I have an 04 LX with ~271k miles that I am slowly updating as much of the rubber bushings and cushions as I can take. This is my experience replacing the 2 cushions, lower bushing, o-ring and backing washer for both rear AHC shocks. Looks like there are 2 camps, one is cut the floor pan and access from above, other is attack everything from under the car. Initially I was the in the latter, thinking it best to avoid cutting but quickly switched sides when I actually got under the car. Yes it is possible to remove the shock from under the car, but I don't know how someone could replace the o-ring and split backing washer from under the car.
I parked car on flat surface, chocked front wheels and set height control to Low. I removed the spare (didn't need too) and jacked the rear up and placed on jack stands. I removed the passenger side tire (having the many times glued back together center cap give up on me) and tried to access the 12mm bolts from the wheel well with a 12mm flex ratchet socket. Somewhere someone mentioned being able to bend the seam out of the way, on my car this didn't work. The area behind the shock bent easily however there was another panel that was joined just about the exact location needed access the bolts. The easily bent seam became very difficult to bend. So I went under the car to try from there. My LX has rear AC and there are 2 hard lines that run right in front of the area one would need to access the 12mm bolts. I was able to get the flex/ratchet end on one of the bolts but only the very tip of the open end stuck out past AC lines. I could have put another box wrench on it but was concerned any slipping would destroy the AC lines. After 30 mins of trying different positions, angles, and curses I gave up and started pulling rear seats and pulling up carpet.
I spent a huge amount of time trying to remove the absolute minimum amount of material to access the bolts and disconnect the shock. I would drill just enough, grind just enough again and again. It was a total waste of time. Save your sanity and just prepare yourself cause to really get this done you are going to end up cutting out about a 4" section of the raised ridge. The reason the large cutout is not the shock bolts but the access to get at the o-ring and backing washer. This is the cutout on the driver side I did in about 20 mins compared with the 2-3 hrs I spend on the passenger side trying to only remove the minimum amount.
I used a hole saw and drilled at an angle towards the center of the cutout to keep the pilot bit as shallow as possible. I then used a jigsaw with a metal blade and a piece of 1/4" plywood between the jig saw and the floor to keep the down stroke as far away from stuff below. The front and back ends of the hole is the trough between the ridges. Once the access hole is cut, I bled the globe and removed the 2 12mm bolts. Those were little but took way more effort to break free than it should have, and there was hardly any corrosion. After the bolts are out, the AHC fitting was carefully pried off. I used an impact with a 22mm deep socket to remove the shock nut. Then went underneath and remove the 17mm shock mount bolt. I had to undue the sway bar to make enough room to move the shock off of the mounting post. Just a friendly warning, the slightest compression of the shock will cause AHC fluid to leap out of the shock. I strongly suggest shoving a rag into the cutout whenever the AHC fitting is not attached. Once the shock was out, I taped a plug in the top and changed out the lower bushing. With the new bushing pressed in, I went back to replace the o-ring and backer ring in the AHC fitting.
Once again, the reason for the large cutout is access to the AHC o-ring. I think you could get the shock out with only a 2" hole but then you are faced with this:
This is the view from below, the AHC fitting is in a little pocket formed by the shock bracket below and floor pan above. This picture is enlarged, the hole in the shock bracket is about 1.5 inches, the opening in the fitting is 3/8" ish. The o-ring is up inside the fitting inside a groove, you can see in the pic, the ID of the o-ring is just about the same size as the hole in the AHC Fitting. With the car on jack stands it was to high to access laying down and the car was too low to sit up underneath. I had some brass pics that I tried to get at the o-ring but they kept bending. I was worried that if I went at it with a steel pic I would scratch something I shouldn't have from the akward position I was in below. At this point on the passenger side I went back up top and started removing more and more floor to get at the AHC fitting.
The AHC fitting has a section of hard pipe attached which connects to a what I can only assume is a very short or very stiff section of rubber hose. I could only rotate the fitting about 90 degrees, any more and I thought I would break something. Even at 90 degrees, it didn't want to stay so I attached a bar clamp to one of the ears of the AHC fitting, the end of the bar clamp was clamped to the 2nd row seat bracket.
From here I was able to remove both the o-ring and split backer ring using a wide variety of picks and tweezers. Getting the new o-ring installed was one of the more frustrating parts of this, only out done by getting the new backer ring in. What worked for me with the o-ring was to place the o-ring parallel to the face of the opening and then start working one part through the hole until I had the whole thing pushed inside the fitting. Then I had to use an inspection mirror and multiple picks to hold the part of the o-ring that was in the groove in place while trying to corral the part of the ring that was not in the groove.
With the split backer ring, I pulled the two free ends to make a curly/spiral shape as was able to work in one end and slowly push the rest of the ring into the groove below the o-ring. This works great for about 90% of the ring, the last 10 is tough. I had to hold the ring in place with a pick and use a flattened pick to expand the ring into the groove. This took quite a few tries until I finally got it. There has to be a better way to do this...
Once the ring and backer ring were replaced it was time to reassemble. I put mounted the shock on the lower post first, this let me get everything set up top. This step was frustrating as well, everything needs to be lined up just right in order to get enough threads of the shock above the upper washer to put the 22mm nut back on. A second pair of hands here would be useful, of course I was working along. I used a jack and piece to 2x4 to hold the upper part of the shock in place. I swear I would get everything aligned, look away for a second, and when I went back, it would have would jumped out of position. Here is a pic of the jack and 2x4, there is very little load on the jack, it is just holding the shock in place while I get the upper nut on.
