As you may already know, I am the owner of a 1993 Subaru Impreza LS (GC5). While returning from a trip to San Francisco to attend the Power to the Peaceful festival (which was extremely underwhelming this year) in celebration of the three-year anniversary of my relationship with my lady Anna-Maria, a loud clicking noise was to be heard while accelerating and turning left. I easily identified this problem as a failure of the left front axle (I could tell by feeling the vibrations as much as by hearing the sound in this rather small car) and proceeded to research the issue of repair.
I had recently performed an Axle replacement on a 1998 Nissan Sentra for a friend (and for money, of course) and so I felt more than capable of tackling this task in a short period of time. I have long been a Nissan enthusiast (beginning with my purchase of a 1980 280ZX some ten years ago) and so I took that job on readily. It turned out to be somewhat difficult, but not egregiously so - my main problems laid in having to separate much of the front suspension in order to make the replacement. However, Nissan thoughtfully used a circlip retainer at the inner spline (which enters the transaxle) so that was about the worst of it.
Subaru's design is superior in some ways, especially in the area of the suspension work. It is only necessary to remove the two bolts which fasten the strut housing to the knuckle; I then tied the knuckle forwards with a piece of wire and was able to remove the outer spline from the hub. The ABS sensor is integrated into the hub, which simplifies the axle somewhat and made this more possible. But what truly makes this possible is the design of the axle, which has a female spline at the inboard end. Unfortunately, this means that should a circlip fail it is theoretically possible for the axle to disconnect from the transmission without the suspension being damaged at all. Thus, Subaru used a driven pin instead of a circlip.
Luckily, it is not necessary to open the transmission to remove the pin - it is in fact just outside the transaxle case. However, you will need to drive the pin out with a drift. I fashioned one from the screwdriver I broke trying to remove the captive nut from the axle (I ended up actually removing and installing the nut, which is crimped into a keyed slot on the end of the outer spline, with a nail set) by spending a little time on it with a bastard file. I then tapped this drift through the hole and drove out the pin using a light hammer. An actual hardened drift would be superior, but my makeshift tool performed the job adequately.
The total time to perform this job was about two hours, including the time I spent running around looking for tools. Due to the design of the transaxle, no gear oil was lost from the differential while replacing the axle. This makes the job a fairly easy one to perform in the field, requiring the following tools:
- Socket wrench with breaker bar
- Torque wrench
- 17, 19, and 32mm sockets
- 2" or 3" extension and adapters to match all sockets to both wrenches
- 17mm box, open, or combination wrench
- Drift and hammer
- Nail set or small chisel
- Factory jack, or hydraulic jack and stand
The front axle will fit either side on the GC5. The above tools are mandatory for a long list of jobs on the vehicle and as such should be included in your kit in any case. The front axle replacement is so simple it actually isn't detailed in my repair manual... If you forget to break the 32mm axle nut loose before raising the vehicle and removing the wheel, as I did, you can do it as a one-man job (if it's on the driver's side) by putting a long breaker bar (in my case, the handle of my aluminum jack) on a socket wrench so that you can put your foot on the brake and crank on the nut at the same time. Short form: break everything loose with the car on the ground! Of course, if you have alloy wheels as I do, you may have to remove the wheels to remove the center cap anyway...