Pinion seals, (like everything else in our world), leak.
We change a lot of them. And while the $2.49 seal this is often a great solution (click here if you need one), we all need to be very aware that there is often more to the story. The seal is only part of the battle. What rides on the seal is often the issue.
In the photo above, the differential flange that mates with the back of the driveshaft is horribly rusty and pitted. Thus the surface that mates with the new pinion seal is abrasive, and just waiting for a chance to eat the new seal for lunch. You can see the dark groove where the metal part has digested the rubber lip seal, which left no seal at all.
In this case, we needed a new (used) differential flange with a clean surface to mate to the rubber seal. This new metal part, with a new rubber seal, fixes the leak.
Unfortunately, the metal differential flanges are not available (we were lucky to have one), so it is important to first try to clean up yours should you have a leak at this location. If you can’t, your next best option is a speedi sleeve, which we sell and you can see by clicking here. The sleeve makes a new mating surface for the seal, and, with a new seal, will fix the leak.
Some people presume that a new seal is the answer. Make sure you consider the two sides to every story, otherwise you run the risk of changing the seal and returning a second time to fix it right.