|
|
Beefing A Rear Axle & Adding Disc BrakesToyota Full-Floating Axle Install From the February, 2009 issue of 4Wheel & Off-Road By Johnny Kingfisher Photography by Christian Hazel, Fred Williams, Jeff Nasi
|
|
Far be it from us to leave a good thing alone. Although the Toyota 8-inch rear has been serving diligently underneath Toyota pickups for more than 15 years, it can still fail when used beyond its parameters. Fortunately, there are a few options available to increase strength, ranging from stronger axleshafts to complete axle assembly swaps. Around the middle of that cost range is the full-floater shaft conversion. Complete assembly swaps may appear as inexpensive on the surface, but can contain hidden costs. Such details as width, new spring mounts, brakes, and bolt-circle variances can quickly increase time and overall expense. For our money, we found a full-float kit and disc-brake conversion from Front Range Off Road Fabrication that gave us everything we needed at a reasonable cost. The kit from Front Range contains... The kit from Front Range contains the adapter brackets, custom axle seals, custom axleshafts, seals, brake rotors, flex brake line, proportioning valve, and all required fasteners. The heart of the kit is the machined-steel adapter ring that serves as the caliper mount as well as the spindle mount. The axles are manufactured from 4340 steel specifically for this kit and do not neck down on the carrier side like the factory units. A standard semifloating axle assembly layout consists of three primary components: the axleshafts, the differential with the ring-and-pinion gears, and the axlehousing. Each axleshaft has a flange on the end where the brake drum and wheel bolt up. The other ends are splined and insert into each side of the differential. The axle rotates on a bearing retained in the end of the axlehousing, and the axle itself supports the weight of the vehicle and transmits torque to the wheels. The full-floater axle design gets its strength by isolating the axleshaft from the housing with a spindle and hub, just like the front axle, to support the weight of the vehicle. The axle simply passes through the spindle to transmit torque to the wheels and is connected to the hub by a locking hub or drive flange. Overall strength is just one of the fruits of labor for this easy install. Should you break an axleshaft on the trail, the ability to remove the broken shaft and still make it home is like having a "Get out of jail free card" in your pocket. The key to this design is that the hub/bearing/spindle assembly is mounted to the axletube. This allows the wheel to operate as normal, regardless of the presence of an axleshaft. We took a weekend and some wrenches, and beefed our Toyota with a minimum amount of effort, and it was well worth the cost. Check out how our project progressed.  You will need to procure spindles,...  You will need to procure spindles, wheel hubs, and manual locking hubs from an '84-'89 Toyota 4x4 truck, and brake calipers and pads from a '79-'80 Toyota Celica or Supra. You can also try to order everything new, but if you do, be sure to order "loaded" calipers, which come complete with mounting plates and pads. As for the locking hubs, Superwinch, Warn, and Pro Comp each offer new sets or you can nab an '84-'89 pair from the salvage yard as we did.  Start by supporting the rear...  Start by supporting the rear axle with jackstands, then remove the wheels, brake drums, and brake lines. Remove the four bolts that attach the axle-bearing assembly to the housing and slide the axle out of the housing. Here's a tip: As you work on each side, raise it slightly higher than the other so that remaining oil in the housing tube does not leak out.  The adapter ring simply mounts...  The adapter ring simply mounts using the four bolt holes that held the axle-bearing assembly to the housing. Remove the inner axle seal and clean the mating surface with carb cleaner. Liberally coat the flange with a good RTV sealant, then mount the ring with the tabs towards the center and rear of the vehicle so that the caliper mounts will sit in the 1 and 3 o'clock positions as shown. Grease each end of the axleshaft and slide the axle into the tube.  Remove the factory axleshaft...  Remove the factory axleshaft bronze bushing from the used spindle by tapping it from inside out with a long steel punch. Install the Front Range seal where the bushing was. Grease the seals prior to installing the spindle on the axleshaft. This is crucial for any seal, as it will tear quickly before the oil arrives to lubricate it. Clean the mounting surfaces and lay on a bead of RTV as you did with the ring, and then install the spindle.  Clean out the interior of...  Clean out the interior of the used hubs, especially the bearing races and bearings. Better yet, get new races, bearings, and seals--it's always cheap insurance. Install the rotors in the kit onto the hubs and press in the new wheel studs. Be sure you get the wheel studs fully bottomed out rather than relying on your lug nuts to pull them down all the way.  Installing the hub and rotor...  Installing the hub and rotor assembly and locking hub is no different from your typical "remove and replace" procedure as on the front axle. Pack the wheel bearings and install the seals, then slam the assembly home according to the front axle specs, including the locking hub. We like the look of the stock hubs in the rear, just for the sheer fact that it confuses.  The calipers easily mount...  The calipers easily mount up to the adapter tabs with just the two bolts. The small aluminum block is used to adapt the emergency brake cable to the new caliper instead of the drum backing plate.  The existing steel brake lines...  The existing steel brake lines are now too long because they formerly stopped at the backing plate. If you have a flaring tool, you can cut and flare the end to the proper length. We gently made a loop to shorten ours and it worked out fine. If you do loop the tube, it's recommended that you fasten it to the old tab as shown to eliminate metal fatigue from vibration. Ideally a bracket should be used to retain the loose end of the rubber hose.  Bleed the brakes well and...  Bleed the brakes well and test out the braking bias by performing several quick stops. Should you need to install a brake proportioning valve, there's one included in the kit. It is mounted up by your master cylinder and requires no cutting or flaring of lines. Simply install it on the rear line from the master cylinder and then bleed the brakes. The valve will allow you to adjust how much rear pressure rise is sent to the rear brakes.  Now you're all set for the...  Now you're all set for the trail and you will look cool to boot. It should be noted, there are a few drawbacks to having a full-floater axle on your rig. Not only will you field questions as to why you have hubs on the rear axle of your rig, but your buddies will find that it's a great practical joke to unlock the rear hubs when you're not looking.
|
|
|
|
'Yota Bits
Check out Places to Find Toyota Performance parts, brought to you by the experts at 4-Wheel &...
more
|
|
|
Kamikaze Blue
Phil Bargman's '76 Toyota Land Cruiser is a mix of fine Japanese styling and strong American...
more
|
|
|
|
|
|
|
|