Any Ferrari Meister out there that can tell me the proper procedure to shim the brake calipers on a 328? I've already done it but I don't know if I did it correctly. On the rears I shimmed so that the top of the caliper holder bracket was equi-distant from the brake disc surfaces (as close as I could get them using a feeler guage). Then I shimmed the bottom of the caliper holder bracket on the outside of the brake disc as close as possible (with the combination of shims I had) to match the gap at the top of the bracket to the outside surface of the disc. Haven't touched the fronts yet. What's the purpose of this? Even pad wear? Maximum contact area/pressure? Vibration reduction? All of the above?
I kinda did the same recently to mine. I just eyeballed it though, and had shims left over from when the old pads were installed.
I have replaced the rear pads on my 328 and did just that. I would also be interested in knowing if this is the right procedure. Since I will soon replace the front ones, would that be the same? Or is there a way to replace the front pads without removing the shims?
From a Technote I did in Prancing Horse a while back... Caliper installation- The calipers are now ready to install. Place the first caliper onto the mounting point of the hub or spindle and install the two mounting bolts and lockwashers, tightening the bolts snug but not torqued. Using feeler gauges, measure the distance between the caliper casting at a point nearest the rotor, to the rotor itself (Fig-28). If not identical, the caliper must be shimmed. Shims are installed between the caliper mounting face and mounting bracket, using the attachment bolts to secure them. Shims are available in a variety of thicknesses (Fig-29), or can be made from shim stock as required. Example: Inboard clearance .025; Outboard .127. Difference .102 divided by 2 equals .051 shim required between caliper and mount. Use the same thickness shim on both the upper and lower bolt location. Repeat for other calipers and mark shims as to locations.
Thanks for the info. and photo Bill. I shimmed the caliper holding bracket with the caliper off as opposed to shimming for the caliper itself. Is it better/more important to shim the caliper distance to the disc rather than the bracket? What about the brake disc.... does it need to be torqued down to the hub? I bought special short screws for this to bolt it down to specs. with no wheel on. It would seem you need to have a brake disc that has very little run-out or that might mess up the measurements too. I see in the photo that it's not a 328 you're showing or at least not stock brakes and hubs. Not sure if that would make a difference in procedure.
The procedure is the same for ANY caliper install, centralising and aligning the caliper is key for noise and vibration. If your rotor has runout that will affect it and should be replaced/machined anyway. Important to keep the caliper parallel with the hub/rotor or you will have severe vibration until the pads wear significantly. Shown pic is a BB or TR.
