2004 Nissan Titan Dana 80 - Four Wheeler Magazine

There comes a time when you simply know your axle is too weak for the tires you are running. That time came for us while prepping the Mega Titan for a trip to Central California's Pismo State Beach for some sand-dune running. Like we always do before a trip, we popped the differential covers of both Pro Rock 60 axlehousings to inspect the gears for chips or other signs of damage. We'd noticed a slight ticking sound as the guys at Triple-X Traction spun the tires with the truck on jackstands. At this point, we were forced to admit that we had some type of issue. Once opened up, the oil drained out to reveal several broken teeth on the pinion gear in the rearend. Much to our dismay, this meant our 4.56:1 gearing was not going to survive against 46-inch tires and 400 hp. Additional beef was in order. So we phoned Dynatrac to see what they thought of our problem.

At first Dynatrac's technician thought we were joking about damaging a 4.56:1 Dana 60 pinion gear with just 400 hp; then we dropped the 46-inch-tire surprise on them. The conversation quickly led to a discussion about how we used the vehicle. As soon as the words "crushing cars" and "30-minute burn-out" were announced, the technician told us our only option was the Pro 80. The idea that we could step up to a Dana 80 to solve our issues made us giggle. Not only would a completely new axle assembly allow us to fix a potentially weak link on the vehicle, but it would also enable us to convert the 20-plus-foot long Mega Titan to rear steer. Follow along as we showcase the buildup of the ultimate Dana axle.

1. This is where a Pro Dana 80 axle begins life. The nodular-iron centersection is machined to exact tolerances. We weighed our unit just to see to how heavy it was. We weren't surprised to find out the completed centersection weighed 122 pounds by itself. That's almost 40 pounds more than a Pro Rock 60 centersection. The big difference between the two, aside from the overall size, is the webbing thickness. The increased webbing adds significantly to the rigidity of the larger centersection.

2. Here you can see the physical difference between the actual axletubes of a Dana 60 and 80 axle by Dynatrac. The Dana 60 tubing is 31/8 inches in diameter and 1/2 inch thick, while the larger Dana 80 tubes are 3 5/8 inches in diameter and 9/16 inch thick. This added strength should enable the Mega Titan's new rearend to survive a considerable beating without issue.

3. Step 2 in the process was to press the inner Cs onto the axletubes.
4. With the inner Cs pressed in place, the next step was to weld the Cs in place.
5. Check out the sweet welds the Dynatrac technician laid down. Part of his secret for this is the rotational jig that slowly rotates the tube as it is welded.
5. Check out the sweet welds the Dynatrac technician laid down. Part of his secret for thi

6. We had these lower link brackets made prior to our appointment with Dynatrac. Twisted Metal Fabrication of Sacramento cut these from 3/8-inch steel sheet material. We did this so that the brackets could be installed on the axletubes prior to them being installed in the centersection. That way, the brackets could totally encompass the tubes, adding significant strength to the lower link mounts.

7. Here you can see the new Yukon 5.13:1 gearset (Dude, it's about time!-Ed.) fitted to the new ARB Air Locker sourced for the project.
7. Here you can see the new Yukon 5.13:1 gearset (Dude, it's about time!-Ed.) fitted to th
8. The next step of the assembly process was pressing the axletubes into the centersection. Once pressed in place, the technician performed a series of rosette welds to secure the centersection to the axletubes.
8. The next step of the assembly process was pressing the axletubes into the centersection
9. After the housing cooled down, it was moved to a cleaning area where it was scrubbed down to ensure it was free of debris. Once dry, the exterior was given a thick coating of black enamel paint to protect it from rusting. Next, the assembly technician started the process of setting up the ring-and-pinion. Once the gears were set up properly, the ARB Air Locker was bench-tested for proper operation.
9. After the housing cooled down, it was moved to a cleaning area where it was scrubbed do

10. Due to the fact that this rear axle was going to be a rear-steer application, we opted for another set of Longfield Super Axles. These axles are the cat's meow when it comes to strength. Made from 4340 chromoly, these CV-style bells offer 45 degrees of bind-free steering. The axleshafts are 35-spline units made from 300M tool steel. These shafts come with a lifetime warranty against breakage as long as you are running less than a 47-inch tire. We've had great luck with these shafts in the front of the Mega Titan thus far.

11. With the axleshafts in place, the next step was to assemble the outer ends of the axle. This includes the spindles, bearings, and brake rotors.
11. With the axleshafts in place, the next step was to assemble the outer ends of the axle
12. Next, the rear differential cover was installed. A thick bead of RTV silicone was used to seal the cover.
12. Next, the rear differential cover was installed. A thick bead of RTV silicone was used
13. Once the complete Dana 80 was ready to go, the technician serialized the housing to ensure ownership. This also allows us to refer back to the build sheet if we ever need to. Dynatrac keeps a paper file on every axle they produce.
13. Once the complete Dana 80 was ready to go, the technician serialized the housing to en

14. A complete rear axle isn't happy without a truck to go into. So we took both the housing and the Mega Titan down to Seaside, California, where master fabricator Toby Lavender and his crew at Triple-X Traction could finish the job. Here you can see Toby's crew unloading the truck from our trailer.
14. A complete rear axle isn't happy without a truck to go into. So we took both the housi
15. With the housing placed under the truck, out came the plumb bobs and measuring tape. Once it was centered under the rig, Toby began figuring out how to mount the upper link brackets to the top of the housing. Lucky for us, the rear driveshaft had plenty of slip to accommodate the added length of the Dana 80 pinion.
15. With the housing placed under the truck, out came the plumb bobs and measuring tape. O
16. In a few hours' time, Toby started welding up the new mounting brackets for the axle.

17. This shot shows the beautiful truss system Toby came up with to secure the upper link mounts. The 1/2-inch-thick plate was rosette welded to the Dynatrac axle truss.
17. This shot shows the beautiful truss system Toby came up with to secure the upper link
18. This is the latest-generation ARB air compressor. Notice the anodized aluminum fin structure surrounding the air tank. This helps keep the compressor cooler. Toby mounted this unit near the batteries, just behind the cab of the truck.
18. This is the latest-generation ARB air compressor. Notice the anodized aluminum fin str
19. This is what the axle looked like when we left the shop for the evening. Notice the uniformity in the welds surrounding the upper link mounts. A simple but classy flared hole was added to each upper link mount. We love these artistic touches. Next time, we'll cover the rear steering system and report on how the Pro 80 holds up in the back of our Mega Titan.
19. This is what the axle looked like when we left the shop for the evening. Notice the un