Heidi Hetzer Driving Tour - Update #10


Watchmaker, Watchmaker, make me a...speedometer

The trip to the watchmaker went better than planned. The issue with both speedometers in Heidi's possession was the cable input gear. That's where the square end of the speedometer cable is inserted to drive the internals. Eighty years of use had worn the size of the formerly square receptacle past the point the cable would remain engaged. 


So instead of driving the internals, the cable would slip. The watchmaker's solution was simple. Instead of attempting to replace the speedometer's internal drive gear, he chose to enlarge and square up the size of the now nearly round hole. The cable tip was subsequently enlarged using silver solder, then hand fitted to the speedometer.
OLD #7
The connecting rod and all other parts were hand delivered by courier to the shop. The first step was to remove the old piston and rod. Based on the update, it took an enormous amount of time to "massage" the piston out of the cylinder without damaging it or the crankshaft. At one point, it looked impossible. If that were to occur, the head would need to be removed. No one planned for that so the parts did not include a new head gasket. But after almost an hour it was out and in hand.

Step number two was to measure the bearing clearance. It too went without any issue. By reusing the .006 shims (seen LL in the photo) bearing clearance was brought within the tolerances of a new engine. The wrist pin was pressed back in and Heidi began the process of reassembly. 

Again, it took almost an hour, but in her own words, "after compressing the rings by hand, it made a gentle "schlupp" sound and the piston slid into the number seven cylinder". The connecting rod was torqued and smiles were beginning to emerge. The focus then turned to the oil pan. All of the remaining metal particles were carefully removed, the pan rinsed then readied for installation with new gaskets.
"By this time it was 22:00 (10 PM) and the shop foreman begged to go home."

The belief is the remaining work will be done in the morning. After adding 10 quarts of fresh oil, everyone will be eager to hear the straight eight start and run like a...well, watch. Providing all goes well, the speedometer and cable will also be reinstalled, a test drive will take place and the trio (Heidi, Hudo and Patrik) will again be on their way. In closing, the courier also brought updated visas for Heidi and Patrik, Patrik is getting past the flu, and the weather forecast is perfect for departure.

Until next time, Garagistry out.