This tutorial will show you how we build our personal Team AtomicMods Team Car MR-02 ball differentials. The differential is probably the single most important element besides tires to get your car tuned to grip and accelerate quickly on the track.

As a base, we will use the all new Atomic Version II ball differential with titanium shaft. Even though this diff is smooth and probably the best out of the package, we're always looking for ways to improve existing products to get that little extra edge on the track.

It isn't hard to do the following modifications to your differential and the rewards are incredible! Installing ceramic bearings and sanding the differential rings are straightforward tasks that will make your differential feel as smooth and silky as can be. With smoother differential action, your car will be a lot easier to drive and this will allow you to turn faster, more consistent laps at your local track.

• Atomic Ball Differential
• Team Trinity On-Road Diff Lube
• AtomicMods 3/32 Ceramic Diff Balls
• Single 3x6x2.5mm Ceramic Bearing
• Atomic 43T Delrin Spur
• Hobby Knife
• Flat Nose Pliers
• AtomicMods 3000 Grit Polishing Sandpaper
• Paper Towels
• Water

The first step is to loosen the differential in order to prepare to disassemble. Hold the shaft as shown in the picture with some flat nose pliers and turn the adjustment knob counter clockwise. Don't remove the knob though. leave it slightly threaded so it doesn't fall apart.

Now that the diff is loose it should be easy to remove the e-clip holding the diff together. Use a hobby knife to push it off the groove by pushing the closed side of the clip away from the differential shaft. Be careful though, this little bugger may fly across the room it you are too abrupt.

In this picture you should be able to see the differential without the e-clip.

Pull the differential gear with everything stuck to it away from the shaft.

Once all the parts are separated, this is what your differential should look like.

On the right, we have the stock parts. On the left what we like to refer to as the "Good Stuff."

Wipe off the old grease from the differential rings with a clean paper towel. Do this to both rings.

Prepare the fine grit sandpaper by adding a little water. Water helps get a more consistent finish on the rings.

Sand the rings in circular motion until you can no longer see shiny or uneven spots on the rings. What you are trying to achieve is a flat surface to get more consistent differential action under load.

The rings should look nice and uniform. Notice the consistent "hazy" ring inside the actual differential ring. This is the part the ceramic balls will ride on and what we made flat.

Apply a tiny drop of lube to the back plate of the differential. This is used to simply hold the ring in place. Many people don't like doing this as they claim it will make the plates slip. The Atomic Version II differential has D-shaped rings, so this can not happen.

Slide the ring and set it in place, matching the notch on the plate and the ring. Make sure you have the side that we sanded facing the Spur Gear.

Take six of the 3/32 ceramic balls and place them in the palm of your hand and put a couple of drops of lube on them. make sure your hands are clean when you do this so you don't contaminate the differential.

Nice and goopy! Don't be afraid to get a little messy.

Insert the coated Ceramic Balls into the Delrin Spur Gear. If the balls are coated thoroughly, using a hobby knife to drop them in makes it very easy.

Now coat the the differential ring with lube.

Slide the diff spur gear over the shaft and set it aside.

Take the differential front plate and repeat the same lube technique that you did with the back plate.

You will again install the differential ring with the sanded side facing the spur gear.

Once again, coat the side facing the spur with plenty of lube.

Slide the front plate with the differential ring over the shaft.

Take the new 3x6x2.5mm Ceramic bearing and install it on the front plate.

Take the new 3x6x2.5mm Ceramic bearing and install it on the front plate.

Use your flat nose pliers to "snap" your e-clip into the slot. This should not take a whole lot of force.

You can now re-tighten the differential. Use the flat nose pliers and tighten the knob counter- clockwise until it is "finger tight". Take a look at the notes at the bottom of the page for adjustment tips.

Here you go! A fully built and blue printed competition differential identical to the ones we use aboard our cars.

Now that you have your Ultimate Diff, here are some tips on how to adjust it. Typically you want to wait until after the the first run to adjust it (unless it is slipping terribly and by this I mean, it takes a long time to spool before it takes off), since your differential will free up tremendously as they break-in and settle. So always inspect it after the first run. We usually adjust a differential to the point where it is on the "verge" of slipping, but doesn't. This is different depending on the surface you are running on and the power applied to the differential. Higher grip surfaces require tighter differential settings and cars with non-FET stock motors can run slightly looser differentials than those with hot modified motors.

Ultimately you want your diff to be adjusted to the point where it accelerates the fastest while still maintaining good grip through the corners. A tighter differential will give you more on-power steering especially coming out of the corners. Careful though, if you over tighten your diff, the car will want to spin out when you get on the accelerate. In the same token a looser differential setting will give you more off power steering. The problem that can be faced running too loose of a diff is that it will make the car sluggish accelerating out of the corners and in a straight line.