Pillowball vs Rubber Top Mounts: Noise, Feel and Camber Plates
Pillowball top mounts replace the factory rubber bushing with a spherical bearing, which sharpens steering and often adds camber adjustment. The price is more noise and vibration in the cabin. Rubber mounts stay quieter and softer but let the strut shift a little under load.
Most people never think about the top mount until they install a coilover kit and hear a new clunk over a driveway lip. Or until the alignment shop says it cannot get more camber. Both problems start at the same small part. Here is what it does, how the two types differ, and how to pick.
What a Top Mount Does
The top mount, also called the upper mount or strut mount, connects the top of the coilover to the body. Every bump the wheel takes passes through it. It also carries the weight of that corner of the car through the spring.
On a MacPherson strut front end, the strut turns with the steering. So the mount has to let the strut rotate while it holds it in place. On many rears, the damper does not steer, so the mount does not need to rotate.
The top mount bolts to the body, so it is sprung mass. Swapping it does not change unsprung weight. Unsprung weight is the wheel, tire, hub, brakes and knuckle, plus part of the arms, damper and spring. If you want less of that, look at wheels and brakes, not mounts.
Rubber Top Mounts: Quiet and Compliant
A factory top mount uses rubber between the strut and the body. The rubber soaks up small, sharp inputs before they reach the cabin. That is why most road cars ride quietly over expansion joints and broken pavement.
The trade-off is movement. TEIN explains that a rubber bush adds compliance under load. In plain terms, the top of the strut can shift a little when you corner hard or hit the brakes. TEIN says that shift changes the alignment under load and costs some tire grip.
For a daily driver, that small movement is a fair price for a quiet cabin. Some coilover kits reuse the factory mount. Check your kit's parts list to see which you have.
Pillowball Top Mounts: Direct and Adjustable
Pillowball top mounts swap the rubber for a spherical bearing, a metal ball held in a race. The ball lets the strut pivot and rotate, but it does not squish. Ksport describes the spherical-joint design as a stiffer, less compliant connection between body and suspension.
TEIN says its pillow ball upper mount eliminates load input compliance and gives sharper, more direct steering feel. TEIN adds that it reduces alignment change to improve tire grip. Ksport says steering feel and response improve with pillowball upper mounts.
Most pillowball mounts also bring adjustment. The plate has slots, so you can move the top of the strut to set camber. Some also move fore and aft for caster. Ksport lists a Standard model with camber adjustment only and an Advanced model with camber and caster.
Noise, Feel and Who Notices
Here is the catch. A bearing that does not flex also does not filter. Noise and vibration that rubber would absorb now reach the body.
The industry says so openly. HP Academy says solid bearing mounts bring a lot more noise, vibration and harshness. It calls them a good call for the track but sometimes unpleasant on the road. Ksport says it puts a rubberized coating over the metal on its Kontrol Pro pillowballs to help reduce noise. That tells you noise is the known trade-off.
Who notices depends on the car and the roads. Think about the whole performance suspension package, not just one part. A track car with a stripped interior will not care. A quiet sedan on a rough commute will. If you drive mostly on the street, ask whether the mount for your kit is a bare bearing or an isolated one.
New noises after an install are not always the mounts. Loose end links, a top nut that is not torqued, or a spring that is not seated all make noise too. Our guide to coilover noise walks through how to find the source. Note also that BC Racing's series pages say noise from its track-oriented kits is not covered by warranty, so read the terms for your series.
Camber Plates: How the Adjustment Works
A camber plate is a top mount with slots. Loosen the bolts, slide the upper end of the strut inboard for more negative camber or outboard for less, and lock it down. On a MacPherson strut front, it is one of the main ways to add camber past the factory range. Camber bolts at the knuckle are another.
TEIN notes that on its pillow ball mount, camber is adjustable on MacPherson strut models, front only. The rear of many cars sets camber through the arms instead. Our guide to suspension geometry and alignment explains how camber, caster and toe work together.
Any change at the plate needs an alignment. Ride height changes also alter camber and toe, so set ride height first, then camber, then have the shop set toe. Lock every locking collar before the car goes on the rack.
