AWD into FWD only?

Is it safe to put the fuse on and make an AWD into a FWD only? What are the risks, if any? Or is it even recommendable? Thanks...

you should only use that in certain instances like towing. if you leave it in for long periods of time you will be eventually buying a new tranny and rear.

I had a mechanic tell me that you could drive it indefinitely as front wheel drive with no problems. It disengages the rear differnetial.

But here was my situation: I was having the rear binding problem when doing sharp turns. When i inserted the fuse to make it front wheel only, the binding stopped. The mechanic said I could drive it that way as long as I wanted with no problems. I liked having AWD too much, and decided to put up with the binding (since I do not make too many sharp turns). I later flushed the tranny fluid and it stopped doing the binding for a little over a year, then the tranny started making noises and eventually had to be replaced.

SVXpert may know better than me, since I am not knowledgeable into the internals of tranny's. His advice might be best. My situation did not last long enough to know for sure.

Rich

Rich, I'm trying not to be a jerk but is your mechanic a "subaru" mechanic or does he know anything about specifically AWD or subaru's in general? I think most of us on this board willl agree that a subaru is a very awkward car to work on and takes alot of knowedge . Simply put, there is no other make like it. It combines AWD with a boxer engine. you won't find that anywhere else but in newer porches. My advice to you is to find a compidend mechanic to work on these cars because most mechanics I know won't touch them. And those who try end up messing something up. What part of the states are you from?

Driving with the FWD fuse will NOT hurt an AWD transmission. Driving with it binding WILL.

Lots of people in Colorado (where gas mileage is poor due to altitude) put the fuse in for the summer and take it out for the winter. Driving in FWD mode substantially increases your gas mileage.

Emily

www.ccrengines.com

Ccrinc...

Is this also true of AWD Subes with manual transmission? Could I remove the rear part of the drive shaft and drive FWD without any problem? I might do this to test the origin of a small but annoying vibration (pulsation) and want to know if I can leave the car like that for a long time if need be.

Gilles

I am not trying to be a jerk either, but can you tell me where you get your information. I have read all the Subaru literature on and nowhere do they say anything about the effects of running in FWD mode.

I have spent quite a bit of time inside the automatic transmissions & I do not see how running in FWD will damage anything. Installing the fuse simply closes the Duty Solenoid "C" which dissengages the transfer clutch & power to the rear wheels.

Again, not trying to be a jerk but if you have some solid info that running in FWD does damage things, I would be eager to learn about it.

I would guess that the damage could be done if you left the FWD fuse in for years and years continuously and then tried to reactivate AWD. When mechanical systems are not used for long periods of time, they tend to deteriorate and have problems when they are reactivated. I can't think there would be any problem with deactivating the system for the summer months and then reactivating it for the winter.

Drew, I'd have to agree with you there.

The FWD fuse is only for AWD automatics, not manuals. And this is only available in the '90 and up Legacy, Outback, Forester models. Was NOT available on Loyales.

One of our customers saw an increase of 3-4mpg average.

Emily

www.ccrengines.com

A little embarassed to insist : I know I cannot use the fuse solution but can I remove the rear part of the drive shaft and drive FWD for a long period without damage? Someone knows something about that?

Gilles

You could take out the rear half of the drive shaft(if it is suitably supported by the carrier bearing) with out hurting the Standard tranny, but must leave the front section in to prevent all the gear oil from coming out the rear or the tranny.

I've been running the FWD fuse in our 91 AWD Legacy Wagon all summer with no ill effects,and it does get a little better milage(maybe 2-3 better), but with gas prices today, every little bit helps.

Have seen a few car that have wired a switch to the fuse so they could turn it off and on from in the car, planed on doing this myself before winter.

