11/3/2026: Speedometer and cooling system work.
The image at the left is the Classic Instruments speed sensor. It is comprised of two parts: the SN16 signal generator and the SN17 adaptor. The adaptor is at the distal end from the wires and it interfaces with the Ford Tremec TKX transmission. The signal generator produces 16,000 pulses per mile. The adaptor has a shaft (the black thing protruding from the adaptor) that, when coupled to the signal generator (the adapter and generator screw together) turns a shaft in the signal generator. I tested the system by hooking up the speedometer gauge to the generator assembly and turned the black shaft using my drill at low speed. The speedometer responded appropriately! The actual calibration will be done when in the transmission and on the first drive.
.The four photos above show the sensor placement. From left to right:
1. The SN17G18 gear and retaining clip. This gear slides on the end of the adaptor (SN17) and meshes with the worm gear in the transmission when inserted.
2. The assembly, bottom to top: SN16, SN17, SN17G18. The bottom of the assemble attached to the wiring harness shown in the photo in the first paragraph.
3.The insertion point in the Tremec TKX transmission. I was a bit disconcerted at first because the Tremec diagram seemed to indicate a different port for the sensor. The Torx bolt holding what I thought was a cap on the insertion spot was stripped and I tried several ways to get it loose. The problem, for me, was that the Tremec diagram had the port label exactly on top of the port (see the diagram below; #4); I thought that the port was the feature immediately above the #4 in the diagram. Once I realized my mistake, the cap on the correct port was easily removed.
4. The sensor in place in the transmission.
A photo of the left hand side of the Tremec TKX. The port for the mechanical speed sensor is labeled as #4 but I thought it referred to the feature just above it on the photo. My mistake! The label is exactly on top of the port.
There is a lot of discussion of the forums regarding cooling tubes. It’s generally accepted that the corrugated tubes from Factory Five should not be used: fatigue cracking, diffucilty fitting and aesthetics are the primary reasons. Personally, I sort of like the corrugated steel look but the longevity issues bothered me. As such, I decided to go old school and use hose from NAPA for a Mustang 5.0 engine (NAPA 7865) for the upper tube assembly. The hose needed to be cut for the filler ‘T’ to be used in-line. For the T, I purchased a Fluidyne neck.