spider 9 Axle Housing Buildup - third Member - Photo 33226989

Back to Article

The Ford 9-inch drop-out third member was assembled by the master differential technicians at JT's Parts & Accessories/Justdiffer-entials.com. The nodular-iron race drop out housing offers increased lateral and vertical web gusseting for extra strength. The heavy-duty 1350 pinion yoke and aluminum Daytona pinion support further increase strength.

Tri County Gear in Pomona, California, completed the build of our Spider 9 axle housing using components from JT’s Parts & Accessories, Nitro Gear & Axle, Moser Engineering, and Teraflex. The performance 9-inch rear axle assembly will be installed under a prerunner/rock-crawler Jeep Cherokee.

The Ford 9-inch drop-out third member was assembled by the master differential technicians at JT's Parts & Accessories/Justdiffer-entials.com. The nodular-iron race drop out housing offers increased lateral and vertical web gusseting for extra strength. The heavy-duty 1350 pinion yoke and aluminum Daytona pinion support further increase strength.

We finished the assembly of the Spider 9 using a set of 35-spline Moser Engineering axle shafts and a Teraflex disc brake kit. The Moser 'shafts use large 1/2-20 lug studs.

Jason Bunch, owner of Tri County Gear, began the axle build by determining the necessary axle tube length. We had ordered the Moser axle shafts to meet the desired wheel mounting surface (WMS) to wheel mounting surface dimension.

Here, Jason measures the depth of the Nitro spool to determine how far the 'shafts will extend inward.

Once it was determined how far the 'shafts would extend in to the spool...

...Jason marked the location on the 'shafts.

The axle shaft is shown fully engaging the splines within the spool.

With the depth of the axle shafts within the spool determined both the left and right side axle shafts were inserted in the spool so WMS to WMS measurements could be taken. Using these figures we were able to determine the necessary axle tube lengths.

The Spidertrax Spider9 housing is 65 inches wide. We needed to shorten the tubes to create a 60.5 WMS to WMS dimension. The Tri County Gear crew took careful measurements to accurately determine the proper tube length. It's always best to measure twice (or more) and cut once.

To ensure a straight cut, a straight edge was employed to make sure the chop saw was in proper alignment with the axle tube.

After careful measurements, the 3 1/2-inch-diameter by 1/4-inch-wall axle tubes were cut to the proper dimensions.

The freshly cut tube ends were cleaned up inside and out.

The beveled edges on the tubes will help it properly mate up to the Moser Big Ford housing ends.

Tri County Gear uses a cut-away 9-inch drop out jig to accurately place the housing ends. We could have used the Nitro race housing drop out but we would have had to disassemble the gears and spool set up to do so.

With the cut-away 9-inch drop out jig in place a solid straight bar was inserted through the length of the housing. This will ensure that the housing ends are in phase with the center section so the axle shafts will be properly located.

Careful and repeated measurements were taken to ensure that the Moser Big Ford housing ends were accurately placed.

The correct rotation of the housing ends is also important so they sit in phase with the housing center. The Tri County Gear team used a level gauge to determine placement.

The Moser Big Ford housing ends were capped and clamped in place once their locations were determined. After some final measurements to verify accuracy the ends were tack-welded in place.

After more measuring to ensure that the housing ends were accurately placed they were welded to the tubes.

After cooling the welds were cleaned up and the 9-inch drop out jig and solid straight bar were removed.

The Spider 9 housing was then thoroughly cleaned and painted.

With the Spider 9 housing ready to receive parts the Tri County Gear crew began pressing in place the axle shaft bearings and seals.

To ease in assembly the Tri County Gear crew used a dab of 3M yellow glue to hold the bearing retainer ring to the bearing.

Black silicone was applied to the third member mounting surface. The Spider 9 housing is drilled and tapped so the third member drop out can be bolted up to it. The drop out is retained with bolts provided with the Spider 9 housing.

The Nitro third member drop out assembly was bolted up to the Spider 9 housing using the provided bolts.

The Teraflex brake backing plate was positioned on the Moser Big Ford housing ends and the assembled axle shafts were inserted in the axle tubes.

The Moser axle shaft retainers were then bolted to the housing ends, sandwiching the brake backing plate in between.

As a final step of the installation the Teraflex rotors and calipers were installed, along with the Moser 'shaft logos.

The completed Spider 9 axle assembly will offer strength and versatility to our Jeep Cherokee prerunner/rock-crawler. The clam-shell design of the housing offers a smooth bottom and backside that will slide across obstacle rather than hanging up. Check out the cool aluminum Spidertrax oil fill cap.

We like the simplicity of the Teraflex brake kit. We had considered using a more custom brake set-up but after some thought we liked the advantage of being able to pick up replacement parts at our local (or remotely located) auto parts store.

The Spider 9 axle housing offers a slim design that will work well with the rear mounted fuel tank in our Cherokee.