[sekifaca16]

Does anybody know how difficult it is to replace a rear differential cover?? (see pictures)
I month ago I replaced the rear differential fluid and unfortunately overtightened the drain plug which cracked the cover just enough for oil to slowly leak.
I was getting ready to replace it (part is arriving in a few days) and was hoping the steps were:
1. Put some support under the differential
2. Unscrew the 2 big bolts holding the differential to the sub frame
3. Unscrew the 8 small screws holding the cover to the differential body
4. Put everything back together.

But as you see from the pictures, space between the sub frame and the cover is millimeters. So, i'm hoping one of you did this already and knows the steps. I'm really hoping "oh, it's super easy! and I don't have to tow it to the mechanic.
Any advice is appreciated.
I bought the replacement: cover, 8 small bolts holding the cover because they are super rusted, and the gasket.
Thanks!

 

[CO17Forester]

You have a good plan.

The differential is lightweight making it easy to support while replacing the cover.
If you were removing the diff from the car I would recommend a transmission jack, I found it helpful when reinstalling the CV shafts.

On edit: I think you will need to unbolt the driveshaft to move the diff forward.

I took my diff out to make it a locker and so far I am very happy with it. As to why I I took it apart.
I used some Right Stuff on the metal gasket, just a little to help it seal. Leaks make me nervous.
The rear cover bolts on a manual is 21.8 ft-pounds, 18.4 ft-pounds for the CVTs.

Should be a fun project.

 

[sekifaca16]

@CO17Forester Oh man...i dont know if I can call it a "fun project" yet. We'll see.
So, you think if I unscrew the drive shaft I will be able to move the diff forward and cover will be able to come out?
I am so nervous about all those rusty screws down there. I just know one of them will not cooperate. Thx!

 

[CO17Forester]

Getting a good install on the gasket will be the hardest part of this project. With the rust in the photo I would grab a can or two of Free All.

Once you unbolt the driveshaft, the front diff mount and the 2 nuts of the rear diff mount, the only thing holding the diff in the car is the CV-shafts. By design the CV shafts will allow the diff to move around some.

My transmission jack weighs 140 pounds and moving it in the dirt is a challenge. Once I had it in place it did make a good work platform for holding the diff while I reinstalled the axles. Taking the diff out would have been easier without the jack, but you could use a place to rest the diff.
That is the only time I've remove a diff in a Subaru, so I have not tried any other ways to support the diff.

The bolts are soft and easy to drill if you need to ease one out.
A cheap tap & die set is useful for cleaning and repairing threads on many projects.

I usually mess up when I try to rush things.
I mostly work on my car for my own enjoyment, but sometimes I have to remind myself to slow down and enjoy the moment.

 

[sekifaca16]

@CO17Forester Thanks so much! I got the Free All...lol
Edit:I just attached the picture to make sure I understand you. So, you're saying I have to unscrew:
1. Driveshaft
2. Two bolts on this link
3. Two big bolts holding the Cover Right?

 

[CO17Forester]

You just need to move it a little to replace the rear cover and taking those out will give you the space. In my service manual they combine the remove and install instructions for both types of differentials and has more steps than you need for this project. You have the VA type diff, I'll attach a pdf file below with the procedure. What I call a CV the manual calls a DOJ for Double Offset Joint.

You don't need to remove the shafts at this time. I didn't remove the tires since I had the car parked on ramps and the exhaust pipe was not in my way.

2014-2018 Subaru Forester Rear Diff Removal and Install.pdf

 

[sekifaca16]

@CO17Forester Thank you so much.
I also called the Subaru Parts to make sure they have the bolts just in case they get stripped and they do so I'm feeling better about tackling it.
Thanks again for the PDF.