How much MPG could I save by removing the front drive shaft?

[SteveD2]

My cherokee is 4WD, although I don't use it much. Even in 2WD mode the front drive shaft is allways spinning. I'm thinking about removing it, both for the weight savings and the fact that the front axle won't have to make it spin anymore. Do you guys think it would be worth it for MPG savings? How much do you guys think I could get?

 

[Digital2k2]

ever considered getting manual hubs? that way you can lock it if you want to use 4wd and unlock it to keep everything from spinning, makes for less tear on everything and will give you a little better mpg, maybe 1mpg better?

guys who do serious off-roading also install these because they're more reliable and tend to work better. warn manual hubs is a good brand

 

[Whimsey]

Digital,
That Cherokee doesn't have front hubs. It uses a axle disconnect system. Also he may have the Jeep's "full time" 4wd set because I don't believe that the front drive shaft would be turning in 2wd if it had the "part time" 4wd set up. I'm sure one of our jeep owners on the site can go into greater detail or correct me if I'm wrong

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Whimsey

 

[Gary Allan]

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How much do you guys think I could get?

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ZERO MPG gain. You're added cosumption is from the wheels driving the axles spinning the differential gears and the drag is substantial. The driveshaft is the lightest part of the deal.

quote:

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That Cherokee doesn't have front hubs.

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Of course it has front hubs. Just not "lock out" or locking hubs J/K

. Yes, the Cherokee merely engages the front driveshaft at the t-case (some years had an axle disconnect on the passenger's side utilizing a vacuum motor)

quote:

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ever considered getting manual hubs?

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This is doable ...and produces real results. The WARN kit is expensive, however. I've done this conversion. The kit was a deal @ $695 ..I had to have two rotors machined to fit the hubs ..and since I wanted to still use my Canyon OEM alloy wheels ...I got them machined as well. Installation is straiht forward and simple.

All together I spent about $900 ...which would be a decent amount of fuel. Naturally I intend to keep the jeep forever ...so I can justify the expense ....expecially with 18k plus annual mileage.

This mod has yielded about 2.5 mpg

[ January 27, 2004, 10:22 AM: Message edited by: Gary Allan ]

 

[MarkC]

So Gary, How difficult and expensive to convert a 2WD to 4WD?
I'm going to keep my 96 until it won't move.
So far, I've never really needed 4WD. If I go to 'the woods', I dn't want to drive much anyway, just as far as I feel I can go, then park it and hike.
But I've sometimes thought it might be nice to have to 4WD option.
I'm getting 18-20 mpg combined mileage here, with about 22 or 23 on the highway, with the 5speed.

 

[Gary Allan]

Converting to 4wd is doable in just about every vehicle that offers both. Unless you're doing the work, however, it's darn expensive. Most hardware is available relatively cheap (t-case, front axle assembly, etc.) ..but the labor, although not necessarily overly skilled, is substantial.

I would recommend a limited slip differential for your needs. This should provide most of the access that you desire. If you really want "get out if I got stuck" capability with your current vehicle ....a winch is a far cheaper alternative to converting from 2wd to 4wd.

 

[MNgopher]

As has been pointed out, your gain would be minimal. If you could disconnect the axles and keep the diff from spinning and all of that with manual hubs, then you'd be in business. Not a cheap option on the Cherokee!

Anything is possible - coverting a 2wd to a 4wd is doable, but costs enough $$ you'd be better off selling what you've got and buying a 4wd.

The LS is a good option for adding some extra traction capabilties to a 2wd!