Hubs & Axle Vacuum Disconnect Basics

131 1103 Hubs And Axle Vacuum Disconnects Basics Jeep Cj Side Shot

While standing around kicking the concrete and shooting the breeze one day at T&J Performance Center in Orange, California, we got to talking about easy fixes. Some folks are wasting their hard-earned money because they're intimidated or too lazy to fix minor mechanical issues. It should be a rule of owning a Jeep that some of its repairs and upgrades be completed by the titleholder. Not knowing how to fix easily repairable mechanical problems out on the trail can lead to major problems. So get familiar with your rig and fix those headaches before they turn into disasters.

131 1103 Hubs And Axle Vacuum Disconnects Basics Manual Hub For Dana 44

Some manual hubs are extremely uncomplicated, with few parts, so their installation is easy. Some early Jeep front axles came with Warn locking hubs from the factory, but none with premium hubs. Warn premium hubs are much stronger and simple in design. The hubs for the Dana 44 axle on the Jeep Wagoneer consist of a clutch, a retainer clip and snap ring, and six Allen-head bolts.

Some manual hubs are extremely uncomplicated, with few parts, so their installation is eas

A good example of an easy repair/ upgrade is the replacement of the manual locking hubs and fixing the problematic vacuum-actuated axle locking system on the Dana 30 front axle. So what do manual locking hubs do? Locked hubs give the Jeep its four-wheel-drive traction by locking the front wheels to the axleshafts so they'll turn from the power of the transfer case when it's shifted into 4-Hi or 4-Lo. When the hubs are unlocked the wheel spins independently of the axleshafts and differential. Leaving a broken hub on the axle shouldn't hinder progress, and the rig may be able to make it back to the trailhead. However, a broken hub limits the Jeep's traction. If the rig is stuck in a tough situation, replacing or repairing the hub will likely allow the Jeep to drive out of it.

The Dana 25, 27, 30, and 44 Jeep axles have manual locking hubs and/or nonserviceable unit bearing hubs, and some use a vacuum-actuated axle lock. Most manual locking hubs are comparable in design and can be repaired, replaced, or retrofitted in a similar manner. Aftermarket hubs and their internal parts vary slightly but can all be installed and repaired using basic tools.

131 1103 Hubs And Axle Vacuum Disconnects Basics Drive Gear

Once the internals for the factory hubs are removed, the drive gear can be slid in place over the axleshaft. The drive gear is held in place with a flat inner snap ring that seats in a groove at the end of the shaft, and a large round outer snap ring that seats in a groove inside the hub housing.

Once the internals for the factory hubs are removed, the drive gear can be slid in place o

The Dana 30 under the Wrangler YJ, early Cherokee XJ, and Comanche MJ doesn't have manual locking hubs, but instead uses a vacuum-actuated central axle disconnect (CAD) system located on the passenger side of the housing. The system consists of a two-piece splined shaft and a coupler that slides back and forth by a vacuum-operated shift fork. The action of the fork either connects or disconnects the shafts. The dubious system uses a vacuum motor that can seize and rubber lines that rot.

The whole system can be replaced by a manual hub conversion kit, but such kits are a bit pricy. Just a few hundred bucks more (not counting installation) can get a larger and complete axle, such as a JK Rubicon axle complete with locker.

An economical fix is the 4x4 Posi-Lok system, or you can get locking hubs and a passenger-side axle assembly from a nondisconnect Dana 30 and slide in a new inner axle seal that fits inside the differential. Both the manual locking hubs and the 4x4 Posi-Lok are easy fixes that can be completed under an hour each.

The locking dial of the hub is bolted into place with six Allen-head bolts. Most Jeep Wagoneer 44s didn't come with manual locking hubs. Adding them will let the wheels spin freely in the unlocked position and stops unnecessary wear and tear on the axle and other drivetrain components.
The locking dial of the hub is bolted into place with six Allen-head bolts. Most Jeep Wago
To add the manual locking hubs to the Dana 44, we used flathead and Phillips-head screwdrivers, a pick, an Allen wrench, snap ring pliers, and a socket and ratcheting wrench. These are tools that should be carried on the trail. Spare parts for the premium hubs are readily available.
To add the manual locking hubs to the Dana 44, we used flathead and Phillips-head screwdri
The cable-actuated 4x4 Posi-Lok system is simple and straightforward to install. The toughest part of the installation is drilling a hole through the firewall to run the cable. The kit comes with everything needed to make the Dana 30 much more reliable.
The cable-actuated 4x4 Posi-Lok system is simple and straightforward to install. The tough

After the factory central axle disconnect is removed, its vacuum source on the engine should be plugged with the provided vacuum cap. Before the factory fork is installed in the new housing, it should be inspected and, if damaged, replaced. If the fork is replaced it should be swapped out with a cast iron fork.
After the factory central axle disconnect is removed, its vacuum source on the engine shou
With the actuating fork carefully placed in the axleshaft coupler, the housing can be bolted in place. The cable is then run up through the engine compartment and to the firewall. Care should be taken so the cable is not resting on or too near the exhaust system.
With the actuating fork carefully placed in the axleshaft coupler, the housing can be bolt
The cable-actuating knob comes with a bracket to mount it up and under the dash. To engage the lock, shift the transfer case into 4WD, press the button, and pull the cable into the fully engaged position. To disengage the lock, place the transfer case in 2WD, press the button, push the cable into the fully disengaged position, and release the button.
The cable-actuating knob comes with a bracket to mount it up and under the dash. To engage

SOURCES
T&J Performance Center Orance CA 714-633-0991 www.tandjperformance.com	4x4 Posi-Lok 104 S. Michigan Ave Coldwater MI 49036 517-279-7177 www.4x4posi-lok.com
Warn Industries 12900 S.E. Capps Road Clackamas OR 97015 800-910-1122 www.warn.com