Introduction to Delrin Suspension Bushings

Upgrading your car’s suspension bushings to Delrin is one of the most transformative modifications you can make for handling precision and steering feel. Unlike factory rubber bushings that flex under load, Delrin (acetal homopolymer) offers near-zero compliance, giving you immediate feedback from the road. This is especially valuable on track cars, autocross machines, or daily drivers where driver confidence matters.

Delrin bushings are machined from a rigid, self-lubricating plastic that resists moisture, chemicals, and temperature extremes. They do not squeak as much as polyurethane alternatives if properly lubricated, and they last significantly longer than rubber. However, they also transmit more road noise and vibration into the cabin. If you are prepared for that trade-off, installing Delrin bushings is a rewarding weekend project that will sharpen turn-in response, eliminate slop, and give you a more connected driving experience.

This guide provides a step-by-step walkthrough for replacing suspension bushings with Delrin units, from tool selection through final test drive. Always consult your vehicle’s service manual for specific torque values and procedures, as variations exist between makes and models.

Tools and Materials Needed

Gathering the right tools before you start prevents mid-project frustration. Beyond standard hand tools, a bushing press or improvised press setup is highly recommended for Delrin bushings, because they are harder than rubber and require controlled force to seat correctly.

  • Delrin bushing set – Ensure the kit is designed for your specific vehicle model and suspension arms (control arms, trailing arms, sway bars, etc.).
  • Socket set and wrenches – Including deep sockets for suspension bolts. Metric and SAE depending on your car.
  • Bushing removal and installation tools – A ball joint press, C-clamp press, or hydraulic press is ideal. A bench vise with appropriately sized sockets can also work.
  • Silicone-based lubricant – Essential for installation and long-term noise prevention. Do not use petroleum-based lubes as they degrade Delrin.
  • Jack and jack stands (at least two) – Never work under a car supported only by a jack. Use certified jack stands rated for your vehicle’s weight.
  • Rubber mallet – For gentle persuasion. Avoid metal hammers that can damage the bushing surface.
  • Protective gloves and safety glasses – Pressing operations can cause shrapnel if a tool slips.
  • PB Blaster or penetrating oil – For loosening rusted bolts and old, seized bushings.
  • Torque wrench (ft-lb and in-lb if needed) – Critical for reassembly to avoid overstressing components.
  • Wire brush and rag – To clean mounting bores before installation.

Preparation Steps

Safety and Lifting

Park your car on a level concrete surface and engage the parking brake. Loosen the lug nuts on the wheels you will be removing before lifting the car. Using a floor jack, lift the vehicle at the designated chassis jacking points, then place jack stands under the frame rails or subframe. Never rely on a hydraulic jack alone. Lower the car onto the stands and give it a firm shake to verify stability before going underneath.

Accessing the Suspension Components

Remove the wheels and set them aside. Depending on which bushings you are replacing (control arms, sway bar links, trailing arms), you may need to disconnect sway bar end links, unbolt shock absorbers, or separate ball joints. Take photos before disassembly to aid reassembly. Support the lower control arm with a jack stand if you need to remove the spring or strut assembly.

Identify each bushing that needs replacement. Original rubber bushings often crack, bulge, or become soft with age. If they are still intact but have high mileage, it is still worth upgrading for handling improvements.

Removing Old Bushings

Removing factory rubber bushings can be the most labor-intensive step. Rubber bushings are typically bonded to a metal outer sleeve that is pressed into the suspension arm. Several methods work:

  • Press method – Use a ball joint press or hydraulic press with appropriately sized cups and adapters. Place the arm so the bushing is supported around its outer edge, then press the bushing out. Heat (from a propane torch) applied to the surrounding metal can help loosen stubborn bushings, but be careful not to damage the arm.
  • Drill and chisel method – If a press is unavailable, drill multiple holes through the rubber to weaken it, then use a hammer and chisel to collapse the inner sleeve. Remove the outer shell with a hacksaw blade or cut-off wheel (take care not to cut into the arm).
  • Heat and twist – Apply heat to the outer sleeve and use a large socket and ratchet to twist and break the bond. This works best on sway bar bushings.

Once the old bushing is out, thoroughly clean the mounting bore with a wire brush and brake cleaner. Remove any rust, burrs, or leftover rubber pieces. The bore must be smooth for the Delrin bushing to slide in without binding.

Installing Delrin Bushings

Lubrication and Alignment

Apply a generous coat of silicone-based lubricant to the outside of the Delrin bushing and the inside of the mounting bore. Do not use grease that contains molybdenum disulfide or lithium, as those can react with the plastic. Silicone grease stays slippery and does not degrade Delrin.

