Why the 2024 Jeep Wrangler's Dana 44 Full
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One of the most significant changes made to the 2024 Jeep Wrangler is also one of the most difficult to spot: The new Wrangler's rear axle is now a full-float Dana 44 HD. Why does this matter?
First, how are semi-float and full-float axles different? In a semi-floating axle, there is an axle shaft on each side that is splined on the inner end where it mates to the differential. Each end also has a wheel flange where the wheel studs mount at the other end. This assembly typically mates to the end of the axle housing using some type of bolted flange arrangement. The axle shaft rides on a large roller or ball bearing at the end of the axle housing. Semi-float axles are generally lighter and easier to manufacture, and they're found on lighter-duty applications.
For a full-floating axle setup, the axle shaft only serves to transmit the rotational torque from the differential out to the wheel. It does not carry the weight of the vehicle as a semi-floater does. On a full-floater, a spindle is attached to the outer end of the axle housing. The wheel hub is mounted on this spindle and rides on tapered roller bearings; this assembly carries the vehicle weight. As such, a full-floating axle system is considerably stronger than an equivalently sized semi-floating system.
For those of you who carry heavy loads, this means your axle-load capacity is much greater with a full-float axle. Load ratings for similar vehicles with the two different axle types are usually significantly different. If you do hardcore wheeling on big tires, a full-floater means your axle shafts can also handle much more loading than a similar semi-floater because it now must only handle torque loading.
Further advantages of a full-float axle include avoiding the scenario in this image: where a semi-float axle with a C-clip shears and exits the axle tube while on the trail. Full-float axles allow you to completely remove a broken axle shaft while keeping a functional rolling tire on that corner of the vehicle. This can be done since the wheel actually bolts to the wheel hub that rides on the spindle attached to the axle housing. If the axle is fitted with manual-locking hubs, it may be possible to unlock the rear hubs for towing a disabled vehicle on the trail or for flat towing over the road.
In short, no, you don't need one. However, the list of benefits could save enthusiasts from making a few upgrades to their Jeeps. Namely, off-roaders who desire larger wheels and tires will appreciate the additional strength afforded by the full-float Dana 44 HD. Anyone planning to tow a trailer behind the Wrangler will notice the increase in capacity at the hitch, and in the unfortunate scenario of a trail mishap, the rear axle shafts will remain inside the axle tube until the driver chooses to remove them.
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