Which Kits Ship With What
Mount type and plate type vary by brand and by car, so read the listing for yours. The same brand can use different mounts on different chassis. Here is what our catalogue and the brands show.
BC Racing. BC Racing lists front camber plates as standard on applicable BR Series kits, with rear camber plates available for applicable kits. Some of our BC Racing titles say so outright, such as the 2002 to 2007 Subaru Impreza WRX AWD kit (Rear Camber Plates Ordered Separately). We also list rear camber plates for BC Racing coilovers for certain models. Swift Springs SPEC-R springs are an upgrade option on most BC Racing fitments.
Fortune Auto. We list a 2009 to 2014 Honda Fit kit with PRO Camber Plates (GE), separate from the standard Fit listing.
Öhlins. Öhlins lists adjustable front strut mounts sold individually, such as the E46 BMW 3 Series front strut mount, left. One Öhlins E9X 3 Series listing ships without upper mounts, and its title says so.
Whiteline. Whiteline lists a front strut mount pair with camber and caster adjustment (KCA476). Confirm fitment on the product page.
KW, TEIN and Bilstein each handle mounts their own way by kit and car. Always check the parts list, or call 1-800-460-9106 with your VIN and we will tell you what comes in the box.
Living With Pillowball Top Mounts
A pillowball mount needs a little attention. At each service, check the top nut torque and the plate bolts. With the car on the ground, have someone rock the steering while you listen at the strut tops. A knock that was not there before means something has loosened or worn.
Treat the bearing like any other wear part. If a knock comes back after you have checked every bolt, the bearing may have play, and the mount may need service or replacement. Ask the brand or us before you take one apart.
Keep the plates clean, especially in winter, and keep the camber bolts tight. If you move the plates, mark the old position first so you can go back. Our guide to suspension bushings and mounts covers the wider trade-off between rubber, polyurethane and metal joints across the car.
Frequently Asked Questions
Are pillowball top mounts noisy?
They pass more noise and vibration than rubber mounts, because the bearing does not flex. How much you notice depends on the car, the roads and the mount design. Some pillowballs use a rubberized coating to cut noise.
Are pillowball mounts good for a daily driver?
They can be, if you accept some extra noise. In return you get sharper steering feel and camber adjustment. If a quiet cabin matters most, stay with a rubber-isolated mount.
Do I need camber plates with my coilovers?
Not always. On a mild drop, the factory adjustment may be enough. On a bigger drop, or for track camber, a camber plate on a strut front is often the fix. BC Racing lists front camber plates as standard on applicable BR Series kits.
What is the difference between a camber plate and a pillowball mount?
A pillowball mount describes the bearing inside. A camber plate describes the slotted plate that lets you move the upper end of the strut. Many parts are both: a slotted plate with a spherical bearing in the middle.
Do top mounts affect ride quality?
Yes, mostly in noise and small, sharp impacts. Rubber filters them, a bearing passes them on. Spring rate and damping still decide most of the ride. Our guide on how coilovers affect ride quality covers the rest.
Can I switch from pillowball top mounts back to rubber?
Often, yes, but it depends on the kit. Some coilovers are built around their own mount and will not accept the factory part. Others reuse the factory mount on some cars. Ask us before you buy parts, and give us your VIN and kit details.
Can I reuse my factory top mounts with coilovers?
Sometimes. BC Racing kits include camber-adjustable upper mounts on most applications. Other brands reuse the factory upper mount on some cars, and the listing or parts list tells you which. If yours is reused, inspect it first. Cracked rubber, a rough bearing or a knock means replace it while the corner is apart. Recovering a factory mount means taking apart a strut with a compressed spring, so use a proper spring compressor or let a shop do it. Our coilover install guide covers the job step by step.
Do I need an alignment after adjusting camber plates?
Yes. Any camber change affects how the tire meets the road, and toe needs checking too. Set ride height first, then camber, then have the shop set toe.
Not Sure Which Mount Suits Your Build?
Tell us how you use the car and how much noise you will put up with. That usually settles rubber versus pillowball in a minute.
Call 1-800-460-9106 with your VIN. We will check what mounts come with your coilover kit and whether camber plates make sense for your car. Free shipping across Canada on most kits.
1-800-460-9106Browse Kits by Your Car