drive train wear for the immediate future, or untill we can scrape up enough $$ to buy 4 matching new tires, can i just pull the switch and make her car a 2wd for the time being? is there any damage that this can cause, or will it prevent damage from happening?
Thanks,
Sam

yeah you can just insert the fuse in the FWD holder. you won't have any permanant damage from doing that.

ok, great thanks josh..i didnt think so either, but just wanted to ask the guru's

what amp fuse do you use to disengage the AWD?

You should note that Subaru says never to drive the car with the FWD fuse in place. They don't say why, though.

A potential problem is that installing the fuse turns Duty Solenoid C on 100% of the time to inhibit rearward torque transfer.

Ordinarily, the solenoid's highest duty cycle is around 90%. So, it continuously turns on and off many times a second and always gets a little rest.

It is theoretically possible that running it at 100% duty cycle could wear it out prematurely due to heat or lack of motion in the valve itself.

That said, almost any fuse would do... I'd say a 15 amp one would be fine. It pretty much just needs to carry enough current to light up the FWD warning lamp in the dash and to trigger whatever logic circuitry in the TCU interfaces with it.

It would be kind of ghetto, but maybe you could put both of the older tires on the left side of the car and both newer tires on the right side (or vice versa)? You'd have to be careful driving it, though, since the dynamics would be a little weird, probably making it a little twitchy on turns.

but maybe you could put both of the older tires on the left side of the car and both newer tires on the right side

I totally agree, do this no matter what. That would prevent any further damage to the center differential/clutch.

Can I piggyback on this post...please? I have three questions. First, what does duty solenoid C do, what is it's job? Second, where is it located? Third, is it costly to fix? I ask because my TCU threw a code for this solenoid twice (I reset it once and then it happened again) along with this strange bucking sensation. Am I looking at another trannie?

The solenoid controls pressure to the center differential clutch.

Do you know how a motorcycle clutch works? Its exactly like that. When the solenoid is off the clutch is locked, when the solenoid is 100% on the clutch is totally open.

It lives inside the extension housing on the transmission, on the drivers side near the top if I remember right.

As far as repairing it Id like to know as well.

vrg3 wrote:You should note that Subaru says never to drive the car with the FWD fuse in place. They don't say why, though.

A potential problem is that installing the fuse turns Duty Solenoid C on 100% of the time to inhibit rearward torque transfer.

Ordinarily, the solenoid's highest duty cycle is around 90%. So, it continuously turns on and off many times a second and always gets a little rest.

It is theoretically possible that running it at 100% duty cycle could wear it out prematurely due to heat or lack of motion in the valve itself.

That said, almost any fuse would do... I'd say a 15 amp one would be fine. It pretty much just needs to carry enough current to light up the FWD warning lamp in the dash and to trigger whatever logic circuitry in the TCU interfaces with it.

It would be kind of ghetto, but maybe you could put both of the older tires on the left side of the car and both newer tires on the right side (or vice versa)? You'd have to be careful driving it, though, since the dynamics would be a little weird, probably making it a little twitchy on turns.

This doesn't really make sense?

they say to put the fuse in to disable the AWD.....I would think putting that fuse in would run a continuous voltage to the duty c valve.....and I sure don't understand....don't drive the car with the fuse in place.....that's what it's there for.....

Yes, 100% is a continuous duty cycle. Putting the fuse in doesn't directly power the solenoid, though; it just turns on the idiot light and sends a signal to the TCU.

It's weird, but, yes, Subaru's literature says FWD mode is only for Subaru diagnostic technicians to use. I think they used to say you could tow a 4EAT 4WD Subaru with rear wheels on the ground in FWD mode but they retracted that statement.

My dealer told me to drive around in fwd mode for a week to check for a vibration I was experiencing on my 2000 4EAT legacy.

It did not help

I did eventually find the source of the vibration, and no apparent damage was done to the car.

The EJ25 can spin wheels quite easily in 2wd mode