Oil Seals

Fig. 2:

Fig. 3:

Always fit new oil seals when rebuilding an assembly. Examine the seal before fitting to ensure that it is clean and undamaged. Smear sealing lips with clean grease, pack dust excluder seals with grease and pack grease into the cavity between the sealing lips of duplex seals. Ensure that the seal spring, if provided, is correctly fitted.

Place the lip of the seal towards the fluid to be sealed and slide it into position on the shaft, using a fitting sleeve (Fig. 2) when possible to protect the sealing lip from damage by threads, splines or sharp edges on the end of the shaft. If a fitting sleeve is not available, use plastic tube or adhesive tape to prevent damage to the sealing lip.

Grease the outside diameter of the seal, place it square to the housing recess and press it into position, using great care and, where available, a seal installer (Fig. 3) to ensure that the seal does not tilt. In some cases it may be preferable to fit the seal to the housing before fitting it to the shaft. Never let the weight of an unsupported shaft rest in a seal. If the correct service tool is not available, use a piece of tube which is approximately 0,4 mm (0.015 in) smaller than the outside diameter of the seal. Use a press to install the seal or use a hammer VERY GENTLY on the tubular drift if a press is unsuitable or not available.

Press or drift the seal in to the full depth of the housing if the housing is shouldered, or flush with the face of the housing where no shoulder is provided.


NOTE: Careless fitting of oil seals, which can result in damage to the seal and sealing surfaces, accounts for most cases of failure of seals. Care in fitting is essential if good results are to be obtained.