We replace the half-shaft oil seal (pinion seal) if an oil leak appears from under the flange.
Before replacing the seal, it is imperative to ensure that the rear axle breather is not blocked. If pressure builds up in the housing due to a blocked breather, even a new seal may fail to retain the oil.
We position the vehicle on a lift or in an inspection pit.
We disconnect the propeller shaft (see article – Construction and repair of the propeller shaft). Note: it is sufficient to unscrew the bolts securing the propeller shaft flange to the pinion flange and swing the rear part of the propeller shaft to the side, without removing it completely.
We remove the split pin from the drive pinion flange nut.
Using a 24 mm socket, we unscrew the nut, holding the pinion flange with a pipe wrench to prevent it from turning.
We remove the lock washer by carefully prying it up with a screwdriver.
With light taps of a hammer (preferably through a wooden or brass spacer), we remove the drive pinion flange.
Using a screwdriver, we carefully pry out and remove the old oil seal.
After generously lubricating the lips of the new oil seal with plastic grease (e.g., Litol-24), we press it in, using the old oil seal as a pressing tool.
Important: The catalogue number for the applicable oil seal is: 24-10-2402052. The seal must not be pressed in too deeply. Its outer edge must be strictly flush with the edge of the hole in the axle housing.
We install all parts in reverse order.
We tighten the pinion flange nut with a torque wrench to a torque of 160–200 N·m (16–20 kgf·m) until the slot aligns with the split pin hole. Note: after replacing the seal, it is recommended to check and, if necessary, adjust the preload of the drive pinion bearings.