Author Topic: Converting rear air suspension to coil springs on a Crown Victoria  (Read 2367 times)


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I made this post for another forum, so for the hell of it I'll post it in this dead section.

The backstory here is last week my driver side air spring sprung (no pun) a leak...

Okay, so here is how it went down. The car was sagging so bad that it bottomed out on my driveway, unless I approached it at an angle.

The old air spring was definitely shot and did not deteriorate overnight. If I had noticed this sooner, I would done this job long ago.

Getting the old springs off was relatively easy. With the bags deflated (as the blown one obviously was), the bottom popped off and the top was held in place by this clamp like pin.

Upon removing said clip, the bag sorta falls revealing the air solenoid and electrical connector. The electrical connector is hard to see, but does not need to be disconnected. I did so to make it easy to twist off the solenoid, as seen here. I then reconnected the solenoid to the electrical connector to keep it clean and dry.

The other side was not far behind, but it was a bit harder to remove because there was still air pressure. I managed to trick the system by elevating the rear end, turning the system back on, then dropping the rear end. This makes the system bleed out air to bring the car back to normal ride height, obviously nothing would move here but less air mean easier removal of spring. Other than that, it was the same scenario.

Removing the old shocks was tedious. The lower mounts were a breeze, but there is almost no clearance to remove the upper shock mount bolts.

And even when I did manage to wedge a ratcheting wrench in there, preventing the shock was free spinning with the wrench meant clamping a vice grip so the frame of the car would hold it in place.

I have read that in the rustbelt, one way of removal meant a sawzall or oxy-acetylene torch, which is dangerous on HPP cars due to the air lines for the bags. Another way is drilling holes in the trunk big enough to get a socket in. Luckily, with some patience and a lot of cussing, I got mine out in one piece.

New springs and new shocks with new hardware

Spring mount with and without spring insulator. I bought a set because I was told the springs did not come with any. Well they did, but the ones I bought ended up being better (not as hard, more malleable).

At this point I kinda slacked on pictures. The spring compressor I rented from oreilly was not the friendliest tool, but I can tell it was made for coil-overs.

Shocks and springs installed

And ride height back to normal. Actually, it sits higher than before the leak. In fact, I think it's the highest it's ever sat under my ownership.

Those upper shock mounts still have my wrist sore, other than that it was a fun project. The car feels tighter now and the rear lost it's squishiness. I can't say it soaks up bumps as well as the air springs, but it still holds a smooth ride. It also holds the rear in place through corners better. Next will be the front end.
Formerly DoD.


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Re: Converting rear air suspension to coil springs on a Crown Victoria
« Reply #1 on: April 06, 2014, 11:21:51 AM »
Nice. The rear springs will break in within a few months and the ride height should come back down just a bit. And yeah as far as using a sawzall or torch... You made the right call by being patient. A torch should be the very last resort. There's almost nothing that can't be taken apart with regular tools of you do it right. Rust penetrant, patience and time will get it apart if it's at all possible. Took about a half hour per bolt to get my leaf springs off my XJ. Little bit of PB Blaster, rock the bolt with a breaker bar, more PB, rock it more, etc. eventually I got a full 360 turn out of it and was ok to use the impact the rest of the way.