The factory Toyota rear axles are a semi-floating design. In this design, the load is spread over 2 components. One is the wheel bearing, the other is the axle shaft itself. The load taken by the axle shaft then gets transmitted to the carrier bearings inside the differential. These axle shafts are also only held in by the press fit bearing on the axle shaft. When this bearing wears out, there is nothing left to hold the entire assembly to the housing; hence it promptly leaves the vehicle…wheel, axle shaft and all.
Should an axle shaft break, the bearing will hold the axle in for a short time, until the wobbling, and twisting force destroys the bearing. Since the wheel bearings were never designed to take a twisting force, the bearing fails shortly after the axle shaft breaks.
Drum brakes leave something to be desired as well. They fill up with mud, water and other contaminants easily, quickly destroying the shoes and drums. The adjusters wear out quickly, lessening their effectiveness and longevity.
On a full-floating axle design, the load on the wheel is placed 100% on a pair of wheel bearings. The axle shaft is only used to drive the wheel, not take the weight of the vehicle. If a wheel bearing fails, the wheel does not leave the vehicle because the bearings are tapered roller, and held on by 2 spindle nuts. The wheel/hub assembly can wobble, significantly, and the wheel still will not come off. Also, with the full-floating design, an axle shaft can fail, and will only affect drive to that wheel. Should an axle shaft break, the pieces should be removed, but the hub assembly, bearings and brakes will not be affected.
The full-floater conversion kit also integrates locking hubs on the rear axle, which can be unlocked for flat-towing the vehicle. DO NOT USE WARN, MILEMARKER OR OTHER AFTERMARKET LOCKING HUBS!! These hubs are MUCH weaker than the Aisin hubs and our Drive Flanges. They also do not allow proper spline engagement into the differential, nor do the aftermarket hubs use cone washers, which are vital to retaining the lock hub to the wheel hub.
With the disk brake conversion, mud and water become much less of an issue, as disks self-clean very quickly and efficiently.
We often get asked "What other benefits does a Full-Floating axle have, why should I convert?" Well, like they say, a picture is worth 1,000 words. Here's the left rear axle shaft in our Tacoma, after just 3 trail runs (see pics). This runout translates to about 3/8-1/2" wobble in the tire. This not only wears tires unevenly, but rapidly destroys a drum or disk brake (imagine a rotor with .120 runout!) and it eats wheel bearings for lunch. With a Full-Floating axle, this simply cannot happen. And no, the truck was not jumped, or hopped on obstacles.
Please note, the "Supra" version in the article is a little different than the kit currently. The current version uses solid axle hubs and spindles, with matching calipers and rotors. Caliper and rotor used can be vented rotors, and larger IFS calipers, the same upgrade commonly done on solid axle font ends.
- Full float axle shafts
- Snap rings and Axle shaft seals
- Adapter ring with integrated caliper mounts and bolts. (This connects the spindle to the stock housing)
- Seal holder (presses into the back of stock spindle)
Q: Do I need a larger master cylinder to push enough fluid to the new calipers?
A: No, the calipers are a great match with the factory M/C. The pedal feel is almost identical to properly setup drum brakes, except the truck stops quicker.
Q: Do I need a Residual Valve?
A: No, because there is no rotor run out (wobble). With other disk brake kits, the play in the wheel bearing causes the rotor to wobble. This play pushes the caliper piston back into its bore. The residual valve maintains a small amount of pressure to the calipers, to prevent the piston from being pushed very far back into its bore.
Q: What’s involved in installing a Full-Floater Conversion Kit?
A: All that is required is to remove your stock axle and brakes. From there, start bolting on the new parts. There is no welding or cutting required. No special tools are required.
Q: Will the Full-Floater Conversion Kit work on a truck equipped with ABS?
A: On ABS equipped trucks the ABS must be bypassed. Please call for more information.
You Need to Supply:
- Factory wheel bearings for '79-'95 front axles (inner and outer)
- Factory hubs from '81-'85 solid axle truck
- Factory locking hubs from '79-'85 truck
- Inner wheel bearing seal.
- Stock '79-'85 front spindles
- Wheel studs (normally can be reused)
- Rotor to hub bolts (easily reused, 2 per side)
- factory spindle from front solid axle 79-85
- wheel bearing nuts, washer, and locking ring
- Essentially spindles out from a solid axle truck!
Kits Available for the Following Axles. PLEASE NOTE: Our Full Float Seal Holder will fit stock and Diamond Axle housings. We cannot guarantee the fit on other aftermarket housings.
- '79-'85 pickup
- '86-'95 pickup/4runner
- '95.5-'04 Tacoma/96-02 4runner
- '93-'98 T100
- '00-'04 Tundra
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I ordered this kit and the axles were back ordered from RCV. Amber was great! She kept me informed and I’m pretty sure they pestered the crap out of RCV to get me the kit before my thanksgiving trip. Thanks so much.