Hey guys,
I am copying and pasting the below which is my original content that is posted on other forums 
I made this for my GC8 but in most cases it will also suit SF Foresters and others - you will need to double check your Rear Diff Bush style
So without Further adieu Here is my pre written DIY that has been posted in a few other locations
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Hey all,
Did a little DIY on the weekend - been meaning to get to this for ages, i didn't take many pictures of the process because i didn't think i would get this far but now im done and im happy!!!
Being 18 years old, my 98 GC8 rear diff bushes began to get flogged out and noisy, after putting in the Hardrace engine, tranny and pitch mounts i was over the moon in the lack of movement in the drivetrain but still felt there was a little more to be desired - and this was it - now shifts are smooth, down shifting/rev matches are perfect!!!
I will use pics from google where possible, but try to explain best as possible.
the diff bushes wearing is a common issue with the GC8 and short of removing the rear subframe, this was the only feasible resolution. which makes this harder is that there is no diff inserts to suit the GC8 available.
Be warned, i am not responsible for any damage to your car as a result of installing these/installation issues!
This is probably one of the easiest mods i have done to the car to date and yielded the best results - there is no noticeable NVH - well i dont notice it - Acceleration is straight on, taking off from a stop feels fantastic and as above, the rev matching feels amazing - i cant recommend doing this highly enough!!!
Lets begin;
Parts and tools:
- Jack
- 17mm spanner/socket
- breaker bar/ratchet if applicable
- Superpro Rear Differential Support Mount 'Void Filler' Bushing Set SPF4297K - These are made for newer rexies - see below
- sharp knife for trimming to fit
- Grease (preferably lithium grease/bushing grease)
- washers large enough to cover majority of diff bush insert - i grabbed mudguard/mud flap washers from bunnings - my kit did not include the washers
- step drill bit/large drill bit to widen the hole in washer to suit diff bolt diameter
My diff bushes may be different to yours as i have a early build 98 GC8 - not sure if there are any differences see pic below from google of bushes similar to my ones
1. Get the back in the air, high enough to work your way around under the car (i used DTM low ramps for sufficient room)
2. Jack up the Diff slightly so there is an even gap in the diff bush
3. Prepare washers by widening hold in center to fit over duff bolt diameter
4. prepare diff inserts, this may take a little bit of testing and trying - cut bush inserts narrower and thinner to slip inside diff bushes - i made mine just narrow enough to fit in voids and just thick enough to need to be forced into place
The red spots in this image is pretty much the cut lines, you want to cut down these until you hit the bottom of the insert without cutting through the insert - i will try and take mine off to show the detail a little better
Cutting is necessary as there are to my knowledge, no inserts to suit GC8's (and i did a crap load of looking) - these inserts are made for newer 08+ rexies and will not suit GC8's in their standard form.
5. remove nut from diff bolts using 17mm spanner/socket - these are done up FT from factory (F**king tight) so prepare to need some decent force
6. grease up bush and attempt to slide in
7. this may require a great deal of force to get in - i ended up greasing the crap out of the bush, putting it into place, slipping the washer back over and using the nut/washer to force the insert in. i then backed this off all the way to ensure that the insert was seating in the bush correctly
8. Reinstall nuts and tighten down to FT specs.
9. Finished install - see pics
10. Take the car for a drive and enjoy.
11. Drive 100kms and double check tightness of nuts
This also removed the knock from the rear of my car. If anyone is interested in getting these but is concerned about modding the bushes, i can probably buy a few of these and cut them into shape and test on my own car, i can also provide suitable washers etc and probably do them for $50 shipped to your door if there is any interest.
Please provide any feedback
Cheers
