Fuse to disable rear wheel drive!

Why on earth would you do that?

Charles

I second Charles' comment. Why would you spend 25000+ on a new AWD car, only to disable the greatest feature of the car? Why not buy a FWD Hundai for half the price?

The "FWD" Fuse just prevents the Duty Solenoid C from allowing the clutch plates to send power to the rear. It only works on automatic cars. It's there solely to allow you to drive the car under power with a spare or other tire that's not the same size as the rest, without burning up the clutch packs.

Other than that, there's never a good reason to put the fuse in.

Then could you explain why my Legacy, with a manual clutch has one?

Wrong again, they are there to allow a safe tow, with a tow truck. But other then towing, there really is no reason to ever place the fuse in place.

"> Wrong again, they are there to allow a safe tow, with a tow truck. But

Big time wrong! You should NEVER tow an AT with any wheels on the ground no matter what. It is there for flats, as the other poster explained. Look it up if you think we are wrong.

DEFINATELY check the manual. The fuse has NOTHING to do with towing. It is there PURELY for using the temp spare with a flat.

Hum, have to fall in on Patrick's side on this one: Manuals have mechanicals center diffs, as far as I know, so putting a fuse in would have no effect. The fuse holder may be there but it's not used. Try it and see if you get the "FWD" sign in the dash. As to using the fuse and towing, the manual for my automatic 2000 Legacy states that a) towing should always, ALWAYS be done with all 4 wheels off the ground for automatics and b) the FWD fuse is to be used when the spare tire is used.

The automatic's clutch pack has both thick fluid and electronically controlled clutch plates to manage the transfer of power to the back. Putting the fuse in disables the electronic part, which moves the clutch plates, but some power is still getting to the rear so towing with 2 wheels on the ground would still cause the clutch to heat up and possibly cause problems. When using the spare with the FWD fuse the difference in rotational speed between front and rear is probably not enough to cause problems over the short term.

Scoobymods has info on how this happens for the VDC cars (

), in the firstthumbnail.

Nicolas

P.s. The car behaves like crap when the fuse is in, anyway, no point in overusing it...

For towing!

I got interesting in this thread so just got off the horn with my service mgr. He said, "Yeah some people put the fuse IN when they have the space saver spare on, but it's not necessary."

I repeated "IN?"

He replied, "Yes, IN!; there's a spare just for that purpose. Read your manual."

Don Username munged by FixNews

Why on earth would people believe that an electrical fuse would do anything while the car is off, being towed?

Come on people, it doesn't even make sense!

The fuse is there so that while you're driving an automatic-transmission car, the clutchpacks aren't constantly trying to overcome the perceived slip that occurs when one wheel is smaller than the others.

make the tow company send out a flatbed.

should be towing on a flatbed) is if you have to get emissions

wheel dynamometer. If they have to spin only two wheels, you don't

Check your manual. The fuse does NOT allow you to use a 4 wheel dyno. As posted previously, there are two components to the transfer case on the

4EAT - fluid as well as clutchpacks. You'll overheat the fluid if you try to run on a 4WD dyno. Subies (and all AWD/4WD vehicles) are exempt from dyno emissions testing if your state doesn't provide 4WD dynos. Don't let the guy at the station tell you otherwise.

Even in NJ they use the tailpipe monitoring as they only have two wheel dynos. Who would let the inspection station monkeys run an AWD on a 2 wheel dyno?

I'd expect to get better gas milage with the car in FWD. The tachometer seems to read about the same either way though. Maybe I'm confused, but it seems like the car works harder going up the mountains in 2wd... so I'd think that it'd do better on the highway than it does in AWD. Anyone?

P.S. I have a 2000 stick leg. outback. The manual implies that the fuse does the same for my car but there's no indicator light. Also, I don't know what this magic "under the spare" fuse is... I've used my pare before and saw no fuse - I just used the spare 30 fuse that's in the engine fuse box.

Using the fuse on a manual should have no effect as the manual's AWD system is totally mechanical, there is no electrical connection on it.

As to how cars behave when they are in FWD: Like crap. They understeer like nuts and the rear axle causes a lot of friction which makes the car seems like the rear is very loaded. Would be OK for a while on dry roads but was scary when I tried it on snow roads. And I don't see how it would affect MPG as the friction from the axle and such is still there. On older 4WD systems you had to disconnect the wheels hubs to get better MPG.

And I've never heard of a spare fuse under the spare... :-/

Nicolas

Taping one on top of the spare might not be a bad idea as a reminder to pop it in when you change the tire.

-DanD