The differential is what helps the spinning motion coming from the engine get transferred to the tyres. This is done with the help of many other components too including the CV joints. When a suspension lift is done, the CV shaft gets lifted too which makes them sit angled towards the wheel hub assembly. This is not good for the joints and definitely not for the assemblies, which is why you should use a diff drop kit to lower the differential. This helps align the CV joints with the hub assemblies. But which type of kit is right for your 4x4?

Types of Diff Drop Kits

Billet Cradle

If you want to use the strongest option you can find you should go for a billet cradle kit. This may also be the most expensive solution but it will offer a completely new set of brackets. These types of diff drop kits are made up of a single lump of steel billet, machined to have the shape of double-ended mounts. This may make the kit heavy but the level of strength it offers will outlast even some of the most essential components of your vehicle.

Welded Cradle/ Arm

The more cost-effective solution than billet cradle kits is a welded cradle kit. The latter has almost the same level of strength at the fraction of the former's weight as well as its price tag. The main benefit of these differential drop kits is that they provide a full 30 mm drop. One of the main drawbacks of welded cradle kits is that they won't last as long as billet cradle kits. Keep in mind that welded cradle kits are not one whole piece, instead, they are multiple pieces welded together, hence their name and lack of longevity.

Puck/ Spacer

When you want to get the simplest solution, which is often the best solution, you should go with a spacer/ puck kit. Usually, these kits have a set of solid steel spacers, known as pucks, which are used on the front differential mounts and the differential cross member. The level of separation pucks/ spacers offer is what allows the height at which the CV joint sits, to drop sometimes even by as little as 9.5 mm. When small drops are needed, a spacer/ puck kit is the best solution.

How to Install a Diff Drop Kit

1. Depending on the type of kit you go for, the installation process will vary but when it comes to making the simplest diff drop, even a beginner can do it. Just take your time and pay close attention to what needs to be done.

2. To start, you should take off the skid plate of your 4x4. This plate is found at the front of your vehicle. When the skid plate is removed you should keep the OEM bolts and then provide support for the differential. This is done with a floor jack.

3. Next, you need to remove the factory bolts as well as nuts that support the front differential and save the OEM washers for later. Then, start lowering the differential. You should go low enough so there is space for the drop spacers to fit. This space will depend on the size of the drop spacers.

4. When the spacers are in, install them between the two front differential supports as well as the front cross-member. Make sure to fasten the spacers to the cross-member using the bolts and nuts provided in the kit and reuse the factory washers you removed earlier on.

5. Follow manufacturer specifications on how to tighten the fasteners you just used to mount the spacers. If you can't find manufacturer-specific specs then usually anywhere between 108 and 122 Nm is going to be enough force.

6. When that's done don't forget to install the front skid plate with its OEM bolts on the front end and the longer bolts with the washers in the kit on the rear. The rear should also have skid spacers placed.

7. When installing the rear skid plate you should use the supplied longer bolts and skid spacers in between the skid plate and frame. This will prevent the skid plate from getting in contact with the differential mounting brackets.

8. In certain instances you may need to trim the skid plate but this will depend entirely on the model of your vehicle. Lastly, all skid plate bolts should be torqued to factory specs. Again, if you don't have that information or can't find it on the internet, then you should be good by torquing them at 33 Nm.

Conclusion

Doing modifications on vehicles as heavy and as big as 4x4s takes some courage but what it also takes is careful planning. When you make a mistake you have to correct it properly and the same goes when you install a lift kit that hurts the CV joints. With the proper diff drop kit, you won't have to worry about any sacrificial damage.