Stopping the Clutch

The BMW Z3 was built to a budget. All cars are, but the Z3 in particular has a bit of a "parts-bin special" reputation. In the early 90's, there were very few convertibles even being sold. But then Mazda hit a home run with the Miata, and BMW decided to test the waters with a brand new model - the Z3, introduced in 1996. To save development and parts costs, many Z3 parts were recycled from the BMW 3-series coupes and sedans, and the interior in particular was rather cheaply made.

It's obvious that the original spec for the Z3 included a stop behind the clutch pedal, to limit the pedal travel. Every Z3 convertible and coupe has a threaded hole in the floorboard, behind the clutch:

Incidentally, that's the Nebo Larry work light I posted about earlier, hanging from the brake pedal by its magnetic clip, illuminating the threaded hole.

My guess is that the decision to omit the clutch stop was made late in the design cycle. It was easy to just not put the part there, but harder to change the floorpan design to get rid of the hole. That made it possible for the aftermarket to leap into action and provide a stop. I chose the UUC Motorworks Ultimate Clutch Stop, which has a big rubber face that will be quiet in operation and provide a little cushioning against shock when the pedal hits the stop:

Installation is super simple - just thread the lock nut onto the shaft as far as it will go, then slip on the washer and thread the stop into the hole in the floorpan. Once it's in the right place, run the lock nut back down until it is snug, and tighten it with a 17mm wrench to lock the stop in position.

Since it was easy to do, I used my portable car lift to raise the tires about an inch off the ground. That way, it was easy to tell exactly when the clutch was engaging. I just looked out the open driver's door back at the rear tire to see if it was starting to turn. I adjusted it so that there's only about a half-inch of travel beyond the point where the clutch engages. Here's what it looks like installed.

The test drive told me that I should have bought one of these long ago. It's just a reflex to push the clutch as far as it will go. Having a positive stop means I'm no longer stretching to hit the floor, and it makes shifting a bit faster as well. Worth doing!