Position the bushing at the mouth of the bore, making sure it is square. Delrin bushings often have a flange on one side; ensure the flange sits flush against the arm surface when fully installed. Pressing the bushing in crooked can damage both the bushing and the suspension component.

Pressing the Bushing

Use a press or C-clamp with a socket slightly smaller than the bushing OD to push it into place. Apply steady, even pressure. If you feel resistance, stop and check alignment. A rubber mallet can be used to gently tap the bushing as it enters, but only if it is already partially seated. For arms that are difficult to access, a bench vise with appropriate spacers works well.

Press until the bushing is fully seated – the flange should contact the arm surface, or the bushing should be flush with the bore on both sides (check your kit instructions). Over-pressing can deform the bushing or crack the arm. If the bushing is a tight fit, chilling the Delrin in a freezer for an hour can slightly shrink it and ease installation.

Installing Inner Sleeves (If Applicable)

Some Delrin bushing kits include a metal inner sleeve that the bolt passes through. After the Delrin body is pressed in, insert the metal sleeve. It should slide through easily; if it is tight, gently tap it with a rubber mallet. Do not force it, as this could compress the bushing and cause binding.

Reassembly and Torque Specifications

Reattach the suspension components in reverse order of disassembly. Use new hardware where supplied, and apply thread locker (blue Loctite) to bolts that mount into aluminum threads or critical fasteners. Tighten all bolts to the manufacturer’s specifications. Do not rely on “feel” – a torque wrench is essential for suspension bolts. Under-torquing can cause loosening, while over-torquing can strip threads or distort the bushing.

Important: For control arm bushings that are mounted with the vehicle’s weight on the ground (i.e., the bushing rotates as the arm moves), tighten the pivot bolts only after the vehicle is lowered to ride height. If you tighten them with the suspension hanging, the bushing will be twisted during normal operation, leading to premature failure and harshness. Raise the suspension to simulated ride height with a jack before final torque, or use the “lift-and-tighten” method.

Final Checks and Test Drive

After all fasteners are torqued, check that no suspension components are binding. Rotate the steering wheel lock-to-lock and verify the wheels move freely without obstruction. Reinstall the wheels, lower the vehicle to the ground, and torque the lug nuts to spec in a star pattern.

Go for an initial test drive on a quiet road. With Delrin bushings, you will notice:

  • Sharper steering response and reduced on-center vagueness
  • More road feel transmitted through the steering wheel and chassis
  • Reduced body roll and squat under hard acceleration/braking
  • Increased noise (suspension clunks from road imperfections, higher-frequency vibration). This is normal and is the price of performance.

Drive aggressively for a few miles to allow the bushings to settle. If you hear persistent squeaking, the bushings may be dry. Remove, re-lubricate with silicone grease, and reinstall. Delrin does not absorb lubricant, so it must be applied externally.

Long-Term Maintenance and Considerations

Benefits of Delrin Bushings

  • Zero deflection under cornering loads – improves alignment stability
  • Very durable – resists cracking, dry rot, and oil degradation
  • Low friction – less stiction than polyurethane
  • Consistent performance across temperature ranges (‑40°F to 180°F)

Drawbacks to Know Before You Install

  • Harshness – Delrin transmits road imperfections directly into the chassis
  • Noise – expect increased interior noise from bumps and vibrations
  • Difficult installation – requires press or heavy tools; not a bolt-in for most arms
  • Not street-friendly for daily commuters who prioritize comfort
“If you are building a dedicated track car or autocross machine, Delrin is often the best choice. For a dual-purpose car, consider a hybrid setup using Delrin only in critical locations (like the front lower control arms) and rubber or polyurethane elsewhere.”

Additional Tips for a Successful Installation

  • Work in a clean environment to prevent grit from scratching the bushing surface.
  • If you are removing control arms entirely, consider replacing any worn ball joints or tie rod ends at the same time.
  • Use anti-seize on fastener threads, especially if your car sees winter salt.
  • After 500 miles, recheck torque on all suspension bolts – they can settle as the bushings compress slightly.
  • If a bushing becomes loose in its bore, remove it and apply a thin layer of epoxy or Loctite retaining compound (e.g., Loctite 638) to the outside before pressing. This is rarely needed but can solve fitment issues.

For additional technical details, consult DuPont’s Delrin material properties page to understand its mechanical limits. For vehicle-specific bushing compatibility, reference Energy Suspension’s catalog (which also sells Delrin in some applications). A comprehensive guide on suspension bushing types can be found on CarThrottle’s bushing comparison article. Always cross-reference your factory service manual for torque specs and procedures.

Installing Delrin bushings is a mechanical commitment that pays off with razor-sharp handling. Take your time, use the right tools, and you will transform your car’s suspension character for years to come.