Jeep Cherokee Upgrades: Manual Hub Conversion, Axle Replacement

Sep. 01, 2016 By Jim Brightly, KF7SCT
All back together and running well. With hubs engaged the front tires are pulling the Cherokee up the slope and throwing dirt behind them.

When Mike Barnes bought new tires for his 1997 Jeep Cherokee from Summit Racing, he had no idea that the increased traction of the Yokohama Geolandar M/T tires over the Cherokee’s former tires might expose a weak link in his driveline. When he found out from fellow club members that, in many cases, the enhanced traction of mud-terrains almost eliminated the need for selectable lockers, he became worried and decided to upgrade his front axles.

When faced with the decision of choosing between a tire that offers good mileage or good off-road traction, if traction is the choice it usually will come at the expense of extended tread mileage. That’s not the case with the new Geolandar M/T. The tire is constructed with a directional tread pattern for outstanding off-road grip and easier clean out to remove mud and debris. Plus, the tires have extra sidewall ribs and an advanced tread compound for added durability out on the trail, along with a step-block groove configuration to increase the surface area and improves drainage.

The hub conversion kit includes a set of Rugged Ridge manual locking hubs, inner and outer Alloy-USA axle shafts, ½-ton capacity aluminum internal mounting hub, U-joints, machined front brake rotors, bearings, seals and hardware. Everything you need to upgrade your rig and prepare it for the trail. Maximum recommended tire size is 33 inches. Rotors are five studs on 4.5 inches.

The great off-road traction provided from the Yokohama mud-terrains created an easily overlooked issue in regards to the 20-year-old OEM axles and u-joints that could be twisted or broken from the added stress on the trail. To avoid the possibility of future trail repairs or tow-strap pushing, Barnes decided to preempt possible problems with a chromoly front axle and manual (freewheeling) hub kit, and he decided to turn to Summit Racing for the one-stop shop. Alloy USA’s Manual Locking Hub Conversion Kit for ‘84-‘06 Jeep Cherokee/Wrangler XJ/YJ/TJ/LJ models (P/N: ALY-12198, $1,587) is the perfect kit to convert a Dana 30 to freewheeling, with new very strong front axles, U-joints, bearings, seals, and brake rotors thrown in. Please make note: This kit is for the Dana 30 axle only, and it won’t work on a Rubicon Dana 44 axle.

This heavy-duty differential cover from Rugged Ridge is designed to protect your differential and all its working parts for as long as you own your vehicle. These indestructible covers have been “44-caliber tested”—if they can take a bullet at point-blank range, then they can handle all of the abuse that the trails have to offer.

The Alloy USA chromoly axles make a lot of sense, but why add manual hubs to your front axles? For several reasons, especially if you’re a commuter and the Jeep is your daily driver: Improved highway gas mileage, reduced front driveline wear and tear, easier steering effort, and some say reduced front tire wear. When the hubs are disengaged the front tires merely spin on the wheel bearings. The front axles, the front ring and pinion, and the front driveshaft are no longer spinning. They now just ride there, waiting until you engage the hubs and shift into four-wheel drive.

Discount Tire Co. (Kingman, Arizona) mounted the Yokohama Geolandar M/T 33x12.50-15R directional tires. These tires can churn through the deepest of mud and grab solid rock with ease because they feature beefy, deep tread lugs of very large proportions. The M/T tires are available in several different sizes, from 29 inches up to 40 inches in diameter.

For decades, four-wheeler manufacturers offered optional freewheeling hubs—some manual and some automatic—which were nearly always accepted on the option list. Then full-time four-wheel-drive transfer cases became all the rage, but they were gas guzzlers and weak links when it came to the more extreme trails, so enthusiasts quickly went back to selectable transfer cases. However, in most cases, the freewheeling hubs had gone the way of wind-wings and were lost in the process. Nowadays, hubs on new vehicles are few and far between—found almost exclusively on large, heavy-duty trucks.

Having learned to wheel in military Jeeps—I stuck a Jeep for the first time in 1958—I was totally unfamiliar with selectable hubs when I first started Jeeping as a recreational activity. In the early ‘60s, after chasing a dirt bike up and down trails for about two hours in a stock 1946 CJ-2a—no top, no doors, no roll bar, no seat belts, and the windshield removed—I stuck it in a deep ravine. We dug out the rear bumper and moved to the front bumper when I noticed the big chrome things in the middle of the front wheels. Since its lever was marked “2WD” and “4WD,” I twisted it to “4WD,” jumped in the Jeep and drove easily out of the ravine. I’ve been a freewheeling hub fan ever since!

After safely supporting the Cherokee, remove the tires and brake calipers. Set the tires aside and hang the calipers out of the way on wire. Don’t allow the calipers to hang on the brake hose, as it may damage the hose. Remove the brake rotor, hub bearing assembly, axle, and dust shield on both sides. None of these items will be reused.

After assembling the two axles a quick comparison of the two styles shows how different the two designs are, with the new axle having a much stronger and more reliable U-joint. Also make note that each side of the U-joint is equipped with a grease fitting to ease future maintenance.

Carefully slide the two assembled axles into the housing. Make sure that you don’t damage the grease seals as you insert the axles, and also make sure they’re properly seated in the differential.

Installing this conversion kit is not an easy two-hour task that anyone can do at home. You’ll need sufficient experience, a full set of hand tools (including a good torque wrench that measures foot-pounds), and a floor jack and jackstands (or a lift). If you know what you’re doing, the kit will take you six to eight hours to complete, and you may need a friend to assist. Your first step is to thoroughly read the entire set of installation instructions. The second step is to carefully check the package’s contents against the content list on page 8 of the instructions. Since the bearings and bearing races are so similar—as are some of the other components—you may want to write the IDs on all the parts (or their envelopes) with a Sharpie as you check them against the list (it’ll save you a lot of time during the install). Third step, read the instructions again.

Unpack the new conversion hubs. Ascertain which bearing race goes into which side and assemble. It may help to write the bearing ID on the hub to avoid confusion during assembly. Assemble both hubs.

Prep all four bearings by packing them with a good quality bearing grease. This is the time-honored method for bearing packing. With the grease in your palm, press the bearing into the grease until grease begins to squeeze out the top. Continue to press the bearing into your palm as you rotate it. This is the same way you repack the bearings when needed, except you keep pressing until new grease comes out the top to replace the old dirty grease.

Slip the bearings into their races. One on each hub will be retained by a grease seal while the other two go in just before the conversion hub is installed on the Jeep. (If you’re having trouble seeing the photos in the instructions, you can go to Alloy USA website and print out new instruction sheets.)

Very carefully tap the rear bearing grease seal into place (the metal frame is quite fragile). Make sure it is squared up with the conversion hub.

Use a block large enough to cover the entire seal so that it can be tapped in without bending or rocking.

The bearing should be installed in the back side of the spindle with the proper tool. Make sure the bearing is completely seated in the spindle. Now install dust seal; the open side of the seal goes inward toward the bearing.

Install the plastic fiber washer on the inward side of the spindle, slide the spindle over the axle shaft, and bolt the spindle onto the differential housing using the original bolts. Use Loctite on the bolts and torque them to 75 lb.-ft.

The wheel studs hold the rotor and conversion hub assembly together. Being careful not to damage the studs’ threads, press them from the back side of the rotor, securing it to the hub. Use an alternating pattern when pressing in the studs.

Carefully inspect the threads on all the studs to make sure the threads aren’t damaged.

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