Hey guys Chrisfix here. We're going to change the fluid in the rear differential today this right here is the rear differential
What it does is it translates power from the drive Shaft into this rear end to go to each wheel so the first thing?
We're going to do is
Look for the filler plug and make sure we could unscrew [that] because if you can't unscrew your filler plug
Then you'll drain the whole thing and you won't be able to fill it back up with fluid
So let's make sure we could unscrew that this process that I'm about to go through will work for
Almost every rear differential vehicle this happens to be an open diff. It doesn't have limited slip differential
So you can figure that out with the tag here. It'll tell you on the tag if it's a limited slip or not
So if it's limited slip you would have to add limited slip additive, but that's the only difference in what I'm doing right now
I don't have to do that because I just have a regular open diff in order to do this job properly here are the tools?
You're [going] to need so you're going to need a ratchet
you're going to need an extension, and you're [gonna] need a half an inch socket, and that'll take the diff cover on and off and
Also, the fill valve on and off you're going to need a screwdriver a flathead screwdriver to pry the dip cover off you're going to
need a gasket or RTV
to make a gasket, and then I use the pliers to cut the tip of the RTV you're going to need a
Plastic don't use a metal one you're going to need a plastic scraper to scrape the old gasket off break clean to clean
the mating surfaces some paper towels and oil catch can to catch all the drained oil
torque Wrench to properly torque up your bolts when you put the cover back on and some gear oil to fill up the
Differential when you're done if you have a limited slip differential you're also going to need limited slip additive
And then you're going to need a pump to pump up the fluid from the can into your differential
And that's all you're going to need let's get started different vehicles
Have the filler plug in different locations [on] my mazda P3000 Ford Ranger. I have the filler plug
Right back here. I'll show you in a second
You can see it right there
All you need is the box end of a ratchet. I'm going to use an extension
So it could fit in here better because it's kind of tight, and you might want to use a breaker bar
[I] don't think I'm going to have to but if you have trouble getting this off you could use a breaker bar and let's uh
Let's unscrew this make sure it comes off
So we're [just] going to use the [box] end
of an extension here
So the back of the drain plug is actually magnetic and you can see all
The little Shards of metal and stuff which is okay. [I] want to make sure you clean that off
so the next thing I want to do is you want to check your fluid level so just stick your finger in and
I could feel the fluid right right up to the edge where it's supposed to be so the fluids up high enough good
So to prevent contamination. I'm just going to screw this back in
That'll be good because we're going to just change the fluid out now. Now we will put the oil Catch-can
Underneath and start unbolting these [we'll] start from the top and go [down] and we'll leave this Middle one for the last
This is a half inch ratchet
So now we have this last one up here. We're going to unscrew about halfway
Just so when we pop this off the whole thing doesn't come off
We just want the bottom to [open] up to let the fluid drain out
So we're going to leave it about right there, and now we're getting a screwdriver and pry this off so get your screwdriver
Get it in between the case
like so
And let it drain
Now you can see leaving this on top
Prevents this case from falling off which would just make even bigger mess
So now I'm going to finish unscrewing the top because it's pretty much done leaking out
And I'm going to take my cover off and let the rest leak out
So here's my differential cover, and now what you want to do is you want to clean this up really good?
So you're going to get all the gasket off and clean out all the [oil] in here and to help you
You could use some brake cleaner
So with most of it clean I'm going to just spray some brake cleaner on there
The most important part is to get this surface right [here] where it's going to made up with differential as clean and smooth as possible
[you] can see that
There's no cuts or divots or grooves or anything in this because if there is then you'll get a leak
So this is nice and smooth. We're just going to clean it up some more
So now with this surface nice and clean I also clean the inside
On yours there might be a magnet in here
you want [to] make sure you clean the magnet off and
Now we're going to go and clean the surface on the differential
So here is the differential and you want to make sure the mating surface here is cleaned off
so I'm just going to take a paper towel and
[wipe] it off there might be some hard parts like up here that you need to pull off of
like the old Gasket
You don't want to use a screwdriver or anything that could scrape the surface once you put a scratch in here?
