Ferrari 360 Crankshaft Spacer Tool 3D Printed

 

One of the important jobs that need to be done periodically on the Ferrari 360 is a "belt service". The timing belts and the rest need to be changed every three to five years. 

Once the crankshaft pulley is removed, a spacer needs to be inserted, and the bolt replaced so that the engine can be hand turned to move it to top dead center, and also, after the belts are installed, the engine needs to be turned over several times to seat the belts and checked for tension.

Here's the bare crankshaft after the pulley has been removed.

I found it cumbersome to turn the crankshaft using the large 36mm socket required as the crankshaft pulley bolt has a short head. With the large socket and heavy ratchet, it's really a two handed job to turn over the engine.

Instead of using a short piece of pipe or washers to fill in the pulley space, I decided to make an adjustment that would allow the spacer to fit snugly over the crankshaft and lock into place using the key. To turn the crankshaft, I dropped the requirement to use the bolt and instead, formed the spacer so it would fit into a twelve point 1-1/2" socket. Not only does this remove the step for replacing the bolt, and removing it later, it also gives the socket a lot more "meat" to grab so that the socket hangs on the crankshaft securely. 

Here's the design of the spacer, which is really an insert for the socket.

One of the challenges in this design is to allow enough room for the key. The largest socket in my tool kit is a 1-1/2" twelve point Craftsman socket which is just barely big enough to allow room for the key and plenty of plastic around it so that it can take the torque required to turn over the engine. I did this by offsetting the center for the twelve point insert just enough so that the key is completely enclosed by several layers of plastic as can be seen below. 

Here's the insert sitting next to the 1-1/2" twelve point Craftsman socket. The socket can be purchased on Amazon for less than $10 individually. It's a common socket to be included with a set so may already be in your toolbox.

Here's the spacer inserted onto the crankshaft. Note how it moves the pivot point for the ratchet inward at least two inches. 

Here's the finished assembly with the insert on the crankshaft and the socket and ratchet hanging nicely from it. This unit can take a lot of torque, a lot more than is required for turning over the engine.

I used Amazon Basic black PLA printed with 0.2mm height, 0.4mm nozzle, 80% infill, 8 perimeters, and 8 layers on the top and bottom.

Update: New version created that's more robust and holds place in the socket better.

This tool can be downloaded for free here:

https://www.printables.com/model/554745-ferrari-360-crankshaft-spacer