Fair warning upfront that this one has quite a few more pictures than the other posts I’ve done. I have to stay ahead of bdhunter’s thread and I also have to pass ncjeeper’s older thread so… here we go!
Today I changed the fluid in my rear differential. It looked like an easy thing to do, I’m sure mine had never been done, and I wanted to paint my cover so I figured why not? I have also been wanting to check my spare to see if it will actually hold up. It’s the original spare that came with the truck… and still has the nubby things… and the original dealer PSI sticker (proof below). The rear differential is easier to get to with the spare out of the way so I figured this would be a good time to do this.
Just a note, different differentials take different types of oil. Make sure you get the right one for yours.
First things first, here’s what we’re looking at. The rear differential is the circular/hexagonal section in between the two axles. For those of you that don’t know (like me before I learned about this) this is the housing for your drive shaft that spins the tires. Without this you don’t go anywhere. As you can see the spare is in the way, so let’s get it down!
Now the spare is out and we have a lot more room to work with:
Here’s a close up of the rear cover:
When I read how to do this originally the guy said he didn’t jack the truck up. He must have been a twig because I could barely get around under there. Those jack stands I bought were great and really made the job a lot nicer:
Now that we’re set up it’s time to get started. There is a drain plug on the front driver side of the rear diff. Remove that and there will be some gear oil that drains out. Make sure whatever you’re using to catch the fluid is in place:
Once you have the plug out set it aside. Time to work on the cover. Go ahead and remove all of the bolts except the top center one. Loosen that bolt but don’t remove it. Then take a flat head screw driver and a hammer and gently tap the screwdriver. There is a seal around the cover that you need to break. Once to get through just wiggle the screwdriver around and out comes the fluid.
And now we can remove the last bolt and get the cover off:
And here are the guts of the differential. Let this sit for a while as the rest of the oil will slowly drain out:
Now it’s time to clean the cover up really well so I can paint it. The inside is coated with oil. Some paper towels will get a lot of the initial junk out, then I used some brake cleaner and rags to get the rest out:
The outside of the cover was really bad. I bought some wire brushes for my Dremel thinking they would get the job done:
Boy was I wrong. It was like moving a football field with a weed eater. I ended up using some sandpaper to get a lot of the initial junk off along with a stiff wire brush and copious amounts of brake cleaner. Then I went back with the Dremel to detail some areas and that worked out really well.
Also note that you really need to clean the inside of the cover where it sits against the rest of the rear diff. Make sure you get all of the old seal off of both the cover and the main housing. I ran some fine grit sandpaper over those sections to ensure a smooth fit and seal when I reassembled.
Here’s the cleaned up product, quite an improvement.
Inside:
Outside:
Now it’s time to set this bad boy up and get it painted. I had a simple stand I made for the kids’ couch tents, it worked nicely as a mount for the cover after a nail was added:
First/base coat done:
While that’s drying and you guys are wondering what the final product will look like, let’s clean up the bolts for the cover. I’m a huge fan of using gasoline as a cleaner… probably a little outdated but it’s how my dad and I used to clean stuff, so I do it.
After soaking and a good scrubbing here they are:
Now that those are clean it’s time to add some stencils to my cover and put the other coat on:
Aren’t those freaking sweet?!?! What’s that? How did I make those? Sorry, this is the vehicle repair thread, not the Martha Stewart thread.
For anyone about to say those designs look familiar and call foul on me let me say this: I got direct permission from Jack to use these designs since he owns them and Nicodemus was kind enough to send me the files. The TSP community is freaking awesome.
Stencils on and black paint applied:
Alright, time to let that dry and get the 20 year old spare tire checked out. My shop boss came in and showed me how it was done:
Nubbies:
These are dents in the sidewall from sitting in the rack for so long. I’m pretty sure this tire has never been removed:
Dealer PSI sticker:
OK, spare is on the truck now and I’ll test it out later. Let’s pull of the stencils and see if it worked. Left side:
Right side:
Can’t wait to see this on the truck! Ok, let’s get the cover back on. You can do this two ways, buy a gasket seal or use a product called RTV and make your own. I chose to use the RTV.
Put a bead around the cover the cover, making sure you go inside the holes:
Place the cover back on the differential and put all of the bolts back in. Don’t go super tight just yet. The RTV needs some time to set. Snug everything up and let it sit for about an hour, then come back and tighten things down.
Now things have been sitting for a couple hours. I grilled up some awesome burgers while waiting. Time to fill it up and finish the job… except… I didn’t think about the location of the drain hole and the size up the oil bottle… crap:
Looks like I have to make a quick run to the store and get a fluid transfer pump.
The pump worked great and was really simple. I was a little surprised though at the fact that I used two whole quarts of oil. Everything I read the people were saying they used just under. I looked at how much drained out and I was just over… I’m guessing I did a more thorough job than them.
I put the drain hole plug back in and took the truck out for a quick test drive to make sure it was working and also to test the spare. The wheels didn’t seize and the spare didn’t blow so it was a good day!
I’ll probably pick up some more gear oil next time I’m at the store so I can top off the diff, but for now I’m not too concerned about it.