Once the top nut was on, I moved the jack to under the axle and slowly lifted the side of the axle until the AHC fluid was just at the top of the strut, at this point I put reconnected the AHC fitting. I painted the exposed edges of the cutouts and taped them up for now just in case I need to access in case of leaks. The passenger side took me 5 frustrating hours. I knocked out the driver side in about an hour once I had a feel for what to do. Hopefully this helps someone who decides to venture down this road. If there is an easier way to do this please share.
I parked car on flat surface, chocked front wheels and set height control to Low. I removed the spare (didn't need too) and jacked the rear up and placed on jack stands. I removed the passenger side tire (having the many times glued back together center cap give up on me) and tried to access the 12mm bolts from the wheel well with a 12mm flex ratchet socket. Somewhere someone mentioned being able to bend the seam out of the way, on my car this didn't work. The area behind the shock bent easily however there was another panel that was joined just about the exact location needed access the bolts. The easily bent seam became very difficult to bend. So I went under the car to try from there. My LX has rear AC and there are 2 hard lines that run right in front of the area one would need to access the 12mm bolts. I was able to get the flex/ratchet end on one of the bolts but only the very tip of the open end stuck out past AC lines. I could have put another box wrench on it but was concerned any slipping would destroy the AC lines. After 30 mins of trying different positions, angles, and curses I gave up and started pulling rear seats and pulling up carpet.
I spent a huge amount of time trying to remove the absolute minimum amount of material to access the bolts and disconnect the shock. I would drill just enough, grind just enough again and again. It was a total waste of time. Save your sanity and just prepare yourself cause to really get this done you are going to end up cutting out about a 4" section of the raised ridge. The reason the large cutout is not the shock bolts but the access to get at the o-ring and backing washer. This is the cutout on the driver side I did in about 20 mins compared with the 2-3 hrs I spend on the passenger side trying to only remove the minimum amount.
I used a hole saw and drilled at an angle towards the center of the cutout to keep the pilot bit as shallow as possible. I then used a jigsaw with a metal blade and a piece of 1/4" plywood between the jig saw and the floor to keep the down stroke as far away from stuff below. The front and back ends of the hole is the trough between the ridges. Once the access hole is cut, I bled the globe and removed the 2 12mm bolts. Those were little but took way more effort to break free than it should have, and there was hardly any corrosion. After the bolts are out, the AHC fitting was carefully pried off. I used an impact with a 22mm deep socket to remove the shock nut. Then went underneath and remove the 17mm shock mount bolt. I had to undue the sway bar to make enough room to move the shock off of the mounting post. Just a friendly warning, the slightest compression of the shock will cause AHC fluid to leap out of the shock. I strongly suggest shoving a rag into the cutout whenever the AHC fitting is not attached. Once the shock was out, I taped a plug in the top and changed out the lower bushing. With the new bushing pressed in, I went back to replace the o-ring and backer ring in the AHC fitting.
Once again, the reason for the large cutout is access to the AHC o-ring. I think you could get the shock out with only a 2" hole but then you are faced with this:
This is the view from below, the AHC fitting is in a little pocket formed by the shock bracket below and floor pan above. This picture is enlarged, the hole in the shock bracket is about 1.5 inches, the opening in the fitting is 3/8" ish. The o-ring is up inside the fitting inside a groove, you can see in the pic, the ID of the o-ring is just about the same size as the hole in the AHC Fitting. With the car on jack stands it was to high to access laying down and the car was too low to sit up underneath. I had some brass pics that I tried to get at the o-ring but they kept bending. I was worried that if I went at it with a steel pic I would scratch something I shouldn't have from the akward position I was in below. At this point on the passenger side I went back up top and started removing more and more floor to get at the AHC fitting.
The AHC fitting has a section of hard pipe attached which connects to a what I can only assume is a very short or very stiff section of rubber hose. I could only rotate the fitting about 90 degrees, any more and I thought I would break something. Even at 90 degrees, it didn't want to stay so I attached a bar clamp to one of the ears of the AHC fitting, the end of the bar clamp was clamped to the 2nd row seat bracket.
From here I was able to remove both the o-ring and split backer ring using a wide variety of picks and tweezers. Getting the new o-ring installed was one of the more frustrating parts of this, only out done by getting the new backer ring in. What worked for me with the o-ring was to place the o-ring parallel to the face of the opening and then start working one part through the hole until I had the whole thing pushed inside the fitting. Then I had to use an inspection mirror and multiple picks to hold the part of the o-ring that was in the groove in place while trying to corral the part of the ring that was not in the groove.
With the split backer ring, I pulled the two free ends to make a curly/spiral shape as was able to work in one end and slowly push the rest of the ring into the groove below the o-ring. This works great for about 90% of the ring, the last 10 is tough. I had to hold the ring in place with a pick and use a flattened pick to expand the ring into the groove. This took quite a few tries until I finally got it. There has to be a better way to do this...
Once the ring and backer ring were replaced it was time to reassemble. I put mounted the shock on the lower post first, this let me get everything set up top. This step was frustrating as well, everything needs to be lined up just right in order to get enough threads of the shock above the upper washer to put the 22mm nut back on. A second pair of hands here would be useful, of course I was working along. I used a jack and piece to 2x4 to hold the upper part of the shock in place. I swear I would get everything aligned, look away for a second, and when I went back, it would have would jumped out of position. Here is a pic of the jack and 2x4, there is very little load on the jack, it is just holding the shock in place while I get the upper nut on.
Once the top nut was on, I moved the jack to under the axle and slowly lifted the side of the axle until the AHC fluid was just at the top of the strut, at this point I put reconnected the AHC fitting. I painted the exposed edges of the cutouts and taped them up for now just in case I need to access in case of leaks. The passenger side took me 5 frustrating hours. I knocked out the driver side in about an hour once I had a feel for what to do. Hopefully this helps someone who decides to venture down this road. If there is an easier way to do this please share.
