what does a leak in the rear differential mean?

Question

I have just been told that the rear differential is leaking in my rear-wheel drive car - what does this mean?

Answer 1

A leak in the rear diff. means that the fluids are leaking due to damage to the differential. If all the fluids, which keep the differential lubricated, run out, you will have a differential break-down which will cost a lot to fix.
P.S. I LOVED IT WHEN YOU SAID "IN MY RWD CAR" I LOVE IT WHEN WOMEN TALK ABOUT CARS.

Answer 2

99% of the time it means the seal around the removable pan is leaking either from running over something and scraping the differential housing or old age and the paper gasket is shot.

If you have a differential that is mounted to the body and the axles come out of it to the wheels, like a Jaguar, the axle seals may be leaking where the axles enter the differential housing.

If it has a conventional rear end and you had a brake inspection and there's gear oil on the brake shoes, this means the axle seals are letting gear oil to leak past. 99.999% of the time the reason for this particular leak is wear and tear of the wheel bearings which sit just inside the axle seals. Since they have to pull the rear end apart anyway to change these seals they should always replace the bearings along with the seals.

A pinion gear seal rarely if ever leaks. This is the least likely casue of the leak. Again, if this seal ever leaks it's due to wear and tear on the pinion bearing. This seal should only be changed by a shop that handles rear end rebuilds exclusively since this is a crush style seal/washer and the gear lash beween the ring and pinion gear has to be re-gauged with a feeler gauge. They'd gauge the whole diffential as well and replace any worn gears. There's the proper way and then there's the Goober way.

Hope this helps.

Good Luck!

Answer 3

If your leak is in the center or the car it's either the cover gasket, which you could fix yourself, or the pinion seal. The pinion seal is something you'd probably have to have done in a shop but it's not too expensive. If the leak is on the outboard end by the tire it's an axle seal, also something you should probably have done in a shop. More serious would be a brake fluid leak. Make sure the fluid leaking is brown and not clear. If it's clear get it to a shop pronto. You have a dual braking system but take it easy anyway as your rear brakes would not be functional. An axle leak you can live with, brakes you probably can't.

Answer 4

Kind of like automotive diarea followed by a broken leg. Seriously, probably just a leaking seal, but it can drain the oil out of the differential, allow dirt in and over time cause major damage to the gears. Easy fix at home.

Answer 5

Could be gasket bad and leaking or if it is a Pinion Seal then OUCH!! Is it a Differential Cover or Pionion seal....? What type of auto>?

Answer 6

this means you better fix it. if you are mechanically inclined. get under the car wipe every thing off all grease oil whatever and see where it is coming from. it could be the bolts are not tight or you may have the plug lose. wipe it look at it then you will know what and where it is leaking. take it to a shop and make sure you have enough oil in there or you will ruin the rearend. maybe you need to replace the gasket. i sure would like to see it.

Answer 7

Who ever told you,ask what kind of leak? Is it the inspection cover or the pinion seal???

Answer 8

pinion seal at the drive flange,or the axel seals they will glaze yer brakes if a drum system