Alignment Part 2: Camber Plates, Bolts, and Arms

Last time in our series on alignments, we talked about the basics: camber, toe, and why you may want a performance alignment. To get that perfect alignment though, you may need to add a few parts to your car.

All cars will let you adjust toe, but not all have camber adjustment from the factory. And depending on your goals, you may not have enough adjustment to reach the alignment numbers you need with the factory parts. That’s where camber bolts, camber plates, and adjustable control arms come in.

Camber bolts are an inexpensive way to add some negative camber to a strut suspension. These area bolt with a smaller diameter and a lobe for the lower strut to hub mount, allowing the hub and wheel to be titled inwards.

A common thought is that camber bolts can slip. This is less likely with the right bolt installed correctly, but lobed camber bolts are not often used in high load/grip motorsports applications. You will instead see slotted lower mounts and camber “chips” or shims, which effectively lock in the bolt.

Camber bolts have their place and can be useful. As with any suspension modification, care should be taken to ensure proper installation and fitment with all other components including wheel and tire clearance. Downsizing a bolt too far or poor installation will cause problems.

Another way to add camber to a strut suspension is with camber plates. Mounted at the top of the strut where it connects to the chassis, these allow you to tilt the whole strut inwards and can add a large amount of camber. Adding negative camber from the upper mount (with camber plates) as opposed to the lower mount does have implications that will be discussed in a future article.

Camber plates are usually an all-metal design. Rubber factory mounts prioritize noise, vibration, and harshness (NVH) isolation with a less direct connection.

These RCE SSR 3-way coilovers use both a camber plate and a slotted lower mount for camber adjustment. The plates use a recessed design which adds bump travel for a given ride height. Most flat camber plates will raise the car slightly.

Strut, multilink, and wishbone-based suspension designs can use length-adjustable arms or arms with eccentric bolts to adjust camber and toe. The goal is to adjust the length of the arm longer or shorter to adjust wheel hub position or angle.

Most aftermarket control arms will use a threaded rod end or ball joint that can be locked down once set. This usually replaces a factory rubber bushing with a spherical bearing, which may add NVH (though the change can be small).

Adjustable rear lower control arms (1), rear toe arms (2), and front lower control arms (3) for Subaru BRZ and Toyota GR86. Setting camber with one arm will impact toe as well, so adjusting at more than one location is required. A skilled technician is needed to dial everything in properly.

Improperly designed or adjusted suspension arms can break, which is more common than you might think. Less weight is good, but strength is more important. Shaving off too much weight or compromising strength for more adjustment is a recipe for disaster.

Adequate articulation for the arm is also crucial. If the pivot point is restricted in a way that it shouldn’t be, such as with a sticky bushing or a spherical bearing without enough range of motion, you’re severely impacting your handling, ride, and risking a failure.