2 years ago I replaced my rear diff pinion seal (and one other seal that my mechanic swapped out while they were working on the diff). At the time my car had 105k km on it. Now at 139k km I have another pinion seal leak. Pretty disappointing. I'm going to have it replaced in the next week or so but I'm wondering if there's anything that can be done to ensure the seal lasts longer. I guess the excess carborundum/manufacturing defect is prematurely wearing the seal. Perhaps a full flush of the diff could sort the issue? Any advice would be greatly appreciated. Thanks.

 

Well from my experience seals going bad prematurely is usually due to a bad install. Seals don't like to be installed wrong as in crooked, dry against what they seal, on a dirty surface, excessive run out of the part they seal will make them fail fast too, as does high heat. I wouldn't flush the diff out either, the gears and bearings rely on a film of gear lube that coats even when not in operation to protect and lubricate, flushing would just wash that film away. And some times it's not the rubber seal thats leaking, I've seen seals leak from around the hole they are mounted in (especially pinion seals) which is why I slather sealant around the outside of any seal I install. As far as leak prevention, just make sure it's installed right and not dry.

 

Thanks for the reply Will. From doing research over the past few days it looks like there was also a design flaw in the old batch of diffs (hence the reason that Jaguar discontinued stocking those diffs and now stock a heavier duty replacement). From what I read the pinion in the original diffs wasn't manufactured to correct specifications and was causing considerable wear on the seal over time. Once my pinion seal is replaced I think I'll look at more long term solutions (like a quaife diff) in the future.

Given the fact that my diff is leaking a ton now that the fluid was topped up it leads me to believe that the pinion seal that was replaced a couple years ago failed in relatively short order and I just didn't notice the gear oil leakage. I suppose that I've been lucky to catch these leaks before they've caused a catastrophic diff failure all together.