spoonist

this might be a pretty stupid question, but you never ask you never learn.

has anyone ever thought/heard of the ability to switch from 2WD to 4WD to FWD?

if you can disconnect the front drivetrain, shouldn't it be possible to do the same for the rear (ex: transfer case in 4H but disconnect rear driveshaft)?

it seems like it would be possible to add manual hubs to the rear wheels and then switch to 'free' to activate FWD.

...if it's possible...would there really be any advantage? better fuel economy perhaps? better handling?

yes, i'm new to the forums, and yes, i'm not a mechanical genius, so flame away.

Ilovemountains

Anything is possible, Im not sure about the hubs on the rear beacuse the rear axle is solid to the diff. I have heard of people bottoming out their rear drive shaft and bending or breaking it and removing it all together and limping home in esentailly front wheel drive. I dont think the front drive system of a 4x4 is designed to pull all of the weight of the vehical all of the time, though the old VW Caddy mini pickups were FWD so who knows!

annoyingrob

If you unbolt the rear driveshaft, and place the vehicle you will put it in fwd.

You're not going to be gaining any sort of fuel economy though. The motor's still turning just as much mass through the front axles and differential as it would in RWD.

mt_goat

To put manual hubs on the rear you'd have to switch to a free floating axle. And you're looking at some big $$$ to do that, but I hear the free floating axles are great.

More info on FF axle conversion: http://frontrangeoffroadfab.com/nfos...a01a34bdc6da2c

spoonist

that makes sense, but would there be any advantage? basically the front range off road site says it's easier on the brakes, tires and bearings, but i've never heard of anyone having the kind of major issues they quote. The 4x4wire write-up says that braking is better, but all that guy wanted was disc brakes...$669 is too much to even bother if that's the only advantage...

4Crawler

iTrader: (3)

I've run many hundreds of miles in FWD on my truck with the rear driveshaft removed. Either due to breaking in new front gears or when the rear shaft was damaged on the trail. Handling is so much better in FWD, very stable on the highway and in turns. The last time I did so, I had 33x15.50 Swampers on my truck and they were pretty bad to drive on the highway, plus my truck had a bad case of death wobble in the steering. But in FWD, it drove perfectly smooth and stable with no wobble in the steering.

There is a little different feel though and that depends a lot on what you have in the front axle as far as a traction aide. With an automatic locker up front, handing is quirky, with a limited slip much less so, with a manual locker or open diff up front, you just need to expect the pull of the front wheels when accelerating in a turn, little different than driving a FWD car.

And yes, you can do the rear full floater axle conversion or you can get a rear driveshaft disconnect and shift into FWD without unlocking the rear hubs.

Matt16

Handling is better? Strange, I thought the handling would be all weird in FWD.

4Crawler

iTrader: (3)

Like I said, it depends on what you have for a front axle. I found the driving (with an open front diff) to be more stable, none of the wandering like you get in RWD. Since the front wheels are pulling you in the direction they are pointing, they tend to stay pulling in that direction. In RWD, I find I am constantly turning the steering wheel a little right then left and back as you drive a straight line, while in FWD it pretty much holds the line and you only steer when you want to change direction. But it is a different feel, when you accelerate in a turn, the steering wheel wants to pull back to a straight line, so you need to hold on a little tighter. My DD is a FWD VW pickup with a limited slip diff, so I am used to that.

spoonist

so basically other than slightly better handling there's really no need to run FWD unless necessary. seems like a waste of time and/or money when i have no problem with the way the truck handles in the first place.

thanks, guys!

4Crawler

iTrader: (3)

Yes, really no big advantage to it and a substantial cost to implement (outside of dropping the rear drive shaft which is free).

91Toyota

Also notice, it looks like 4Crawler has an 85, which means he has a SOLID AXLE in the front, You on the other hand, likely have ifs. There will be a difference.

abecedarian

Basic directional stability is better in front wheel drive, regardless of IFS vs SA, due to the front wheels pulling you vs the rear wheels pushing you.
The rear wheels only push one direction- along the centerline of the chassis, but with FWD, the thrust angle varies with the steering direction.

abecedarian

as for 2wd, 4wd, fwd, rwd....
contact gear vendors (http://www.gearvendors.com). they may be able to make a system to do what you want

Ed H.

rear driveline disconnect courtesy of front range offroad

abecedarian

well here ya go:

91diesel

I drove my 91 around in fwd for a couple of days waiting on my rear drive shaft to get shortened and my experience in an ifs rig doesn't mirror 4Crawler's experience. I found the front end pulled pretty bad on acceleration, much like the fwd turbo'd Chargers Dodge made in the late 80's. It generally just felt kind of squirrelly. Keep in mind I only did it for a couple of days (not the milage 4Crawler racked up) and in a chassis with alot of miles on it, however the front end is tight and with the rwd it doesn't do this.