Mitsubishi Lancer X (CY): Rear Subframe Replacement

Part numbers are from the manufacturer's original catalogue. Check them against your VIN before ordering.

• Lift or pit with reliable supports
• hydraulic jack or transmission jack to support the subframe
• socket and wrench set (12-22 mm)
• torque wrench
• ball joint separator
• lug wrench
• penetrating oil
• container for brake fluid
• plugs for brake hoses
• Torx and E-type sockets
• marker for alignment marks

1. Park the car on a level surface, chock the front wheels, loosen the rear wheel nuts, then raise the rear of the car on a lift or jack stands. Remove the rear wheels. Disconnect the negative battery terminal.
2. Disconnect the parking brake cable from the levers and brackets on the subframe. If the caliper is in the way, unbolt it from the steering knuckle and hang it on a wire, without letting the hose carry its weight. Remove the rotor if necessary.
3. Disconnect the ABS sensors and release the wiring from the subframe brackets. If you disconnect the brake hoses, plug them, and bleed the brakes after reassembly.
4. Remove the sway bar end links and disconnect the sway bar from the subframe if it is attached to it.
5. Apply penetrating oil to all control arm and subframe bolts. Mark the position of the eccentric adjustment bolts (if any) with a marker. This will make it easier to set the alignment angles later.
6. Support the subframe with a jack or stand with a pad. Disconnect the exhaust system from its hangers if it interferes with lowering the subframe (the muffler can be lowered and held with wire).
7. Unbolt the control arms and trailing links from the subframe, or disconnect them from the knuckles, whichever is more convenient on your car. Use a separator on the lower ball joints. Do not hit the ball joints with a hammer.
8. While holding the subframe, remove the bolts that attach it to the body (usually 4 main bolts and brackets). Slowly lower the subframe and pull it out from under the car.
9. Compare the new subframe with the old one. Transfer the control arms, brackets, bushings, parking brake cable holders, and other parts to it. Inspect the mounting points on the body: if the body is corroded or deformed, the new subframe will not sit correctly.
10. Raise the subframe with the jack, align the holes with those in the body, and insert the bolts. Tighten them finger-tight first, then do the final tightening with a torque wrench. The exact tightening torque for the subframe and control arm bolts on this model was not given in the open sources I found, so take the exact value from the manufacturer's service manual. For reference only, large subframe bolts in this class are usually tightened in a range of roughly 80-130 N·m (59-96 lb-ft), but do not use this number as the final value.
11. Tighten the control arms and bushings only under load: with the car standing on its wheels, or with the suspension jacked up under the arm to normal ride height. Otherwise the bushings will be twisted and will fail quickly.
12. Install the sway bar, end links, parking brake cable, ABS sensors, calipers, and exhaust. Secure the wiring.
13. Bleed the brakes if you opened the system. Check the operation of the parking brake and the brake pedal.
14. Install the wheels, tighten the nuts in a crisscross pattern, lower the car, and tighten the nuts to the recommended torque. Check the rear suspension for unusual noises.
15. Be sure to have a wheel alignment done on an alignment rack, otherwise tire wear and unstable handling are possible.

• The subframe and its mounting are safety components that affect handling and braking
• If you lack experience and equipment, leave the job to a repair shop
• Do not work under a car supported only by a jack
• If the subframe was damaged in a collision, have the body geometry checked on a frame machine: replacing the subframe alone will not fix a bent body
• It is better to replace the subframe mounting bolts with new ones rather than reuse them