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Replacing all the rear bushings in a 94 Legacy SS

Posted: Fri Mar 28, 2008 4:52 pm
by EtchyLives
So begins my project. A few months ago I bought all new Group N bushings from Rallispec. Then it got cold. Since it's warming up I'm getting ready to take the entire rear end apart and put in the new bushings.

Here is the list of bushings you'll need.
RST-2020R STi Hardened Bushing - Front Control Arm Rear RH

RST-2020L STi Hardened Bushing - Front Control Arm Rear LH

RST-2021 STi Hardened Bushing - Front Control Arm Front (2 x)

RST-2023 STi Hardened Bushing - Trailing Link Front (2 x)

RST-2024 STi Hardened Bushing - Trailing Link Rear (2 x)

RST-2025 STi Hardened Bushing - Lateral Link Outer (4 x)

RST-2026F STi Hardened Bushing - Lateral Link Inner Front (2 x)

RST-2026R STi Hardened Bushing - Lateral Link Inner Rear (2 x)

RST-4153 STi Hardened Rear Diff. Mount Bushing (2 x)

RST-4150 STi Hardened Rear Diff. T-bar Bushing (2 x)

RST-2022 STi Hardened Rear Crossmember Bushing (4 x)

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See all those little red circles? Those are all the bushings that I'm replacing.

I've already ordered replacement hardware for every nut, bolt and washer in the rear end, I've got a drive to crack the diff drain plug, I've got a small awl and a 4.8mm rod to push the chamfered pins out of the differential, I've got fluid for the diff and should have enough PB blaster and assorted sockets to get the job done. What I'm looking for are tips, tricks, and experiences from people that have done this to help me along.

I'm also wondering what size socket I'll need to pull the hubs off. Is it a 32mm socket?

By all accounts the long bolts that connect the trailing arms to the knuckles are the biggest PITA and I should expect to be breaking those.

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This is a list of all the hardware I ordered for this project. Red boxes indicate ordered parts. The numbers outlined with the red box on the far right are the quantities. Total cost for me with a 20% MNSubaru discount was ~$128 at Morries Minnetonka Subaru. It wasn't cheap but if I'm going to do this I'm going to do it right.

I took the list above in to the parts dept and they had the parts ordered in about 10 minutes. It makes their life that much easier.

Thanks,
-Greg

Posted: Fri Mar 28, 2008 5:24 pm
by Legacy777
Greg,

Just to give you fair warning....

You will probably have to drop the rear crossmember to replace those bushings that hold it to the chassis. I chose to use the rear subframe locks instead.

Any bushing with a metal collar will be a huge pain in the ass to replace. Even with a press, it's still a pain. The front subframe will have to be removed, the trailing links have a metal collar bushing in the front, same goes for the rear diff mount.

Not to put a damper on your project, but whiteline makes "filler" bushings for the front subframe, and do work well. The subframe locks work well in place of replacing the rear subframe bushings.

I want you to be aware of what you're getting yourself into. I spent nearly an entire day during my 5spd swap process trying to get the sti bushings into the rear hub. I never got them in during the swap. I ended up using a tool that one of the guys on nasioc had made for this specific purpose. Plus the guy I brought the trailing link bushings to...with the metal collar basically told me.....he had to make special adapters/collars, and to not tell my friends where I had it done.

Here are some pictures of the tool
http://www.main.experiencetherave.com/s ... ol/images/

Info
http://www.main.experiencetherave.com/s ... op_man.doc

http://www.main.experiencetherave.com/s ... rview1.jpg
http://www.main.experiencetherave.com/s ... rview2.jpg
http://www.main.experiencetherave.com/s ... stall1.jpg
http://www.main.experiencetherave.com/s ... stall2.jpg
http://www.main.experiencetherave.com/s ... stall3.jpg
http://www.main.experiencetherave.com/s ... moval1.jpg
http://www.main.experiencetherave.com/s ... moval2.jpg

Anyway....

You should be fine on those long bolts if you use pb blaster

Posted: Fri Mar 28, 2008 6:06 pm
by 93forestpearl
Hey Greg, its Dan, or piddster as you know. I've done all the rears and it was a treat. If you know someone with a balljoint press, that will be your biggest friend. I used a hand press at school and would have been dead in the water without it.


I had to replace both the long bolts for the lateral links on the knuckle. Minnesota winters are not nice to them. The dealer in Duluth told me they have trouble with 2 y/old cars.

Bushings with a metal collar come out OK if you have an air chisel. Its not for the faint hearted though.

Posted: Fri Mar 28, 2008 8:11 pm
by EtchyLives
I've got a hand press and a line on some folks to press in the metal-collared bushings. I have those for the FCAs, too.

