Progress 22mm/24mm Rear Sway Bar and Tie Bar Installation (RSX / EP3 Civic Si)

Crack the rear lug nuts loose while the wheels are still on the ground, but leave them threaded on. Put the transmission in first gear and chock the front wheels so the car cannot roll. Raise the rear at the factory jack point, a hook in the center of the rear underbody, then transfer the weight onto two jack stands set on the pinch-weld seams running along each side; those seams stand slightly proud of the surrounding floor. Never trust the jack by itself to support the vehicle while you are underneath it.

With the car resting on the stands, take off both rear wheels and keep each one with its own lug nuts so nothing goes missing. This exposes the factory sway bar, its bushing brackets, the endlinks, and the lower control arm bolts you will be working with.

Spray penetrating oil on everything you are about to disturb: the endlink nuts, the four bushing-bracket bolts, and the lower control arm bolts. WD-40 does little on rusted hardware; owners strongly prefer PB Blaster, applied generously and, on badly corroded cars, left to soak overnight. Salt-belt endlink studs can seize so hard that people have cut them off with a hacksaw, so this step is often the difference between a quick job and a fight.

The factory endlink is essentially a ball joint, so its stud spins freely; turning the nut on its own just rotates the whole stud. Hold the stud still with a 5mm hex key inserted into the end of it, then loosen the 14mm locknut with a 14mm wrench. Leaving the suspension hanging puts a slight bind on the joint that helps keep it from spinning. Separate the endlink at its lower mount to the car, not at the upper mount to the bar. If you are reusing the factory endlinks with a 22mm bar and not adding the tie bar, you only need to free the top of each endlink from the sway bar.

Undo the four 12mm bolts that clamp the sway bar bushing brackets to the rear subframe. With the brackets and endlinks released, lift out the thin factory bar. Clean the subframe mounting surfaces with brake cleaner before installing the new parts.

Slide the new polyurethane bushings onto the Progress bar, first packing the inside of each bushing with the supplied grease; use a grease that resists water so it will not wash out and cause squeaks. Push both bushings up against the welded collars on the bar that locate them, then set the larger Progress brackets over the top of them so the assembly is ready to bolt down.

This step applies only if you are also installing the Progress reinforcement tie bar; skip it when reusing the factory brace. Remove the two 18mm lower control arm bolts, one per side. Expect the control arms to drop and shift out of position once the bolts are out. Build each new fastener from the threaded tip in this order: 19mm bolt, spacer, tie bar, large washer, then the bolt head. To align the holes, put your jack under the spring/shock and raise it until the control arm, tie bar, and subframe holes line up so you can see straight through; a pry bar helps with the last bit. Thread the 19mm bolts in with a 19mm socket but leave them loose for final torque later.

Raise the assembled sway bar to the tie bar and align the four mounting holes. At each hole the stack runs large washer, then small washer, then a 13mm bolt; run them in with a 13mm socket.

Thread the two halves of each heim-joint endlink together with the adjustment locknut captured between them. Set the male heim into the female so the endlink stands as close to vertical as possible at ride height; that ride-height alignment, not a fixed thread depth, is the correct target. On the 24mm adjustable bar, pick the stiffness setting now: the inner hole nearest you is the stiffer position. Bolt the endlinks on with the four 14mm bolts and the kit spacers and washers. Top stack: 14mm bolt, washer, spacer, heim, three spacers, sway bar, washer, nut. Bottom stack, through the rear suspension mount: 14mm bolt, washer, rear suspension, two spacers, heim, one spacer, sway bar, washer, nut. The kit supplies roughly 14 spacers and four washers, though counts vary slightly between kits.

Progress publishes its own torque figures, which differ from Honda's factory values; follow the Progress instructions for the bar hardware. Before final tightening, load the suspension back to ride height by refitting the wheels and lowering the car, or by jacking the hub up to simulate ride height, so nothing shifts and loosens after the car settles. Torque the tie bar bolts, the endlink nuts, and the bracket bolts. This hardware sees very high load and is known to back off; several installers lost bolts within a few weeks. Use fresh self-locking nuts as the service manual calls for, tighten firmly, and re-inspect everything after a few days of driving. Lower the car and refit the wheels.