front Spider 9 Buildup Trail Buggy Spider 9 Axle - bolted Inner Knuckle - Photo 10480145

Back to Article

With the shafts installed, the unit-bearing assemblies were bolted to the outer knuckles, and then those were bolted to the inner knuckles. As a side note, Spidertrax also makes its smaller Ultimate 60 (55-pound) knuckle using the same construction but sized to fit U-joint axleshafts and accommodate 50 degrees of steering angle

129 0809 32 z+front spider 9 buildup trail buggy spider 9 axle+spider 9 axle

129 0809 32 z+front spider 9 buildup trail buggy spider 9 axle+spider 9 axle

Cary started with a Spider 9 raw housing. The housings come in centered and offset versions and are 65 inches in width. Each housing includes third-member mounting hardware and a blingy anodized-aluminum fill plug.

Here you can see the backside of the centersection of the housing that's created from a single piece of 1/4-inch-plate steel. Where the centersection meets the axletubes, the joints are welded inside and outside to ensure plenty of strength. Long-term field testing and competition use have proven these assemblies to be up for taking a beating.

Axletubes are 3 inches in diameter and can be ordered with 1/4- or 3/8-inch-wall-thickness tubes. Full width weight is a svelte 60 pounds for 1/4-inch-wall and 80 pounds for 3/8-inch-wall. Cut your blank housing to your chosen length, or Spidertrax can provide one to your exact dimensions.

This assembly is the Ultimate 1550 knuckle which is fabricated from an assortment of cold rolled steel plate and machined pieces. The components are laser-cut and CNC-formed before being jigged and final welded. This entire assembly weighs only 70 pounds, which is much lighter than any cast Dana 60 assembly.

Here you can see the inner knuckle half. In the center is a machined piece that mates to the outer diameter of the axletube where it is welded in place. These pieces are beautiful components and the craftsmanship superb.

The outer knuckle half sports a four-bolt pattern that mates to a unit-bearing assembly, providing the spindle and wheel hub.

The knuckle uses a spherical ball and race pair that is more compact than a traditional ball joint, while improving overall strength. A pair of these spherical assemblies has an axial load rating of 16,000 pounds.

The knuckle halves are joined with a pair of 3/4-inch shoulder bolts and hardened cinch nuts. We were completely amazed at how easily these pieces slipped together and bolted up. There was no prying or tapping in place. They simply slid one over the other.

Up top, the outer knuckle half has been machined to accept a mating steering arm. Four bolts, plus a machined keyway, ensure the steering arm is well anchored on the knuckle and won't loosen or shear under extreme loading.

To mate the knuckle to the wheel, Spidertrax uses an upgraded Ford F-450 1-unit bearing assembly. However, they CNC-machined it to accommodate beefy 35-spline axleshafts. Several wheel bolt patterns are also available.

Talk about sharp steering. This assembly has the capability to turn at a tight 60 degrees of steering angle, a truly impressive turning radius that is limited only by the axleshafts you choose.

More bling parts in anodized aluminum include the Spidertrax High Performance Oil Seal, which is guaranteed not to leak, and these cool CNC-scribed hub covers.

Once an axle track width was decided upon, the axletubes were cut to length in a chop saw. In our case, the axle was being installed on a rock buggy, so link mounts were built to position the axle. Then, the knuckle assemblies were bolted together loosely, and the caster angle of the knuckles-in relation to the third member and axle mount position-was determined.

The backside of the inner knuckle was welded to the axletube, and then a second full-circle weld was completed on the other end of the knuckle.

In preparation for the final assembly, the oil seals were installed from inside the axlehousing. Their supple material and snug fit should ensure the oil stays inside the pumpkin under extreme articulation.

Here's the high-pinion third member that will be used in the axle. It's a fully built True Hi9 assembly from Weivoda Auto. The housing is heavy-duty nodular cast iron and uses chromoly bearing caps. The reverse-cut gears are made by Richmond Gear and use a third (pocket) bearing at the pinion head for greater strength and reduced pinion deflection.

This third-member housing also includes a device (unique to the Hi9) for ring-gear support. The adjustable bolts shown here are used to support an anti-deflection thrust block that controls ring-gear side load to keep the ring-and-pinion in proper mesh under severe torque loads. Also in this assembly a full spool was used as the locker mechanism.

A forged 1350-series yoke was chosen to provide the strongest possible connection to the driveshaft. A Daytona-style pinion support is used on all Hi9s. This offers a larger pinion bearing and improved oil flow and lubrication.

Here, the stout third member is slipped into the completed axlehousing linked to the buggy chassis. You can see how much ground clearance the high-pinion driveshaft will have for this setup.

One final thing that was added to help protect the third member and provide a smoother rear face is this trick diff skidplate from Blue Torch Fabworks. It attaches with some of the axlehousing bolts and three of the pinion support bolts.

An underside view of the finished axlehousing shows the protection provided by the third-member skid. This is one beefy setup.

The axleshafts of choice were Longfield Super Axles using full 35-spline components manufactured from hardened 300M material. The inner and outer axleshafts are individual pieces splined on each end, and the CV-joint bell is a third, separate component made of 4340 chromoly.

Here you get a glimpse of the backside of the Birfield joint, however, full of grease from the supplier. This super-sized CV joint is comprised of six 7/8-inch ball bearings made to allow for smooth power transfer at all angles and can provide a steering angle of 45 degrees.

The open end of the Birfield is enclosed in this formed red plastic boot. It keeps the grease in and the dirt and water out. Slide it back and a zerk fitting is revealed, should you need to add a squirt or two of fresh grease.

The shafts were installed in the completed axlehousing that at this point was link-mounted to the buggy and ready for internals.

With the shafts installed, the unit-bearing assemblies were bolted to the outer knuckles, and then those were bolted to the inner knuckles. As a side note, Spidertrax also makes its smaller Ultimate 60 (55-pound) knuckle using the same construction but sized to fit U-joint axleshafts and accommodate 50 degrees of steering angle

Spidertrax steering arms mount to the top of each knuckle using four or six bolts. Additional shear strength is provided with the machined slot (arrow).

Warn floating-hub drive flanges were used in the Ford unit-bearing assemblies, providing a constantly locked front axle for this trail-only rig. Spidertrax now manufactures its own heat-treated 4340 versions as well.

With the hub assembly complete, each wheel hub was closed with a Spidertrax aluminum cover plate.

Spidertrax sells some very cool brake components, including Wilwood billet calipers and some super-trick lightweight rotors that utilize aluminum hats. For this application, Cary required a rotor that would fit inside a 15-inch wheel, so he chose to use an OEM Chevy 3/4-ton rotor.

Calipers used were Oldsmobile twin-piston floating units. These were bolted to tabs that were welded to the outer knuckle. Steel construction of the knuckle easily permitted this methodology. Spidertrax carries custom mounts for the Wilwood calipers if needed. With the axle assembly complete, the rig was ready for some hard-core trail action.