My 2 cents,

I spoke with the regional SOA service manager during a test drive to confim my driveline vibration TSB problem (I had also just had my entire tranny changed, starting with the torque binding problem - long story). THE SOA REGIONAL SERVICE MANAGER CONFIRMED THAT YOU CAN LEAVE THE FWD FUSE IN INDEFINITELY ON AUTO MODELS WITHOUT DAMAGING THE TRANNY! He also confirmed that you could engage/disengage the FWD feature (with switch in cockpit wired to fuse location) at will even while on the move. It was his opinion that you would experience NO mpg gain since you are still having to drive all the AWD components consisting of the propellar shaft, rear diff, etc, with their frictional contributions.

Hope this helps to clarify the debate.

Subibertie

97 OB 4EAT

SVXpert,

The mechanic is the lead mechanic at my local subaru dealer. He told me that he has driven his that way 6 months at a time, and then just uses the AWD in winter. I live in East Tennessee, by the way (the part with mountains and plateaus).

Rich

I apologize for any mis-information I gave out about this subject. After reading all the posts, I have come to the conclusion that my mechanic is on crack!

is this just for awd to fwd or can my 4wd legacy turbo be put into fwd? i looked for the place to put the fuse but i can't seem to find it... at least not what i expected if it is it. i found a wire that has an empty plug but it doesn't look like it's for a fuse, it is however attached to the couple cylinders(2wd) that are pictured in the manual but i don't know how i'm going to get a fuse in there the plug has little metal conectors that are arranged inside the plug as so: -I (one horizontal and the other is vertical). any ideas?

The fuse holder for the FWD is in the engine compartment between the right(passenger)side strut tower and the firewall.

yeah that's where this was, is it at the end of a wire kinda hanging off by itself??? sorry for the vagueness but i don't know how else to put it.

The wire you're refering to must be a connection for an accessory, the fuse holder should have a cap on it marked FWD, it takes a standard fuse (2 horiz. slots)

I believe its in the "under the hood" fuse box on my SVX and labeled FWD, you might look there as I didn't catch what Subaru you have.

As stated before if your car is a manual it does not have this option. It has to be an automatic to be able to turn off the AWD. So if yours is a manual you will not find a place to put a fuse.

cjt

no it's an auto. 4wd legacy turbo.... so is the fact that it's 4wd and not awd the problem? i will check the "fuse box" though, as i haven't done so yet. huckster- yeah, the wire looks like it plugs into something as the plastic housing of it has a snap that would probably hold the two connections together. any idea what in the world this could be?

Might be a conection for cruise control, or maybe the air suspension.

If you have a lever or button to activate your 4WD then NO you can't use the fuse trick, if you don't have a button to activate the AWD then you should be able to do it.

huckster- from what i can tell out of my haynes manual it does look to be for an air suspension system.

little update: i checked the fuse box(underhood) and nothing to do with the 4wd.

Subibertie - I would like to know more about your repairs involved with curing your torque-bind problem if you would'nt mind. I am going thru this same ritual of using the fuse to defeat the awd, and need to address the binding some day. I stopped using awd while the trans still works fine, and hope that all I gotta do is work on the trans extension housing - if you'd like, feel free to email me - dbcooper@mail.saabnet.com

thanx! Toecutter

Saabsubedude,

After 2 service visits to my local Subi dealer and several calls to SOA I had to self diagnose both my torque bind and driveline vibration problems (both with TSBs) and present them with my conclusions. There are several posts by myself and others since about October last year on the subject.

Once verified that I had the torque bind, the docunmented fix is to replace the extension housing and some of the internal components such as the duty solenoid C and transfer clutch. The problem is that a teflon seal between the aluminum extension housing and the powerdrain for the AWD causes the aluminum to wear, resulting in seepage of fluid which causes the duty solenoid C to seize up. The job (estimated by some) is about USD 800 and a previous post has all the part numbers. Apparantly this problem is common on many auto Subes between 50 and 55K.

In my case, while my Subi dealer was looking for the driveline vibration problem, they also decided that the tranny needed replacing due to some metals particles. hance they replaced te entire tranny, including the extension housing they had just replaced for the torque bind! In my case everything was still under warranty!

Hope things work out for you.

Subibertie

97 OB 4EAT