Josh,

Thanks for the input. I didn't get the hub bushing (God Lord that looks awful) and I'll consider picking up those whiteline bushings for the filler and I already intended to drop the rear subframe anyway. I have to put in my LSD so the diff was coming out anyway.

Which subframe locks do we use? The WRX ones? I saw the holes the last time I was under the car and thought about ordering a set but some searching for part numbers left me more confused than when I started.

Thanks again for all the input. I suppose I should go out and start jacking up the Legacy. I have the 32mm axle nut socket so I can truly begin. I guess I'll be driving the M5 for awhile. Shucks.

-Greg

Posted: Fri Mar 28, 2008 8:18 pm
by Legacy777
Greg,

Yeah you did get the hub bushing. At least you circled it on your diagram. I can't see the number, but bolt 31 goes into it. It's the rear trailing link bushing. If you go look at the car, you'll see what I'm talking about.

As for the subframe locks, I was not aware that there were different part #'s. If you look at my swap write-up, I've got all the part #'s

http://www.surrealmirage.com/subaru/swa ... suspension

Posted: Fri Mar 28, 2008 8:22 pm
by EtchyLives
Legacy777 wrote:Greg,

Yeah you did get the hub bushing. At least you circled it on your diagram. I can't see the number, but bolt 31 goes into it. It's the rear trailing link bushing. If you go look at the car, you'll see what I'm talking about.

As for the subframe locks, I was not aware that there were different part #'s. If you look at my swap write-up, I've got all the part #'s

http://www.surrealmirage.com/subaru/swa ... suspension
Crap. Time to go buy some more hardware.

Posted: Wed May 14, 2008 4:23 pm
by EtchyLives
I finished this project last Friday and have been enjoying my car all weekend. Everything is so much stiffer and the two things that remain to be done are reduce chassis flex and possibly change out spring rates. This is where I need some advice.

1. Chassis Flex: I've got bids in on front and rear strut bars and a Turbo H-brace. Since the BC chassis is a noodle compared to the GD and later chassis I am looking for any and all upgrades I can get my hands on. Fender braces are the next option I can think of but the only ones I can find are the GT-Spec braces and those are pretty expensive. Beefy? Yes. But I'm trying to keep this a budget project so if anyone has a link to braces similar to the $60 ones you can get for the WRX I would appreciate the link. Also, I'd like recommendations to any other chassis stiffening components you can think of. Most parts that fit a GC will fit this car.

2. Spring rates: I'm running the 8" GC coilover sleeves on AGX struts and from what I can tell the R-compounds have maxed those out. Is it possible to get another set of sleeves from GC that have higher spring rates? Are there springs out there that are stiffer with a similar drop in ride height? I have no desire to go to a full coilover setup. I also need to either get some Group N Tophats or camber plates since I'm still running stock tophats.

3. Power: My suspension and tire setup has overcome the power of the car. Even at 5k RPM with boost at peak (11.5psig) and WOT I can feel the engine loose power mid-corner. Too much grip. I need more power, cap'n. If anyone has a line on some EJ25 DOHC heads I'm now in the market. Matt Monson, you are officially on notice that I will be coming to the Ghetto Garage later this summer to do some power upgrades. FWIW I'm running a stock engine with VF-8, JDM Slanty IC, MBC set to 11.5psig and a 3" TBE that is reduced at the muffler to the stock exhaust diameter (2.5" IIRC). My DP is an HKS with the flat flange. I'm also running a 91 VLSD in the rear.

As for the R888's: When I get out to a safe place (Track, Auto-X) I'll give a full report. As it stands right now I have been able to break them loose exactly once. A long sweeping exit ramp consisting of two turns (2nd is sharper than the first) with a 3-lane exit. I was able to break the tires loose by entering the 2nd turn near the top of 3rd gear. After I hit apex (late. It was glorious) and started to exit the corner I was able to get a bit of tire spin. However this was at about 8pm and the ambient temps were around 55 degrees. When the pavement is warm and the tires are hot I don't see this happening.

Suspension mods include the following: AGX with GC coilover sleeves (8") set to 4 in the front and 6 in the rear with stock tophats, Group N Bushings throughout the whole car minus the ones in the rear knuckle (I'm going to have to punch the stockers out with an air chisel and replace them with poly bushings), Whiteline Adjustable RSB set to the softest setting (I need to play with this. The car seems to be pretty neutral with a slight tendency for U/S), Tribeca sway bar up front with poly bushings, Whiteline Steering Rack bushings, and Kartboy endlinks all around.

I'm running 205/50-15 Toyo R888's on the stock 5-spoke wheels. I decided to go with the smaller diameter for four reasons: sidewall height, weight, cost, and tire options. Sidewall height of 50 is much lower than 65 and this added quite a bit of stiffness. The tires are much lighter than the 65's too. I like the reduced cost of running 15's and since 205/50-15 is a Miata size I can get almost any performance tire imaginable (including these R888s).