This writeup is for the early transmissions, [1990-2001 Impreza and Legacy], but should also work with the GDs' linkages.
After replacing the shifter linkage mounts on my 96 Outback Sport with Kartboy polyurethane mounts, the shifter was still noticeably 'floppy.'
About a week later, I was codriving a 93 Legacy Turbo [we have the same linkages] and the problem bushing [See the circled "11" in the exploded shifter linkage drawing] came out while on a Rallycross run.
Shifting into first and second became impossible, and we had to jerry-rig the linkage with zip-ties just to get the car home.
We decided to find a permanent solution to our cars, so this is what we did.
**I would suggest replacing the linkage mounts with polyurethane like I did, the old rubber gets brittle and creates additional slop in the shifter. However, if you are on a budget, this is a quick, effective fix. There will be a noticeable increase in shifter harshness and noise as we've replaced a rubber bushing with a metal part.**
Unfortunately, the bolt that holds this piece in place hits the transmission housing during removal, so disassembly of the linkage is necessary.
The most difficult and time consuming part is removing the 'knuckle' [Part 29 in the drawing] from the shifter arm that goes into the tranny. It is connected with a spring pin inside a spring pin [See part 19]. You must first find a drift or rod that is the same OD [Outside Diameter] as the inner spring pin. I made a piece out of a drill bit inside a very small sized [~6mm] socket and some 3/8 extensions.
After that is done, you can remove the outer spring pin. It's not that easy, but once it's done, you can remove the knuckle [Part 29]. Vance's knuckle slipped right off as soon as the spring pins were out. Mine, however, was rusted to the tranny rod >_< I did the install as well, it was just a major PITA compared to Vance's. Getting that thing off of there makes things much, much easier.
Go to your nearest hardware store and bring the knuckle [Part 29] and the other part of that assembly [Part 26].
* A Bolt and nut to replace the old bolt
* A metal sleeve to replace the bushing.
* A few washers that fit over the 3/8" bolt [I used three (3)]
I'll look up the part dimensions when I get home, but the bolt was a 3/8" diameter. Make sure to get a bolt with a long shoulder that is about as long as the stock knuckle length. We had to cut our threads down to not interfere with the transmission housing.
Part 26 has two sized holes [One is larger for the shoulder of the bolt], and you'll need to drill the smaller hole out to fit the larger, new bolt. If you get confused when the female part [Part 26] is off the car, the side with the nub with the hole for the spring [Part 20] is the side that needs to be drilled.
I put the female knuckle [Part 26] in a vice, drilled it out, and installed the bolt, sleeve, washers, and nut while it was in the vice. After it was all together, I made sure it was tight but could still rotate a bit, then cut off the excess threads on the bolt.
Here is the fully modified knuckle assembly [Parts 29 and 26 attached with the new bolt/metal sleeve setup]
"Installation is the reverse of removal"
The other knuckle's bushing [Part 13] was not deteriorated in either mine or Vance's linkages, for some reason, and does not need to be replaced.
I only had to re-install the outer spring pin, it wasn't going anywhere so I think the inner spring pin is unnecessary.
Enjoy your tight shifter.