The Dinan Suspension Upgrade is a highly regarded modification for the Mercedes-Benz CLA45 AMG, delivering sharper handling, reduced body roll, and a more planted feel without sacrificing daily comfort. This comprehensive guide walks you through every step of the installation process, from gathering the right tools to performing the final test drive. Whether you’re a seasoned DIY mechanic or an enthusiast tackling a major upgrade for the first time, these instructions will help you achieve a professional-grade installation.

Overview of the Dinan Suspension Upgrade

Dinan is known for engineering performance components that maintain factory-like reliability. Their suspension kit for the CLA45 AMG includes matched springs and dampers tuned specifically for this chassis. The upgrade typically lowers the ride height by 15–20 mm, improves cornering stability, and reduces nose dive under braking. It’s an ideal choice for drivers who want sharper responses on track days while retaining acceptable ride quality for daily commuting.

Before diving into the installation, it’s important to understand that this job requires mechanical confidence, proper tools, and a clean workspace. If at any point you feel uncertain, consult a professional mechanic. For official product details and warranty information, visit the Dinan website.

Tools and Materials Required

Having everything ready before you start saves time and prevents frustration. Below is a detailed list of tools and supplies you’ll need:

  • Jack and jack stands (minimum 3-ton capacity; always use stands, never rely solely on a jack)
  • Torque wrench (capable of reading in both Nm and lb-ft, with a range covering 30–150 Nm)
  • Socket set (metric sizes from 10 mm to 21 mm, including deep sockets)
  • Wrenches (combination wrenches and a hex-key set for some fasteners)
  • Spring compressors (screw-type or hydraulic; essential for safe spring removal and installation)
  • Dinan suspension kit (verify contents: front struts, rear shocks, springs, bump stops, and any included hardware)
  • Safety glasses and mechanics gloves
  • Penetrating oil (e.g., WD-40 or PB Blaster) for stubborn bolts
  • Breaker bar (for loosening tight fasteners)
  • Pry bar or large screwdriver (to separate components if needed)
  • Shop rags and a torque specification sheet (print the factory torque values for suspension bolts, or refer to a reliable source like Mercedes-Benz technical resources).

Preparation Steps

Preparation sets the stage for a smooth installation. Follow these steps before lifting the car:

  • Park the vehicle on a flat, level surface. Concrete is preferred over asphalt.
  • Engage the parking brake firmly and chock the rear wheels if working on the front first.
  • Put on safety glasses and mechanics gloves. Eye protection is critical when working near compressed springs.
  • Remove any loose items from the interior and trunk to avoid shifting weight.
  • Let the vehicle cool completely if it has been driven; hot components can cause burns.
  • Apply penetrating oil to any bolts that look corroded, especially the sway bar link nuts and lower control arm bolts. Allow the oil to soak for at least 10 minutes.

Step 1: Lifting the Vehicle

Safe lifting is non-negotiable. An improperly supported car can cause serious injury or damage.

  1. Position the jack under the front center jacking point (consult your owner’s manual for exact location).
  2. Pump the jack until the front wheels are just off the ground, then place jack stands under the designated lift points on the frame rails.
  3. Lower the vehicle gently onto the stands and shake it to ensure stability.
  4. Repeat the process for the rear. It is often easiest to raise both ends at the same time, but you can work one end first if preferred.

For additional safety, leave the wheels under the car as a backup barrier.

Step 2: Removing the Front Suspension Components

With the car safely lifted, begin with the front suspension removal.

2.1 Remove the Front Wheels

  • Loosen the lug nuts with a breaker bar while the wheel is still on the ground, then lift and remove them.
  • Set the wheels aside flat, out of the work area.
  • Locate the sway bar end link connecting the sway bar to the strut.
  • Use a wrench to hold the link stud while loosening the nut. A hex key may be needed on some variants.
  • Remove the link and set it aside. If the link is stubborn, apply more penetrating oil.

2.3 Unbolt the Lower Control Arm from the Strut

  • Support the lower control arm with a jack or use a jack stand to prevent it from dropping.
  • Remove the two bolts securing the control arm to the strut. Note the washer orientation for reassembly.
  • Once free, carefully lower the control arm slightly to allow clearance.

2.4 Remove the Strut Assembly

  • Support the strut from below.
  • Remove the top strut mount bolts located under the hood (three or four bolts, typically 13 mm).
  • Slide the strut assembly out from the wheel well. Be careful not to damage the CV axle boot or brake lines.

Repeat for the opposite side.

For a detailed factory removal procedure, you can reference the Mercedes-Benz technical information portal (note: official microfiche or repair manuals provide torque specs).

Step 3: Installing the Dinan Front Suspension

Now install the Dinan components. Safety is paramount when working with springs.

