1997 Infiniti Q45 Rear Suspension Parts: Complete Guide to Replacement and Upgrades

The 1997 Infiniti Q45 is a full-size luxury sedan known for its smooth ride and handling. Over time, the rear suspension components wear out, leading to clunks, uneven tire wear, and degraded ride quality. Whether you are planning a DIY repair or ordering parts for a mechanic, understanding the rear suspension parts is essential. This guide covers the key components, common symptoms of wear, replacement recommendations, and tips for getting the best parts for your Q45.

Overview of the 1997 Infiniti Q45 Rear Suspension

The Q45 uses a multi-link independent rear suspension (IRS) design. This setup provides a balance of comfort and control but includes many pivot points and bushings that can wear. Key parts in the rear suspension include upper and lower control arms, trailing arms, toe links, stabilizer bar links, coil springs, shock absorbers (struts), and various bushings. When any of these parts fail, the suspension geometry changes, causing alignment issues and noise.

Common Rear Suspension Problems in the 1997 Q45

Owners frequently report the following issues:

• Clunking or knocking noises when going over bumps: Often caused by worn sway bar links or control arm bushings.
• Excessive rear-end sway or looseness: Worn stabilizer bar links or bushings.
• Uneven tire wear on the inner or outer edges: Indicates misalignment from worn control arms or toe links.
• Sagging or bouncy ride: Weak coil springs or worn shock absorbers.
• Rear end steering or instability during cornering: Bad trailing arm or toe link bushings.

If you notice any of these symptoms, inspect the rear suspension components immediately. Delaying repairs can lead to more expensive damage to tires and other parts.

Key Rear Suspension Parts for the 1997 Infiniti Q45

Control Arms

The upper and lower control arms connect the rear knuckle to the subframe. They have integral bushings that degrade over time. When bushings fail, the arm may need replacement as a complete unit because bushings are often not sold separately for the upper arms. Lower control arms also often include ball joints that can wear. OEM-quality or premium aftermarket arms are recommended.

• Upper control arms: Two per side. Common failure is the inner bushing tearing.
• Lower control arms: Also two per side. They have large bushings and sometimes a ball joint at the knuckle.

Trailing Arms and Toe Links

The trailing arm runs longitudinally from the subframe to the knuckle, controlling fore-aft movement. The toe link (or lateral link) adjusts toe angle. Both have bushings that can cause steering instability when worn. Replacement is straightforward but alignment is required afterward.

Stabilizer Bar (Sway Bar) Links and Bushings

The rear stabilizer bar reduces body roll. The links connect the bar to the knuckle, and the bushings mount the bar to the subframe. Worn links cause a clunking noise. They are inexpensive and easy to replace. Use OEM or quality aftermarket links.

Shock Absorbers (Struts)

The Q45 uses separate shock absorbers from the coil springs. Over time, shocks lose damping capability, resulting in a bouncy ride and poor handling. For the 1997 model, you can choose standard replacement shocks (KYB Excel-G or OEM) or performance shocks (Bilstein, Koni) for improved control. The rear shocks are typically replaced along with the upper mount and bellows if damaged.

Coil Springs

Rear coil springs support the vehicle's weight. They can sag over time, especially if the car is often loaded or driven on rough roads. Sagging springs lower the ride height and cause bottoming out. Replacement springs should match the original ride height unless you want a slight drop. Moog or OEM springs are reliable.

Bushings and Mounts

Many suspension bushings are pressed into arms or sold separately. Common replacements include subframe bushings, knuckle bushings, and shock mounts. Polyurethane bushings offer longer life and tighter handling but transmit more road noise. Rubber bushings provide OEM comfort.

Replacement Tips for 1997 Q45 Rear Suspension

Replacing rear suspension parts on this car is moderately difficult. Here are some practical tips:

• Alignment required: After replacing any arm, link, or tie rod, you must have a professional 4-wheel alignment. Otherwise, tire wear will be rapid.
• Penetrating oil: Use a good penetrating oil on bolts a day before to prevent breaking rusted fasteners.
• Torque specs: Tighten all bolts with the suspension loaded (on the ground or with jack under the knuckle) to avoid preload. Torque values: control arm bolts typically 80-100 ft-lbs, trailing arm bolts 60-80 ft-lbs.
• Check condition of all bushings: While replacing one part, inspect others. It saves labor to replace worn bushings at the same time.
• Consider complete kits: Some manufacturers sell full rear suspension rebuild kits that include all bushings, ball joints, and links. This is cost-effective if multiple parts are worn.

OEM vs. Aftermarket Parts: Which Should You Choose?

For the 1997 Q45, you have several options:

• OEM (Infiniti genuine) parts: Exact fit, OE quality, but expensive. Best for control arms and bushings that need durability.
• Premium aftermarket brands (Moog, TRW, Lemforder, Febi Bilstein): Often match OEM quality at a lower price. Good for control arms, tie rods, and bushings.
• Budget aftermarket (Mevotech, ACDelco, Dorman): Less expensive but may have shorter lifespan. Suitable for links and shocks if you plan to keep the car short-term.
• Performance brands (Bilstein, Eibach, Koni): For shocks and springs if you want a sportier ride. Be aware that lowering springs may require different alignment specs.

Avoid no-name parts from unknown sellers; they often fail quickly and can cause safety issues.

Step-by-Step Replacement Guide (Overview)

While a full guide is beyond this article, here is a general order for a rear suspension overhaul:

1. Safety: Chock front wheels, lift and support rear axle on jack stands.
2. Remove rear wheels.
3. Remove stabilizer bar links (2 bolts each).
4. Remove shock absorbers from lower mount and top mount (may require trunk interior access).
5. Remove coil springs (compress with spring compressor if necessary).
6. Remove trailing arms and toe links (unbolt from subframe and knuckle).
7. Remove upper and lower control arms (may need to disconnect parking brake cable and ABS sensor).
8. Install new parts in reverse order, using new hardware.
9. Torque all bolts to spec with suspension loaded.
10. Reinstall wheels and lower car. Drive to alignment shop.

Final Recommendation

For most owners, replacing worn rear suspension parts with OEM-quality aftermarket components (like Moog or TRW) offers the best balance of cost and reliability. Focus on the parts that cause your symptoms: if you hear clunks, start with stabilizer bar links. If the ride is bouncy, replace the shocks. For alignment issues, replace control arms and toe links. Always replace bushings in pairs or full sets. After repairs, a professional alignment is mandatory. With proper maintenance, your 1997 Infiniti Q45 will ride smoothly for many more miles.