Procedure - Replacement of Air Suspension to Bilstein’s with H&R coils on a 2005 4.8

[hinchcliffe]

I searched for this and couldn't get a definitive procedure so i made one and took a few pictures of the rear when i was doing it. Note that the nut sizes are from memory. Not a bad job and helps that the springs are lowering so a little shorter than stock. I'm not responsible for you so be careful.


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Took me ~7 hours total work, once I took care of one side the other was easy…
1. Fronts, remove the top nut from the absorber (19mm)
2. Then loosen the three (3) strut bearing nuts (15mm) to within a turn of coming off
3. Next remove the two large nuts from the strut body just behind the brake rotor (22mm)
4. Counter hold the sway bar link (19mm but very thin flats on the ball side I used needle nose vise grips) and remove the nut (16mm)
5. Fish wiring out of the way and back-up the rotor with a jack so it doesn’t drop
6. Cut the airline as close as you can to the bellows connection
7. Knock out the two (2) big bolts and finish removing the strut bearing nuts
8. Say good bye…
9. Install the new upper strut support with a couple nuts
10. Now take the new strut, install the rubber spring perch and spring to the strut side
11. Hold the upper rubber spring perch on the spring and feed it into the wheel well
12. Insert the two large strut screws to keep it in place and align the upper spring perch to the upper strut mount
13. Slow lift with the jack and guide the shock rod through the strut mount (I used an Allen wrench in the socket on the shock rod to help guide it in as I lifted it)
14. Take the big washer from the old strut and place it to the shock rod top and install the lock nut
15. Lower the jack and install the strut bearing nuts and the strut lower nuts
16. Then install the sway bar link nut
17. Check torque and install the wheel

Once I got through the first side the second side took 30 minutes for the front
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1. Rear, remove hose from the bellow top. Requires a small flat head to release the black clip from the brass fitting and pull up on the fitting. (this worked on one side but not the other, I ended up slitting the hose at the accumulator and pulling it from the barb fitting)
2. Then bend the gold clips and slip them off of the pins on the bellows
3. On the bottom of the bellows use a flat head screw driver from underneath and push the clip off the stud
4. Compress and pull out the bellow
5. Now, remove the top nut (18mm) from the shock absorber and loosen the three (3) shock mount nuts (15mm) (Note that these are standard shocks and do not need to be replaced you can also reuse the shock mounts)
6. Counter hold the lower shock mount nut (18mm) and take the bolt out to drop the shock. It does have a pilot on the lower shock mount which sits inside the aluminum housing (mine was stuck and I had to pry it out with a flat head screw driver carefully…)
7. Now remove the upper control arms (18mm and 19mm), both of them fully. Take the screw out of the body side and the nut off the brake side
8. Support the rotor with the jack to keep it from falling
9. Then remove the sway bar link (18mm) and the suspension level sensor arm (10mm with counter hold open end wrench) from the lower control arm
10. Install the upper and lower spring perches to the spring
11. Install a lug bolt to the bottom lug hole and press downward on the assembly
12. Carefully weave and push the spring in place making sure it lines up top and bottom. Get the lower spring perch to slip into the control arm hole
13. Now reassemble starting with the rear upper control arm at the hub and then body side, do the same for the front. Then sway bar link (I found it easier to do the sway bar link now instead of first)
14. Install the upper shock mount (reuse the mount gasket if you think you can or new)
15. Install the cover bellow and the bumper to the shock rod
16. Use the jack to position the arm and insert the shock absorber rod through the mount then insert the pilot to the arm. Install lower and upper screws and nuts for the shock. Be sure you reuse the top nut big washer to hold it in the strut mount.
17. Torque everything and reinstall the wheel

Once I got through the first side the second side took 60 minutes for the rear
Get an alignment then talk to the dealer or a friend about turning the inactive light off. When taking things apart look for wear items, I ended up replacing the control arms in the rear since I was already there and then I only need an alignment once. Watch the sensor wires and make sure you reinstall correctly

Cost ~$1500 with rear front upper control arms, (4) Bilstein shocks, (4) H&R sport lowering springs, (4) strut mounts, & spring perchs.