Tips on Buying Differential Seals
The differential seal protects the gears in the differential from harmful contaminants and keeps gear oil from leaking out. So when any of the differential seals in your car's axles break down, they should be replaced with new ones as soon as possible. Replacement differential seals are not that hard to find in the market. Here, we're going to show you some of the kinds of differential seals available for purchase today.
It's more than rubber
The main ? if not sole ? material differential seals are made of is rubber, but this does not mean that all differential seals are made of the same rubber material. In fact, differential seals are made of various types of synthetic rubber, with each one having its own strengths and weaknesses. Some of these common rubber types include:
- Nitrile rubber: The most common type of rubber used in oil seals, nitrile rubber is highly resistant to oil and abrasion. However, it does not provide adequate protection from solvents and extreme temperatures.
- Silicone rubber: It is highly resistant to heat and cold but is not as resistant to water and alkalis compared to other types of rubber.
- Acrylic rubber: It has has the high oil resistance of acrylic rubber and the heat resistance of silicone rubber. However, it is not as good when it comes to water and acids.
- Flourocarbon rubber: Made from organic compounds, this type of rubber is highly resistant to heat, oil, and chemicals. However, it does not fare well under cold weather conditions.
Aside from rubber, differential seals have also been made of the following materials:
- Fabric: It is heat resistant, and it does not fray.
- PTFE: It is composed of synthetic polymer resin that provides excellent resistance against high temperatures, chemicals, and abrasion. It is not, however, as elastic as rubber.
Aftermarket performance seals
In addition to original equipment manufacturer (OEM) seals, there are also the so-called aftermarket performance differential seals. These seals do not follow the same requirements specified by the car manufacturer (like OEM seals do). Instead, they are best for performance applications. Some performance seals, for example, have a special flanged design to prevent against cocking, while others come with a latex bore coat as protection against minor bore imperfections. However, because they do not match the exact specs as OEM seals, not all aftermarket performance seals are not guaranteed to work or last the same as the factory seal. Some aftermarket performance seals tend to be expensive. They are bundled in a kit along with differential bearings and other related components.
How to Change the Differential Seal in Your Car
The differential seals in the front and rear axles of your car serve a dual purpose: to keep the oil in the differential and to keep dirt and other contaminants out. So when any of these seals breaks, you'll have to deal with two problems at the same time. Thankfully, most cars are designed with differential seals to be replaced without having to remove or disassemble the axle. In this repair guide, we are going to show you how to replace the front and rear differential seals in the 2005 3.5 Chevy Colorado.
Difficulty level: Moderate to Difficult
- Flat-head screwdriver
- Needle-nose pliers
- Breaker bar and ratchet
- Combination or box end wrench
- Allen wrench
- Torque wrench
- Jack and jack stands
- Drain pan
Step 1: Loosen the wheel nuts and jack up the side where the seals are going to be replaced. Once the jack is up, place a jack stand under the rear of the lower control arm.
Step 2: Take out the wheel nuts and remove the wheel from the axle. The Colorado also has an inner splash shield around the wheel, so we also had to get it out of the way. If your car has a heat shield and the ABS harness connector, remove them as well.
Step 3: Locate the two bolts that hold the bracket and brake caliper onto the steering knuckle. Take them out and set them aside. Warning: Secure the caliper assembly with a zip tie. Make sure that the caliper isn't hanging by the hose.
Step 4: Find the nut at the upper ball joint's bottom and remove it. Next, use the Allen wrench to keep the stud from turning. Once the nut is removed, rap the knuckle around the upper ball joint with a hammer until it becomes loose.
Step 5: Raise the upper control arm, detach the ball joint stud from the knuckle, and remove the nut that holds the tie rod end to the knuckle.
Step 6: Using the hammer, rap the tie rod stud and knuckle until they come loose. Pull the knuckle just enough so that you can remove the tie rod end.
Step 7: Slide a pry bar or large flat screwdriver between the inner joint and the differential bracket to release the half-shaft from the differential. After that, you have to pry the shaft loose.
Step 8: Unscrew the nuts from the four bolts that secure the bottom ball joint to the lower control arm.
Step 9: While supporting the half-shaft assembly, remove the four lower ball joints. Be careful when pulling out the assembly from your vehicle and placing it on a block of wood.
Step 10: Put a lint-free rag in the seal. Using an old toothbrush and a brake cleaner, keep the area clean around the seal.
Step 11: Use a screwdriver to work the differential seal loose. You can also use a slide hammer to push the seal free.
Step 12: Take the new seal and apply silicone grease on its outer edge. Next, use a socket that's slightly smaller than the seal's outer diameter to hammer the seal into place.
Step 13: When installing the new seal, make sure it's flush with the differential's bore. See to it that the seal's front edge is 1/16"-3/32" past the bracket.
Step 14: Using a brake cleaner and brush, clean the inner CV joint and shaft end. Once these are free from dirt, put some 75W-90 lubricant onto the shaft and the new seal's lip.
Step 15: Reinstall the half-shaft assembly and the other components you have removed beforehand. Make sure to retighten all the bolts by hand to their proper torque.
Step 16: Remove the jack and reinstall the wheel. After taking out the fill plug from the differential cover, you have to apply synthetic 75W-90 gear lube. Make sure this reaches the hole's bottom.
Step 17: After lowering the vehicle and removing it on jack stands, take it for a spin to check if everything's properly installed.