How to Replace Rear Differential Bushings

[Ike68]

The rear bushings supporting the rear differential on my 2000 Legacy GT wagon were completely shot, so this weekend I decided to replace them. I read several articles on LegacyGT and other sites about replacing the stock bushings with the Whiteline poly bushings, but I decided to go with stock replacement bushings. The decision to tackle the job myself was easy: the Subaru dealer quoted "at least" $650 in labor to do the job, plus $25 for a pair of bushings. I bought the parts .

 

Because there isn't much clearance under the car around the bushings, Subaru recommends pulling the entire rear suspension sub-frame. Going this route allows you to use a standing press to remove the old bushings and install the new ones ones. Though I've had most of the rear suspension out of this car at other times, I wasn't about to repeat that experience. Instead, I fabricated a simple bushing press from components I picked up at Home Depot: a 3' section of 1/8" C-section steel bar, three 1/2" grade-8 bolts (4", 5", and 6" lengths), and an assortment of nuts and washers.

 

I cut four 3" sections from the steel bar, center punched, and then drilled 1/2" holes through the center. I used two sections on each end for additional stiffness. If you have a welder, you might consider welding the sections back-to-back. The c-section is important for two reasons: it provides clearance for the center of the bushing so that you don't damage it during installation and it stiffens the press. Here's the result:

 

 

Put the car up on a lift or jack stands, drop the exhaust, protective belly pan, driveshaft and the rear differential. Next, remove the old bushings. Several articles mention burning out the centers of the bushings with a torch. Mine were so far gone that I just pushed the centers out with my fingers:

 

 

Removing the rest of the bushing is a pain but, if you are patient, it is not too hard. I used a hack-saw blade wrapped in a shop cloth to cut each bushing housing. A small reciprocating saw with a fine tooth blade for steel would have made this go a lot faster. Be careful not to cut into the suspension sub-frame. I also draped a shop rag over the ends of the half-shafts to prevent metal filings from eventually getting into the rear differential.

 

 

Once the cut is made, it is a simple matter to drive out the remainder of the bushing with a punch and dead-blow hammer.

 

 

The new bushings are a slightly different design than the originals. There are additional bumpers at the top and bottom (red arrows) that should keep these bushings from being over-extended, hopefully making them last longer.

 

 

It can be difficult to start the new bushings into the receiving sleeves. I found that the new bushings were about 0.025" out-of-round. I used a c-clamp to gently compress the bushing from the sides to restore them to round. I also used a bench grinder to taper the leading edge of the bushing a bit.

 

 

The bushings must be installed in the correct orientation. I used a permanent marker to mark the outside of the housing to indicate the proper orientation. There is an up-arrow imprinted in the rubber of the bushing, but you won't be able to see it once you install the press. The bushing also has a front and a back. The side that protrudes from the bushing the most faces the front of the car.

 

 

 

To install the bushing, use a rubber dead-blow hammer to lightly tap the bushing into the sub-frame, keeping it straight. Putting a small amount of axle grease on the leading edge of the bushing may be may be helpful. Install the homemade press as shown below and start turning! You will need to switch to shorter bolts as the bushing is pulled into the sub-frame.

 

 

 

If you aren't using both plates on each end, you should install the extra plate as you drive the bushing home to avoid bending the C-sections.

 

 

Reinstall the rear differential, driveshaft, belly pan, and exhaust and enjoy smooth shifting again!

[boostedgrocerygetter]

The bushings are intended to be slightly out of round to create a pressed fit.

 

Other than that good creativity on the tools.

[Ike68]

Respectfully, I disagree. The press fit comes from the average diameter of the bearing being at most a few thousandths of an inch larger than the socket in the cross-member. The resulting compression of the bearing is responsible for keeping it located. The bearing is relatively flimsy laterally: the out-of-roundness alone would not be sufficient to keep it in place.

[boostedgrocerygetter]

I'm am not sayin that the out of roundness would hold it all on its own. I am aware how these bushings work as I install roughly 2-3 sets of control arm bushings monthly.

 

All of the bushings the I install are ever so slightly out of round. Maybe subaru's are not supposed to be I don't know I work on Hondas.

[metalmodder]

I know this is bumping an old thread, but I was wondering what all you had to move out of the way to get to the diff mounting bracket. I was about to pay a mechanic $350, not including the parts, to do this on my 2k Legacy L.

[My Car]

thanks for the post. Just ordered rear dif bushings for my 2000 legacy GT. cant wait for clunk free shifting

[SubOperator]

Thanks for the writeup, bushings on my LGT surely need to be replaced. Anyone know the part # for BL/BP?

[OGOBXT]

This is one of the best and most simple time saving mods I have ever seen. I couldn't believe how big the outback subframe is, and how tough it is to remove once its rusty.. My trans shop didn't wanna touch it (told me it'd be $350-500 just to replace them. Thanks for this genius tip!

 

One thing I would like to add is you could most likely buy one piece of unistrut and cut it into 4 pieces, then may not needing to drill any holes.

[SubOperator]

Bumping this thread, thanks for the writeup. Will be doing R180 install within weeks, so definitely will address the busings as well.

[copyboy311]

Would these worn bushings cause jerky back-and-forth driving at slow speeds, such as in traffic? This is a manual transmission car. Everything is just starting to feel sloppy and not tight in the driveline. 90k miles.