How does this front hub 4x4 thing work?

[Timmyjoe]

Was into "4-wheeling" back in the 1970's and early 1980's. We had Jeeps, Toyota 4x4's and Ford F-150 4x4's and they were all pretty similar. Full frame, manual transmissions, manual transfer cases, solid front & rear axles, manually locking front hubs.

I understand most of how the JL works, but I'm confused by the front end and the lack of "locking hubs". Are the current Jeeps set up like my 2002 Honda CRV where they are pretty much "full time AWD" where the front hubs are always connected to the transfer case? And if so, doesn't that hurt gas mileage? We always manually unlocked the front hubs when we weren't offroad to save wear and tear on the front drivetrain and to get better gas mileage. How are the front hubs unlocked on the JL, or are they "full time" connected to the front axle and drive shaft?

Thanks.

Best,
-Tim

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[chevymitchell]

Was into "4-wheeling" back in the 1970's and early 1980's. We had Jeeps, Toyota 4x4's and Ford F-150 4x4's and they were all pretty similar. Full frame, manual transmissions, manual transfer cases, solid front & rear axles, manually locking front hubs.

I understand most of how the JL works, but I'm confused by the front end and the lack of "locking hubs". Are the current Jeeps set up like my 2002 Honda CRV where they are pretty much "full time AWD" where the front hubs are always connected to the transfer case? And if so, doesn't that hurt gas mileage? We always manually unlocked the front hubs when we weren't offroad to save wear and tear on the front drivetrain and to get better gas mileage. How are the front hubs unlocked on the JL, or are they "full time" connected to the front axle and drive shaft?

Thanks.

Best,
-Tim

Tim,

You'll need to read about the Front Axle Disconnect (FAD) system in the JL.

The passenger side front axle shaft is two pieces. These two pieces are connected by a collar when you move the transfer case lever into 4H or 4L. This will make the front differential operate as an open carrier. With the FAD collar not engaged, the front diff does not turn therefore the front driveshaft does not turn.

If you look on your front axle, passenger side, you'll see an electric motor/module mounted on the back side. This motor has a fork which slide the collar back and forth.

 

[Nutmeg]

The part time system uses an electronic coupler on the long axle along with the transfer case. As such on one side the axle and spiders are always spinning and on the other side the axle outside the coupler is turning when not engaged. When the transfer case is engaged the axle coupler locks the axle and power comes thru the front drive shaft to the diff and out to the axles. IMHO greatly inferior to the older design using locking hubs..

 

[aldo98229]

Look for the lever right next to the 8-track...

 

[Timmyjoe]

Thanks for everyone's replies. I'm a big fan of simplicity. I wonder if an aftermarket company makes a bolt on replacement for the front axel, one that has the simple locking hubs, like the old days, so as to bypass all that electronic stuff and Keep It Simple Stupid!

Best,
-Tim

 

[Gurk]

Was into "4-wheeling" back in the 1970's and early 1980's. We had Jeeps, Toyota 4x4's and Ford F-150 4x4's and they were all pretty similar. Full frame, manual transmissions, manual transfer cases, solid front & rear axles, manually locking front hubs.

I understand most of how the JL works, but I'm confused by the front end and the lack of "locking hubs". Are the current Jeeps set up like my 2002 Honda CRV where they are pretty much "full time AWD" where the front hubs are always connected to the transfer case? And if so, doesn't that hurt gas mileage? We always manually unlocked the front hubs when we weren't offroad to save wear and tear on the front drivetrain and to get better gas mileage. How are the front hubs unlocked on the JL, or are they "full time" connected to the front axle and drive shaft?

Thanks.

Best,
-Tim

Tim,
Yes the hardcore axle builders like Dynatrac and Currie use manual locking hubs but they are serious money. I would give a ring to a place like G2 Axle & Gear and see what they suggest, or can build for you, as they offer their own axle assemblies and are more budget friendly.

Good Luck

 

[Sean L]

Thanks for everyone's replies. I'm a big fan of simplicity. I wonder if an aftermarket company makes a bolt on replacement for the front axel, one that has the simple locking hubs, like the old days, so as to bypass all that electronic stuff and Keep It Simple Stupid!

Best,
-Tim

It would probably be cheaper to just buy a CJ-5 lol.

 

[Timmyjoe]

It would probably be cheaper to just buy a CJ-5 lol.

Yeah, but what fun would that be? HA!!!

I'll look into changing out the front axel once the Jeep is out of warranty. Would like to have all the conveniences of our JL, with the offroad simplicity of the old lock out hubs.

And aldo98229, no 8-tracks, just under dash cassette players as most of the vehicles came with just a simple AM radio. Nothing more fun than cassettes bouncing around the passenger floorboard as you twist and turn down rocky trails.

Best,
-Tim

 

[Sean L]

Yeah, but what fun would that be? HA!!!

I'll look into changing out the front axel once the Jeep is out of warranty. Would like to have all the conveniences of our JL, with the offroad simplicity of the old lock out hubs.

And aldo98229, no 8-tracks, just under dash cassette players as most of the vehicles came with just a simple AM radio. Nothing more fun than cassettes bouncing around the passenger floorboard as you twist and turn down rocky trails.

Best,
-Tim

I don't know... I still think a CJ-5 would be pretty fun.

 

[sourdough]

With manual hubs get you much better Timkin bearings on a spindle thats long enough to seperate the inner and outer for greater strength. I got rid of my Mopar unit bearings on my Ram 3500 4x4 with Yukon hubs. It doesn't have a weak FAD axle tube either like our JL's.

 

[JimLee]

Thanks for everyone's replies. I'm a big fan of simplicity. I wonder if an aftermarket company makes a bolt on replacement for the front axel, one that has the simple locking hubs, like the old days, so as to bypass all that electronic stuff and Keep It Simple Stupid!

Best,
-Tim

Dynatrac...

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