When I started this, I thought maybe I could hear a bit of rattle in my gearshift, and thought maybe I needed a new antirattle spring and plunger. I had seen them in the roadster factory catalog, and read about them on the forums. I had also read about problems holding them in place while installing, oversized springs, problems getting the steel retainer off the aluminum gearbox housing, and so on.
It turns out my spring and plunger were fine, once I understood exactly what it does. When you push and pull the gearshift lever forwards and backwards, you should see about 1/8″ of play, and feel the little spring compressing through that range of motion. I show this at the beginning of the video.
Here is a summary of what I found:
1. TRF sells a substitute spring – actually a syncro spring – that is too long. It should be cut so the spring is maybe 1/32″ shorter than the hole it sits in. Just enough for the plunger to sit in the hole a little. I reused the original once I understood how it works.
2. I had little trouble with with steel retainer – the piece that defines the shift pattern, It came off with some tapping on each side with a hammer. I used antiseize putting it back on.,
3. I found all you need is some grease to hold the spring and plunger in place. Just don’t turn the gearshift lever once it is installed, or the plunger will pop out.
4. I used Mobil 1 Red synthetic grease to lube up the parts.
Here is a video showing the parts, how they fit in the gearshift lever, and installation.
TR3 Restoration Lessons Learned 