3.1 Compress and Transfer Springs

  • Place the removed strut assembly in a spring compressor.
  • Compress the factory spring evenly until it is free from the strut seat.
  • Remove the top mount and spring, then decompress the factory spring.
  • Repeat the process with the Dinan spring: compress it, install it onto the Dinan strut, add the top mount (use the original or Dinan-supplied mount), and tighten the center nut to the manufacturer’s specification (commonly 60 Nm).

3.2 Install the Dinan Strut Assembly

  • Guide the assembled strut up into the wheel well, aligning the top mount studs with the holes in the chassis.
  • Hand-tighten the top mount bolts.
  • Lift the lower control arm back into position and install the two bolts. Torque them to factory spec (typically 140 Nm for the two large bolts).
  • Reconnect the sway bar link and torque the nut to around 40 Nm.

3.3 Reinstall the Front Wheels

  • Place the wheel on the hub and hand-tighten the lug nuts.
  • Lower the car to the ground before final torquing to 130 Nm (use a star pattern).

Step 4: Removing the Rear Suspension Components

Move to the rear of the vehicle. The procedure is similar but with some differences.

4.1 Remove the Rear Wheels

  • As with the front, loosen lug nuts first, then lift and remove wheels.

4.2 Unbolt the Lower Control Arm from the Rear Strut

  • The rear suspension uses a multi-link setup. Locate the lower control arm attached to the strut.
  • Remove the bolt(s) holding the arm to the strut. You may need to support the arm to avoid stretching the bushings.

4.3 Remove the Rear Strut Assembly

  • Access the top strut mount inside the cargo area (remove any trim panels covering the mounts).
  • Remove the top mount bolts (two nuts, typically 18 mm).
  • Carefully lower the strut assembly out through the wheel well. Note: The rear springs are separate from the strut on some models; you may need to compress the spring before removal. Ensure the spring is not under tension when disconnecting.

Step 5: Installing the Dinan Rear Suspension

Similar to the front, but note the orientation differences.

5.1 Assemble the Rear Strut/Spring

  • If your Dinan kit includes separate springs, compress the Dinan spring using spring compressors.
  • Install the spring onto the Dinan rear strut, then add the upper spring seat and top mount.
  • Torque the center nut to manufacturer specification (often 70 Nm).

5.2 Install the Rear Strut Assembly

  • Insert the assembly into the wheel well and align the top mount studs with the holes in the chassis.
  • Secure the top mount bolts and torque to spec (typically 20 Nm).
  • Reattach the lower control arm and torque the bolt (around 140 Nm).

5.3 Reinstall the Rear Wheels

  • Place the wheels on, hand-tighten lug nuts, lower the car, then torque to 130 Nm.

Step 6: Finalizing the Installation

After installing all four corners, it’s time to double-check everything.

  • Go over every bolt and nut with the torque wrench. Pay special attention to the sway bar link nuts, control arm bolts, and top mount fasteners.
  • Inspect the brake lines, ABS sensors, and wiring for any pinching or rubbing.
  • Reinstall any trim pieces removed from the trunk or under-hood areas.
  • Lower the vehicle completely and bounce the suspension a few times to settle the components.
  • Check ride height: the car should sit evenly side to side. If not, the spring seats may need adjustment.

Test Drive and Post-Installation Checks

A thorough test drive confirms the installation was successful.

  • Drive slowly over a speed bump or rough road to listen for clunks or noises. A slight settling sound is normal; metallic knocking indicates a loose component.
  • Find an empty parking lot and perform a few tight figure-eights to check for binding or rubbing.
  • Test the brakes at low speed to ensure no interference.
  • After 100 miles, recheck all torque values. Springs can settle and cause bolts to loosen slightly.
  • Consider getting a professional wheel alignment. Dinan recommends alignment to factory specs, but a custom alignment can further optimize handling. Typical camber settings for the CLA45 AMG range from -1.0° to -1.5° front and -1.5° to -2.0° rear for street/occasional track use.

For alignment specifications and additional tuning advice, forums like Mercedes Forum or BenzWorld provide community-vetted data.

Common Pitfalls and Tips

  • Spring orientation: Dinan springs may have a specific orientation. Look for a helper spring or end coil position.
  • Torque specs: Always use a torque wrench. Under- or over-torquing can cause failure or noise.
  • Patience with rusty bolts: Soak in penetrating oil and apply heat (if safe) before forcing a bolt.
  • Double-check hardware: The Dinan kit may include new nuts or bolts. Use them as specified.
  • Reuse or replace: It’s advisable to replace strut mounts and bump stops if they show wear.

Conclusion

The Dinan Suspension Upgrade is one of the most rewarding modifications you can make to a Mercedes-Benz CLA45 AMG. By following this step-by-step guide, you can confidently install the kit yourself, saving labor costs and gaining a deeper understanding of your vehicle’s suspension geometry. The result is a car that corners with authority, rides comfortably on highways, and inspires confidence at every turn. For further reading on Dinan’s engineering philosophy, visit the Dinan about page. Always remember: safety comes first, and when in doubt, consult a professional.