The differential cover is of vital importance on the trail. Crack, dent, loosen, or flat out smash this cover on a rock and you could be in for a very long night. The cover keeps the life-saving fluid inside the differential. If you loose the fluid you’re stuck. I have even seen covers smashed so badly that the ring gear could not even move!

Several manufactures have come up with solutions to this issue, but I have only seen one that protects against almost all possible trail hazards.

Why Poison Spyder Customs?
As always, I like to explore all of the options before making a decision on a product. Poison Spyder Customs are well-known for their rock buggies and competition rigs. With all the thought that goes into those machines, it seems that the concept of the rock rings is almost obvious.

The second problem became the cover bolts. They received very little protection. I shaved them so badly on rocks that when it came time to remove them we had to use some locking pliers. Fortunately, we were able to get them out with a little work.

The last issue with this style is that they only bolt to the lower part of the differential. With a hard enough impact this acts as a lever to extract the bolts and the cover. This, alone, seems like it would increase the risk of a problem and not lessen it.

Option “C”
This option is of similar design to Option B but covers the entire diff cover with tubular protection. This could eliminate the risk of peeling off the cover from leverage but it is still bulky and leaves the bolts open to some risk. This design only works on rigs with lots of axle clearance. In fact, the full mask of tubes would even interfere with my gas tank in the rear of the TJ.

The Rock Ring installed on the Dana 30 front axle.

Option “D”
Maybe we should we just call this one the “Poison Spyder Option.” The rock ring is a ¾” thick ring of steel that completely covers the lip around the differential cover. It incorporates a ¼” center skid plate to protect the center section of the cover while remaining low-profile to clear rocks and vehicle components. The stainless Allen head bolts replace the factory bolts and sit flush inside the rock ring. This keeps them totally out of harm’s way.

The thickness of the ring itself ensures that it can take a beating without letting the cover peel away. The rings matched up perfectly to the curves of the diff cover and bolt to all the holes to prevent it from becoming a lever. The low-profile and flush-mounted bolts make the cover actually less likely to snag on something than with no protection at all.

This option is an excellent idea for both the front and rear differential of your rig. Poison Spyder Customs makes them to fit all of the most-popular axles. We installed them on the front Dana 30 and the rear Dana 35 on Project Cross Trainer. This is added insurance that our daily-driver will make it to work the day after a good trail.

The Rock Rings sell for $128.50 and after using them for several months, we are confident that they are one of the smartest investments you can make for your trail rig - especially if you are clearance-challenged. Their low-profile, great-looking design is not only unique but has proven strong enough to withstand all the abuse we could throw at them during our long-term testing.

Installation
The Poison Spyder Customs Rock Rings are incredibly easy to install. You don’t even have to remover your diff covers. However, it’s probably been a while since you swapped your fluids, so now is the perfect time.

1. Take out the differential cover bolts. The silicone gasket will keep the cover in place.
2. Bolt on the Rock Ring with the new bolts to factory torque specs for your rig.
3. You’re done! Go play harder now!