Front and rear crank oil seal replacement
 All of these tools are available for hire too                                                      2  videos at bottom of the page

                          Front and rear crankshaft oil seal removal and insertion           

There are 3 sizes of rear oil seal inserters. Front oil seals are the same size on ALL 2cv engines, the rear ones are all different sizes The rear tools all differ in size to accomodate different crankshaft sizes for the flywheel attachment tool and enable the oil seal to be inserted correctly to the correct depth They all consist of 3, 8mm x1mm cap head screws, an adapter with a slight taper, which fastens to the crankshaft with the screws, it is centralised with an addition hole for the crank/flywheel dowel and is 0.1mm oversize of the crankshaft, the oil seal pusher, the cup mandrel and a long 10mm x 1.25mm bolt and nut.

Look at the hole that the seal will fit into. You will see a taper at the beginning of the hole. The seal, when in its proper position, will be up to the end of this taper. The shape of the tool faces ensures that this is where the seal will be positioned. Oil or grease the hole and the seal.

 Fasten the adapter to the crankshaft,  tighten the screws slightly, they do not need to be too tight, it is now centralised on the crankshaft. Oil the adapter and seal and slip the oil seal onto it and push it up the taper until it is flush with the entrance hole. Slip on the pusher up to the seal, WITH THE LARGER DIAMETER TOWARDS THE SEAL.  Next, offer up the cup and long bolt. Screw in the bolt until it bottoms, whilst keeping the cup central to the pusher. Everything is now in line and centralised to the crankshaft. Screw the nut down to insert the seal until it is just tight. The seal is inserted correctly and to the correct depth and will be leak proof and should be at the bottom of the taper on the entrance to the hole in the crankcase. The engines for the 3 sizes of inserter are as follows. 425/435, M4, 602.

Front oil seal insertion.


All 2cv engines have the same size of front crankshaft oil seal, so, one tool will do all of these seal insertions.

The tool consists of a pusher tube, long 10mm x 1.25mm bolt and a nut. The seal has to go to the correct depth and the pusher is machined to accomodate this.


Oil the seal and the entrance hole and slip the seal up to the hole and adjust it squarely. Fasten the tube to the crankshaft until the bolt bottoms and adjust it to the seal and finger tighten the nut. Screw down the nut until it is just tight. The seal is inserted correctly and to the correct depth and will be leak proof. It will be flush with the crankcase bore.


                                            complete tool                                                                                                              adapter
                                                                                                                                 the hole in the middle is the same size as the spigot bush housing,
                                                                                                                                             therefore the tool must be central to the crankshaft

                 The taper is visible                                                                             The centre of the adapter is an exact fit onto the crankshaft spigot bush
                                                                                                                               housing and centres the tool to prevent any damage to the seal.
                                                                                                                               Note the taper. This matches the inside taper on the seal entrance hole

                                   cup pusher

                                                           seal pusher
                                                    The rear oil seal inserter tools


              The depth inside the tool is machined accurately to ensure correct seating of the seal

The depth in the tool is critical to insert the seal to its correct position. When installed the seal will be flush with the crankcase.

extraction tool ----- hook and slide hammer

               insert the tool about 8mm, with the flat side next to the crankshaft, NOT, the round side

  Turn the tool slightly until contact is felt. The hook will be behind the metal part of the seal
     Gently slide hammer, the seal will slowly come out. Do not over hit the tool, as you could
                                             damage or break the tip as it is quite thin.


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