Transformer - Part 4: Manual Hubs & 8.8 Axle Swap

Transformer Install – Part 4: Manual Hubs and Explorer Rear Axle Swap

By Jim Allen

(From Off-Road Adventures Magazine)

We complete the Ranger’s drivetrain improvements in this installment by performing a rear axle swap and updating the front hubs. Last time, we finished up the gear swaps and locker installs This time, we want to show how the similar-but-not-the-same Explorer axle was installed and show the brick-simple addition of manual Warn hubs for strength and reliability.

At purchase, one of the Ranger’s original automatic hubs was inop… a common occurrence for hi-miler Rangers. Warn’s hub conversion kit eliminates these weak and troublesome automatic hubs. The kit is fairly inexpensive and easy to install. According to Jim Oaks and many other Ranger experts, the automatic hubs are a serious liability on TTB Rangers and their replacement is close to “Job One” for a trail buildup at any level. Not all Rangers came with the automatic hubs, usually those with the electrically actuated transfer cases.

The late TTB Rangers (’90-97) with 4.0L engines use an 8.8-inch rear axle, which sounds gnarly for a compact truck, but in fact it’s the wimpy version with 28-spline axle shafts and drum brakes. The shafts are no bigger than the 7.5-inch Ford axle used behind smaller engines. The 28-spline 8.8 unit holds up OK with tires up to 33 inches, but offers almost no strength reserve in hard work situations. The general swap tips you will see could apply to replacing a 7.5-inch Ford with an Explorer axle.

It’s possible to upgrade to 31 spline shafts in the old housing by changing the necessary internal diff parts (31-spline side gears or a 31-spline locker) and ordering custom shafts. Still, many owners find the swap route a more cost effective choice and use complete ’95-01 Explorer rear axles, which are common and cheap. These units come with disc brakes, have larger axle tubes (3.25 vs 3.0-inches) and 31-spline shafts. The other advantage is that, because of the disc brakes, the dangers of losing a wheel if the axle shaft breaks is reduced. How?

All 8.8s use c-clip axle shafts. On the drum version, should you break a shaft, the wheel, brake drum and shaft will simply slide out of the tube. The truck is virtually immobile at that point. The caliper and brake rotor on the disc brake axle will keep the shaft from sliding out. No, you can’t drive it home at 70 mph, but at least you can slowly move the rig to a better location for repairs, or onto a trailer.

Oaks scrounged up a ’95 Explorer rear axle, did the prep work and his master welder buddy “Ozzy” Osborne assisted in torching off the old mounting brackets, and welding the new spring perches and shock mounts onto the 8.8 housing for the swap. The driveshaft required no changes. The e-brake cables will require changes, but in our case, Oaks opted for a hydraulic line lock, so we can’t detail that for you, but other owners have adapted the Explorer cables to the Ranger and Lokar Performance Products has universal cables.

In most cases where rear drums are changed to discs, the master cylinder should be changed to an Explorer disc brake unit. According to Oaks, the exception is when the Ranger has rear ABS brakes. In the case of rear ABS, the master cylinders are the same. Our Ranger was set because it had rear ABS.

As a final touch, Oaks added the TRS heavy duty diff cover to the package. This cover is made of 1/4 inch plate and was designed by Ranger enthusiasts for Ranger enthusiasts.

Warn Manual Hub Install

Tools Required:

2-3/8 inch and spanner type
spindle nut sockets
torque wrench

Wrench Rating:

1. The old and the new. The hub comes separate from the spindle nut kit. You can buy the nuts and washer from Ford also or from Warn. These are the same parts as used on the Dana 35 trucks with manual hubs.

2. Remove all the old hub parts to the outer bearing. You will need a 2-3/8 inch spindle nut wrench to remove the old nut. Now is probably a good time to clean and repack the wheel bearings and replace the hub seal. In our case, new brake rotors were installed.

3. Install the inner nut (the one with the guide pin). These nuts require a four-prong spanner type spindle nut wrench. Tighten the nut to 35 lbs-ft while rotating the hub to seat the bearing. Back the nut off 90 degrees (about 1/4-turn).

4. Install the lockwasher. The slotted part engages in the spindle and the guide pin should engage in one of the holes. If not, try flipping it over. If still a no-go, you may slightly tighten the nut enough until the pin engages a hole.

5. Install the outer locknut and torque it to 85-135 lbs-ft.

6. You will need to reinstall the thrust washer and c-clip from the automatic hub.

7. Install the new hub by slipping it over the wheel studs. The wheel holds the hub on. You’re done!

Explorer Rear Axle Swap

Tools Required:

Stick or wire feed welder
dial protractor
torque wrench

Wrench Rating:

1. There’s a 20-25 percent difference in strength between this Explorer 8.8 and the Ranger 8.8. The bigger 31-spline axle accounts for most of that, but the 3.25-inch tubes also help. The disc brakes are an overall vehicle enhancement. The TRS cover eliminates worries of the thin stock cover getting punched, plus it holds an extra quart of oil for cooling.

2. Here’s the at-home method of dropping and installing an axle. After supporting the vehicle with stands and letting the axle hang, use two floor jacks as shown to hold the unit up as you unzip all the attachments. Start with things like cables and hoses, etc., ending up with the u-bolts.

3. The Explorer axle mounts with the springs under the axle and the Ranger mounts in spring over configuration. The shocks also mount in different locations. After torching or cutting off all unnecessary brackets, Oaks uses a grinder to clean off the area where the new spring perch will be welded to the tube.

4. The Explorer’s perch to perch distance was the same as the Ranger’s, but the new perch needed to mount on the opposite side of the tube. Oaks left the old perch in place. Setting the pinion angle is vital to getting a vibration-free driveshaft. There are two ways to do this. If you know the correct angle (in this case 6 degrees, i.e. the pinion was angled up six degrees from the level of the spring perch), you can level the pinion and simply set the perch at six degrees using a dial protractor (cheap and available at Sears or other tool stores) and weld it into place. The other way is to actually install the axle with the perches loose and the u-bolts not fully tightened. Center the axle on the springs, hook up the driveshaft, rotate the axle inside the u-bolts until you get the right driveshaft and pinion angles, tack-weld the perches in place then remove the axle to do the final welds. This latter method also works with determining shock mount locations.

5. Welding the perches and the shock mounts must be carefully done so as not to overheat the tube and possibly distort it. The best way to do that is to weld about an inch at a time, let it cool then weld another inch on the opposite side and let it cool again. Repeat this until you have it fully welded.

6. The new axle bolts up just like the old one, though you will need new 3.25 u-bolts and spring plates to replace the Explorer’s 3-inch pieces. The shock mounts were welded on after the axle was installed so as to get the correct position. The brakes were installed after the axle was installed using new or rebuilt parts from a local auto parts store.