It's going to leak so you want to try to use any tools that that won't scrape it
I'm going to get a plastic scraper plastic won't scratch the metal and I'm just going to make sure this is nice and flat
Okay after [scraping] it down and wiping it down just inspect to make sure it's nice and smooth
That feels really good now. We're going to clean this surface with brake cleaner
But we're not going to spray it on we're gonna spray it on a paper towel first and then wipe this down
So now I have a paper towel with brake clean on it, and I'm just going to go around
and clean off the mating surface
So the towel [is] really dirty. I'm going to do this one more time with [a] nice clean towel
Good nice
and clean nice and smooth now if you have a gasket you would put the gasket on and then screw the cover on and
tighten it up and
Go in a star pattern while you're tightening
But this differential is hard to find a gasket for it
So I'm going to make my own gasket with RTV and I'm going to show you how to do that right now
So now we're just going to go over one more time with a paper towel
Make sure the surface is clean and now we're going to use our RTV
This is a high temp version you don't need the high tech version. It's all they had
But it's pretty much
It's a silicone gasket maker and you want to make sure it's good for rear differentials because some rear differential fluid will
Disintegrate the silicone this one works for differentials, so just take the cap
puncture the top of the RTV like so
Now you're going to cut this to the desired thickness, so I'm going to try this thickness first you could always cut it thicker
But you can't go back
Just screw that on
Now we want to try to make a continuous bead going around the inside of these bolt holes
so you're going to want to start the bead at the top of the differential because that's going to be the weakest spot of the
Bead and that's right here
And that's about a quarter of an inch thickness right in the middle of the surface
Take your time
Your goals for one continuous bead
It's not the end of the world if you can't get a continuous, it'll smooth itself
Like so you only need to do this if you don't have a gasket and now you're going to just let it sit for about
15 minutes let it get a little bit tacky and then we're going to put it on the differential
But we're not going to tighten it all the way within
15 minutes to an hour you want to get this on your rear differential and
Tighten it down just hand tighten it. So that the gasket gets compressed and any air bubbles get pushed out
And it makes a nice seal with your other mating surface
So I'm going to go show you that now
Now would be a good time to go in and check your gears make sure there's no cracks. There's no chips
There's nowhere that you could visually see um
[I] just did that mine looks good now. I'm going to put the rear differential cover back on with the RTV
So the key thing here is going to be get these two bolts in top and bottom without moving it around too much
So I'm going to push the bolt through the top
and I'm going to push the bolt through the bottom and I'm going to do my best to
align this without
smearing
Good top and bottom bolts are in I'm going to hand tighten the bottom one first
and tighten the top one not all the way but
[just] enough so that you start feeling a little bit of resistance
And now we're going to go in a star pattern I'm going to start from the bottom
Go top
bottom top side side side side
Now you could either torque them to about 5
foot pounds each in that star pattern or just tighten them [down] [until] you see [a] little bit of the red RTV coming out and
Then leave it don't tighten it all the way
So you can see the RTV is
Starting to come out and I'm literally just lightly
Turning it using only the head of this, so there's no torque
And I'm just making sure this is just tightened lightly by hand so once the RTV starts to come out like that
You've done your job. It's like that around the whole thing
so you're just going to let it sit for an hour and
Then you're going to torque it down to specs and the torque specs for this are 25 to 35 foot pounds
so let's wait an hour, and then we'll go torque them [down] an hour later set your torque wrench to ten foot pounds and
We'll start tightening these down start with the center one
remember going a star pattern [if] you want to see how to use a torque wrench just click the video on the
[screen] or check the description I have [a] good video to show you the basics. It's really quick. [I] think it's like [2] minutes
So after you go around once at 10 now
You're going to switch it to whatever your torque spec is so my [taurus] [pecks] 25 foot-pounds
Now we're going to talk it down
25 Foot-Pounds Star Pattern
Good, they're all torqued down now. We're going to go to the fill plug on the other side
And that's the angle you're going to see next so we're back at the fill plug. I'm going to take it out
Now I have my gear oil
right down here
Ready to go and my pump and we're going to fill it up until it starts [leaking] out of here put your pump
hose in
And put the other [end] in your gear oil. I'm using a tw 90 Gl-5 and
Now you just start pumping
So once it starts leaking out like that. Just get your finger in there
You see it's all the way filled up, and now we'll screw the fill plug back in 15 pound-feet of torque
Tighten it down to 15 pound feet of torque, and then you're done
That's how you change the rear differential fluid you can see there's going to be videos popping up here here
I'll put the how to change a transfer case fluid and I'll have a few more videos here if you click on them
They'll lead you to other how-to videos that are very helpful save you money if this video was helpful click like and subscribe
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