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Oil Spots Under the Rear of My Car Truck Diagnose Differential Leaks

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Created on: 2020-02-10

This video shows you how to figure out if a rear differential leak is happening on your vehicle, and what to do about it.

Hey, friends. It's Len here from 1A Auto. I made my way underneath the rear-wheel-drive vehicle because I wanna show you something simple as checking for a rear differential leak. We have several on this vehicle, so let's take a look. So, let's start right in the center of the differential. This area right here is called the pumpkin of the differential. And if you look up along the front area of it where it connects to the driveshaft, you're gonna see an area called the pinion seal. If you have a leak right up here, it's gonna work its way down the differential and make a mess. A lot of this mess is more than likely from this pinion seal.

To fix this seal right here, what you would need to start off by doing is to remove your driveshaft. You take out these four bolts, bonk this a couple of times. If you take a look up here, your exhaust may or may not be in the way. If it is, you're gonna have to drop the exhaust. If it isn't, hopefully, it'll just be able to come down. Once that's out, right behind this area right here, you're gonna see a big old nut. You're gonna remove that nut. Take a rubber mallet, bonk, bonk, bonk.

Right behind there, you're gonna see the seal. We'll pull that seal out, clean the area very thoroughly, put in our new seal, put that back in, put that on, put your driveshaft back up in, mount this back up, and torque this to manufacturer specifications. Make sure your fluid's full inside your differential and your transmission, if anything came out. Then take it for a road test. So, we'll come along to the backside of the differential, and this is the cover area. Of course, if there's a cover and it's a separate part from the differential, you're gonna have a seal.

If that seal's leaking, you're gonna see it coming down along this area right here, and it'll accumulate down along the bottom. What you're gonna wanna do is grab a bucket, take out all these bolts right here, drop the cover down, remove that gasket, clean up the pan, clean up the differential, put in a new gasket, cover back on, all those bolts, torque them up great, and then make sure you fill the differential. Take it for a road test. Have some fun.

Following the differential tube this way, you might see a leak down along this area, and that would be a differential tube leak. If you had moisture right along here, more than likely, it's from rot. Sometimes vehicles will have a sticker going along their differential tube, and that'll accumulate moisture. You'll see build-up of rot. As you pick that away, you're gonna see more and more moisture, and it'll be actually fluid seeping down through the differential tube. If you have that, you've got big problems and you're more than likely gonna need a differential or a major overhaul on your rear differential.

Right up along the top area of your differential, generally on the tube or on the pumpkin, you're gonna see something that looks a little bit like this. It can differ. But this is a vent, and that just vents the air inside the pumpkin. You wanna make sure that that's not missing and it's definitely not clogged up. That'll cause issues down the line. So, we'll continue on over to the end. And this is the very end of your differential tube. There's gonna be an axle seal that's located right on the inside portion here. If you see moisture coming along this area right there, more than likely, that's because you have an axle seal leak. This is pretty much what it would look like if it didn't have a leak.

So, if you have an axle seal leak, the first thing you're gonna wanna do is remove the wheel and the brakes so you can see the axle clearly. Once you can see the axle, you're gonna follow it along over to here, and you have your differential cover. Drop the cover, remove the bolt that's inside there that's holding the axle in, pull out the axle, clean the area, remove the seal, put your new seal in, axle, fill it up, down the road you go.

Having said all that, I hope I gave you a better idea of different places you can look for, for leaks on your rear differential.

Thanks for watching. Visit 1aauto.com for quality auto parts shipped to your door, the place for DIY auto repair. And if you enjoyed this video, please click the subscribe button.

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