The differential is a multi-tasker, but its main purpose is, putting it simply, to make the wheels spin. The thing is, there is only one engine in the car, but there is more than one wheel. And that’s why we need the differential. Four-wheel-drive cars mostly come equipped with not one but two differentials – front and rear.
Over time, this gear breaks down, and differential leaks are a problem that most drivers come across at some point. Yes, this is quite a common issue, so don’t worry if you’re experiencing it right now. There are a few reasons differentials start to leak. In today’s guide, we’ll tell you what causes the leaks and how to make the rear differential stop leak.
Six Most Common Causes of a Differential Leak
#1 Damaged or worn differential gasket
At some point, differential gaskets will wear out or get damaged, causing leaks in the differential. Unfortunately, when this happens, there is no other choice but to replace the old gasket with a new one. It won’t cost much, though.
#2 There is an issue with a differential rear pinion seal
A pinion seal is located at the back of the differential. It’s there to seal the area where the driveshaft enters the differential. Eventually, the seal will become worn or damaged, just like the gasket. And just like with the gasket, the only thing you can do is replace the old pinion seal with a new one from a local store. Do that as soon as possible.
#3 Damaged Differential Cover
There are two reasons why differential covers get damaged: it’s either corrosion or physical impact (say, a rock hitting it while you’re on the road). Anyway, a damaged or cracked cover will lead to leaks. Well, you need to get it fixed, and you should do it sooner rather than later. Otherwise, you may end up replacing the whole thing, which will cost considerably more.
#4 There is an issue with differential side seals
Similar to the rear pinion seal, the side seals are there to seal the bearings. And just like the rear seal, these seals may also wear out or get damaged over time. So, the question is – can you repair them? No, not really: the only thing you can do about it is have the old, faulty seals removed and replaced with new ones. Do this the moment you find out that the differential is leaking to prevent bigger leaks and further damage.
#5 Leaks in differential tubes
Over time, differential tubes may become damaged or worn out. If this happens, there will be leaks in your differential. Repairs aren’t an option here, either. On the bright side, replacing the tubes won’t leave your wallet empty.
#6 Worn Axle Seal
You can find the axle seal at the end of the axle, right where the axle and the differential meet. Just like all the other seals in the differential, the axle seal is also prone to wear, tear, and damage. Installing a brand-new axle seal won’t be cheap, but it’s a necessary investment into your own safety.
Some useful tips that will prevent your differential from leaking:
- Regularly check the fluid level and use high-quality oil
- Despite the price increases, even top-shelf oil like the best oil for 4.3 Vortec is still affordable
- Take your car to a repair shop now and then even when the vehicle works just fine
- Keep the area around the differential clean.