Having problems installing oil seals? The part has had many updates in recent years, which has totally changed the installation process. In this blog, our specialists will give you information and installation tips so that these oil seals no longer cause difficulties during your overhaul or repair job.

What are oil seals?

Unthinkable in the list of seals are oil seals, which provide a seal against splashing oil. The most important oil seals are used for rotating shafts and valve stem seals. Oil seals are intentionally never completely sealed to lubricate the seals and prevent wear.

Today, traditional oil seals have to compete with a new variant oil seal, which is used in most modern engines.

Conventional oil seals

Conventional oil seals are the traditional seals, which can be recognised by a spring on the inside. These oil seals are made of a metal housing that contains a rubber seal. This part is often made of elastomer and comes into contact with the surface of the rotating shaft.

PTFE oil seals

Oil seals increasingly had to meet higher requirements, which is why PTFE was developed in 1980. This variant can better withstand higher engine speeds, higher oil temperatures, longer oil intervals and modern lubricants. In addition, the oil seal contains a wider contact surface, which ensures less wear.

PTFE is special in that a pre-tensioned spring is not required. This is because the material returns to its original shape when heated, also known as the shape-memory polymers (SMPs) effect. These oil seals are also supplied as integrated parts, where it only needs to be installed as one component.

Updates in oil seals

Developments and issues

Seals, including oil seals, have undergone a great development in recent years and are totally unlike the original product. PTFE has taken over the oil seals market for modern engines mainly because traditional oil seals started causing more and more problems. Such as evaporation of chemical plasticisers from the elastomeric material, which eventually caused engine oil leakage. Now, the focus is more on durability and frequency of servicing.

However, the new variant also comes with less good properties. Namely less flexibility and less resistance during assembly. Most damages therefore occur during the installation of PTFE oil seals.

Step-by-step plan for correct installation

With the help of tips and information from our suppliers, our specialists will be happy to explain how to install oil seals. Please read the instructions carefully before installation.

1. Only remove PTFE oil seals from their packaging just before installation to protect them from dust and other contamination.
2. The sealing lip of PTFE oil seals is protected by a plastic sleeve, which can normally be used as a mounting aid. Therefore, the sleeve should remain in place until the seal is installed. 
3. We highly recommend to use special tools when installing oil seals without a plastic sleeve. You can find the advice around the right tool from the manufacturer. 
4. Both the PTFE sealing lip and the shaft surface must be completely dry. Do not use grease or oil. If grease or oil is used, the retaining ring will fail after assembly. 
5. The shaft must not have any sharp edges. If necessary, have the edges removed by a specialist.
6. The shaft surface must be in perfect condition. Have any damage repaired by a specialist.
7. Place the mounting sleeve with the PTFE oil seal on the shaft.
8. Pay attention to the correct alignment of the oil seals. The sleeve should lie so that the seal can be slid smoothly onto the shaft.
9. Press the retaining ring onto the shaft with an even movement.
10. When replacing, the PTFE sealing lip of the new oil seal should not be in the same position as the old oil seal. The diameter of the sealing lip should be smaller than the shaft diameter.
11. Remove the mounting sleeve.
12. Do not top up engine oil and do not start the engine until four hours after assembly. This is advised by both Elring and Victor Reinz to allow the new oil seals to form to the shaft. 
13. Note! Seals with housing also require screws to be tightened according to factory guidelines.

If you follow the above instructions, the oil seals should work properly. Also watch the video below for an example of the installation process.

Examples of defects

In addition to the installation procedure, our specialists and suppliers would also like to draw your attention to some cases that occur around oil seals.

Case study 1: Volkswagen

Special exceptions still apply within the Volkswagen group. With PTFE oil seals, an aluminium or plastic housing is used in many different engine series. The Top Dead Centre (TDC) signal is no longer measured at the flywheel, but directly using a sensor on the rear crankshaft flange and integrated sensor in the oil seal. Special procedures and tools must be used for the disassembly and assembly of these parts.

Case study 2: Silicone oil leakage

Oil seal WG1087811 is used by several automotive manufacturers, such as Opel, Fiat and Suzuki, and serves as a good example for an oil seal where oil leakage can occur if fitted incorrectly.

Indeed, when installing this oil seal, the oil sump must be installed using silicone seal. Removal of the old seal and oil sump is necessary, otherwise the oil seal cannot be fitted properly either. If these steps are not followed, leakage is inevitable.

Also, sealant should never be used on the housing and the installation guidelines, as discussed earlier, should be followed.

Click here for installation instructions

Case study 3: Product changes in oil seals

Our suppliers try to provide the best quality oil seals and products are in some cases optimised to improve performance and fitment. Corteco is one of these brands, whose case studies we have listed for you.

• WG1222500, WG1222558, WG1222506
  Update: Leakage-free
  Agricultural vehicles including Iveco, Opel, Massey Ferguson and Fiat
  
• WG1222658, WG1222672, WG1222727
  Update: Leakage-free
  Agricultural vehicles including Mercedes-Benz, Renault and MAN
  
• WG1223546
  Update: Leakage-free
  Passenger cars
  
• WG1219950
  Update: Material
  Trucks including DAF, Iveco and MAN
  
• WG1222898
  Update: Size
  Agricultural vehicles from New Holland and Cagiva, among others
  

Range of Wilmink Engine Parts

Wilmink Engine Parts offers a wide range of oil seals for various applications and engines. Poor-quality oil seals can cause problems. Our range offers only quality brands and our specialists will be happy to help you choose the right product for your application. Below, we highlight some of our brands with their catalogues around oil seals.

Corteco

Corteco is a well-known brand in the automotive industry, supplying top-quality oil seals, including the first Simmerring® in 1929. The range consists of more than 7000 gaskets and more than 6500 OE-quality shaft and valve stem seals.

Click here for Corteco's catalogue

Victor Reinz

For quality gaskets, Victor Reinz is the place to be. The German company invented the head gasket, but today it also specialises in other types of seals, including oil seals.

Click here for the Victor Reinz catalogue

Elring

Elring supplies liquid sealants, head gaskets and also oil seals. The extensive range almost always offers a solution for an engine block and quality is can’t be missed in Elring's product range.

Click here for the Elring catalogue

Do you still have specific questions about oil seals installation or want to know the right type for your application? Then please contact our specialists. They will be happy to help you with information and advice.