How to change rear Differential Fluid (detailed version)

How to change rear Differential Fluid (detailed version)

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 The likes help me out, and if you subscribe you get feet update when I upload a new video

About the Author: Michael Flood


  1. thanks cris most helpful for us even i dont have car but mechanic life it is more knowledge to quick work everyday thanks cris…..additional idea..

  2. I am not saying that he is wrong about letting the seal pack dry before you go and stick it on there, however I will say that everything that Toyota, Honda, and Subaru says about using seal pack/RTV gasket maker is to stick it on and have everything tightened and final torqued within 5 minutes of application.

  3. I'm new to your channel but it's been a lot of help…. I just bought a 2000 V6 3.8 later Mustang for my son it's going to be an awesome project

  4. Thanks so much for this video. I was able to do this on my 83 Chevy with this video as my only resource. Thanks Chris

  5. Most rear differentials have a drain plug at the bottom of the housing aswell so you dont have to pull the cover. It takes a 3/8 drive ratchet too. Much easier, 10 min job.

  6. I have a 2010 Ford ranger and I never changed the differential fluid it has 46,000 miles and with this video was very helpful… Thank you keep doing your videos

  7. Question for you Chris or anyone else that has a suggestion (s) or directive… concerning rear E150 Econoline Def. ( 5.4L ) 1998. I noticed you drained and inspected and refilled… But you did not clean the inner cavity at all. Might it have been a good idea to do a service ( cleaning ) of the cavity… to remove as much of the old Def fluid and any possible debris, regardless of it being old spent def fluid or metal particles etc…. And if you did clean it, how might you have done so… what product (s) might you have used and would you use a particular technique? Thanks… Great def service video..

  8. If in an emergency, you can replace the axle oil with papaya fruit.
    Although the spare parts inside broke, if you use papaya everything feels smooth without any noise.
    It's just not able to last long, because this is used in an emergency.

  9. вопрос-а что в этом мосту сливной пробки нет?масло не меняется а только доливается?зачем через крышку то сливать?

  10. my dads differential had a little chip and my dad says everything will be alright and 3 minutes later i see theres a leak my dad is like damn sorry son even i told him it will leak

  11. That's soo clever leaving one bolt in the top. Who would of thought of such a thing. Like loosen lug nuts before jacking up the car. WoW…everyone would be soo screwed if it wasn't for Chris Fix. Soooo…that rusted out rear shock is just fine…right?

  12. Never thought I'd use this info when I first watched this video a few years ago. but here I am, underneath a chevy 1500, making sure I'm doing this right

  13. I'm still left wondering why we don't rinse out the main housing with brake clean after the fluid is drained. Getting ready to do this job and can't find an answer to that question.

  14. I changed my fluid before and gently pried the cover as little as possible just to barley drain the fluid and bolted everything back up and it never leaked.

    Just saying

  15. Thanks for this video. Gotta replace my rear pinion seal and differential seal because of a clogged rear axle vent. guess the guy i bought my ranger from launched boats with it and clogged it up so im trying to fix everything that im comfortable with by myself

  16. Using a screwdriver to pry off the cover is not a good idea. The gauge of steel used in a lot of covers is not that thick. They're easy to bend just enough to cause an annoying leak.

  17. As long as you have a gasket, the surface condition, as long as it's clean, is not a huge concern. Metal scrapers won't compromise the seal. Toluene or diesel fuel works wonders to clean it too.

Leave a Reply

Your email address will not be published. Required fields are marked *