Model TT Radius Rods

[Jerry VanOoteghem]

I just picked up a "pair" of TT radius rods. I put pair in quotes because they're not exactly alike. While they're both the same length and appear to be a functional pair, one has a long constant taper, while the other tapers down from the rear, going forward, then has a more pronounced stepdown. Are AA radius rods similar to TT? Would this explain the inconsistent tapers between the two rods? Neither one appears to have been altered in any way.

[67pontiac]

Hi Jerry, Like the passenger car parts, TT parts were up-dated/changed during production. There were at least 4 major changes in the car radius rods, (some people say there were as many as 8 versions). The TT had at least 2 versions. The one with the "continuous taper", (early), and one that was "stepped", (late). I know of at least one other version, but I've only seen one rod of that type so I won't go into that right now. I'm not exactly sure when the rods were changed, but I suspect it was about the same time Ford started supplying factory cabs, (1923-24). The change to the stepped rods could have been as late as 1926-27. The Model AA radius rods have a completely different casting where they connect to the differential housing/backing plate. I hope this helps some. Regards, Bill

[Jerry VanOoteghem]

Thank you Bill, that's exactly the info I was hoping for!