Installing a new clutch while you swap a tired old engine out of the car is a good idea. It’s one of those “while you’re in there,” things that make a job more comprehensive and it tends to create a better finished product.
For the 2.5 swap in the 2006 TT5 MX-5, we knew it was going to be driven primarily on the street with some track use from time to time. Thinking back to our feature story on how to choose a clutch, we sourced one from Advanced Clutch Technology for a clutch kit and a lighter-than-stock flywheel.
Because the car is going to be a daily driver, we went with a full-circumference disc with organic friction material and a sprung hub. If you don’t know what any of that means, you can check out the video on YouTube, which is a step-by-step tour through the Advanced Clutch Technology factory in Lancaster, Calif., detailing how clutches are made.
The flywheel itself is only marginally lighter than stock to improve street drivability and the pressure plate was the standard ACT model, the only one offered for the 2006 MX-5. That seemed like it would be strong enough to hold the increased torque of the 2.5 liter four.
The kit also came with an alignment tool, a release and pilot bearing and the snazzy purple grease for the splines, the release bearing, and the throw-out fork tips. It had everything needed for the swap.
Before we get into the specifics and the in-depth photos, there are a couple of things to note. First, unlike previous generation Miatas, the pilot bearing is different on one end than it is on the other, so there is a right way and a wrong way to install it. For the NC chassis, you install the bearing with the lip toward the transmission. From the information we found, the lip is to seal the grease in the needle bearings. There is a factory special tool for tapping it into place, but a 14 mm deep socket is a good substitute.
Second, the flywheel and pressure plate bolts get torqued incrementally. In other words, you don’t torque the flywheel bolts to 82 foot-pounds on the first round. You first torque them to 40, then 60 and then the final 82. There’s a similar sequence for the pressure plate bolts, which ACT supplies in the kit.
You’ll also need a tool for locking the flywheel in place, which is something that does not come in the ACT kit. We sourced one from Flying Miata. As with everything, patience and attention to detail are paramount. Here’s how the job unfolded.
When the pressure plate is torqued, you should be able to push in and pull out the alignment tool using just your fingers. If it binds, you need to disassemble, figure out why it binds and then reassemble.