AWD->FWD - Debate with friend, need answers.

[hfxdesign]

Alright, me and my friend are getting in a heated debate about whether or not running my car on just the front wheels is gonna trash the transmission. The back story is this: The duty C solenoid in my car fizzled out, and I don't have the time to replace it, instead I removed the rear section of the driveshaft (4EAT transmission), leaving the rear differential / axle shafts in place.

I'm not really seeing where there could be much of an issue, aside from extra stress on the front CV shafts. Anyone have some input on this to clear it up?

[Bhatman]

There is a fusible link labeled "FWD" which when you put the fuse in it will disable the AWD (only for 4AT transmissions). You can leave the rear running, but just moving excess weight of the diff and half-shafts.

I dont know how long you can run in FWD mode...but I do not think its for long periods of time.

[Felipe]

My car has that fwd fuse option, but i thought that was for towing purpose only?

[hfxdesign]

I'm not using the fuse, I have the rear section of the driveshaft physically removed. He thinks it's going to destroy the transmission since there's no power to the rear tires.

[Huffer]

I'd like to see a picture of what you removed. If you disconnected the driveshaft from the middle u-joint, the remaining part will be unbalanced and wobble... and eventually will destroy your transmission completely.

You'd have been better off putting the FWD fuse in, until you can afford to swap the transmission out.

[Felipe]

I dont know how long you can run in FWD mode...but I do not think its for long periods of time.

How long is too long with the fuse? Just curious.

[Bhatman]

I dont know how long you can run in FWD mode...but I do not think its for long periods of time.

How long is too long with the fuse? Just curious.

When you plug in the FWD fuse, that kills the duty cycle on the Duty C Solenoid to 0. Technically the solenoid with that fuse wont cause any damage, but before the solenoid could go out, the transmission as Huffer said would wobble due to being out of balance.

[Felipe]

I wonder if you can do the same and make it RWD? lol

[Muse]

You can't.

And I've been running FWD unless it's snowing since I crashed in October with no discernable ill effects.

[Felipe]

If running on just FWD does it get 100% to both front wheels 50/50?

[Muse]

Well, not really. If you have the fuse in, you'll get 100% to one or the other front wheels, unless you have a limited slip front differential..

[Grimmrican]

Or just weld it so it posse lol but that'll be dumb. But yea my dads BG ran with the fuse on his car for about 3 months until I did a transmission drain and fill. Ran perfect after that. AWD awesomeness was resurrected to his BG

[Felipe]

Is there such thing as a lsd for awd trans for front or back?

And sorry for the....

[Grimmrican]

Aww the pic is broken on my phone

I think there's a VCD for the car and a LSD and u can make the rear posse at like 80% torque on the rears 20% in the front

[Huffer]

There's plenty of LSD options for the rear diff - just depends on your gearing and what you want to do.
I don't recommend it if you're not proficient at skid-recovery though.

[Felipe]

80% to the rears.... Interestiningnig

Proficient Skid recovery... Does it count if my last car was 240SX with a vlsd :0)

[Grimmrican]

Yea iirc u can go up to 90% rear but not full 100%

[Felipe]

RWD legacy waggon



And says.... " removed front axle, kept the end to hold the wheel bearing together. welded center diff? to send all power to rear wheels only, replaced rear diff with factory lsd from legacy outback."

[Felipe]

[Grimmrican]

lol true

And not too long ago on my FBI news page I saw someone with a rwd wrx who did something similar

[Felipe]

Stock Lsd from an outback? So only outback came with lsd or was it an option of some sort.... I mean why get an lsd when the car is already awd?

[Grimmrican]

It's a little more complexed than being an AWD ill just let the next fellow under me explain how it really works.....

[Felipe]

Fine ill google\wiki it lol

[Muse]

Far as I can tell, with an open diff, a car is esentially one wheel drive, in the sense that there is only one actually getting the power at any given time. With AWD or an LSD you bring that up to two wheel drive (both drive wheels in a FWD/RWD or one front/one rear in an AWD.) With a rear LSD-equipped Outback, you have both rears and one front getting the power.

[Grimmrican]

Yea but I thought the AWD only turns off one wheel when turning to prevent binding....

[Huffer]

You guys are getting totally mixed up with AWD and LSDs.

Even a RWD car can have an LSD. It's not limited to AWD or FWD.

Read this for info on STOCK transmissions and setups. Once you get that, then you can move onto "what do I think I want to replace":
http://www.cars101.com/subaru_terms.html#awd

[Felipe]

It Talks about the split to front/rear, but it dont say if it sends power to both right/left or just one

And my 240SX was rwd with an open diff (power to one wheel) until i installed a VLSD.

[Neatfellen]

well then, I can certainly say that the thread def is off of the orignal question haha, but still fun to read the back and forth. As far as my manual said when I read through it, the Fuse option is only a temporary fix, does not say how long temporary is though, but would not recommend anything else to make your car FWD unless it was to use the switch per what was already brought up by Huffer. (btw mine is a 5 MT and I have the same fuse option to make it FWD so not to sure about it being only on the 4AT, maybe it changed on the 3rd gen that i have)

[Huffer]

It Talks about the split to front/rear, but it dont say if it sends power to both right/left or just one

And my 240SX was rwd with an open diff (power to one wheel) until i installed a VLSD.

Your 240SX is only confusing the issue - we're talking about Subaru's here.

The Subaru AWD system doesn't allow (at least in the pre-2005 models) for a left-right (yaw) control of sending torque. The only system that does is the VDC system which is typically only found in the Outback models.

well then, I can certainly say that the thread def is off of the orignal question haha, but still fun to read the back and forth. As far as my manual said when I read through it, the Fuse option is only a temporary fix, does not say how long temporary is though, but would not recommend anything else to make your car FWD unless it was to use the switch per what was already brought up by Huffer. (btw mine is a 5 MT and I have the same fuse option to make it FWD so not to sure about it being only on the 4AT, maybe it changed on the 3rd gen that i have)

A 5MT does NOT have a fuse to make it FWD. It's only on the ATs. I'd check under your hood again.

[Neatfellen]

It Talks about the split to front/rear, but it dont say if it sends power to both right/left or just one

And my 240SX was rwd with an open diff (power to one wheel) until i installed a VLSD.

Your 240SX is only confusing the issue - we're talking about Subaru's here.

The Subaru AWD system doesn't allow (at least in the pre-2005 models) for a left-right (yaw) control of sending torque. The only system that does is the VDC system which is typically only found in the Outback models.

well then, I can certainly say that the thread def is off of the orignal question haha, but still fun to read the back and forth. As far as my manual said when I read through it, the Fuse option is only a temporary fix, does not say how long temporary is though, but would not recommend anything else to make your car FWD unless it was to use the switch per what was already brought up by Huffer. (btw mine is a 5 MT and I have the same fuse option to make it FWD so not to sure about it being only on the 4AT, maybe it changed on the 3rd gen that i have)

A 5MT does NOT have a fuse to make it FWD. It's only on the ATs. I'd check under your hood again.

hmm, I didn't look overly close so its possible that its just a blank slot but still labeled as that but with no connectors in it.