Saab900-Plastic-ShifterBall-Until1991

This is a remake of the plastic shifter ball for Saab 900 until 1991. 
 

In the 3MF file you will find multiple build plates.
First one is optional an calibration test piece. You can use any calibration method you want - but adjust the XY hole and contour precision settings of your print profile.  The inner bore should be 12mm - the outer edge 40mm. Test this piece on the metal shift rod. It should be a very tight fit. Any wobble will be amplified on the top of the shifter.

In many cases it might already be enough to use carefully remove the lower ball of your shifter and replace the rubber ring. It has its own build plate.
TPU95HF works well for the rubber ring. To install it on the shaft, heat it up to 80°C in an oven for a few minutes. Then push it over the shaft and immediately cool it down in cold water. Be careful and don't burn yourself.

The Multipiece one is a copy of the original piece.  The only minor change here is that I increase the wall size. The spring insight the upperball will still have enough space. The Freecad source file is included. There is a ConfigData spreadsheet and if you rather want to go back to 4mm walls, you can change it there.
Once the TPU ring is one the shaft, place the outer ring above the shaft. After this push the lower ball onto the rubber(TPU) ring. Make sure the edges of the ring are not bend. When you squeeze the lower ball together - the outer diameter should be ~38mm. All my test prints that had more than 38.5mm failed and cracked quickly
 

I also recommend to use the uprated upper ball half. This is slightly modified with a longer tube to make it stronger. Like mentioned - the less play these parts have - the better. Simply exchange this with the upperball half on the Multipiece version.

As the lower ball cracked while testing many times, I ended up also creating a “OnePiece” version. Here it is important to print the upper ring in the exact place - you will not be able to fit it above the part later. I included a 0.2mm gap between the parts - which lets them print fine.

As I do not have an enclosed printer, I tested PETG, PETG CF, ASA and PLA Tough+ for test prints. Surprisingly PLA Tough+ had the best results for testing.
Ideally this should be printed in a stronger material like PAHT-CF or PPS on an enclosed printer.

Last but not least there is also a version called ShortShifter. Like before the pieces are available as multipart or OnePiece.
This is still in development. Essentially the distance between the upper and lower ball are increased by 10mm. This changes the travel and lever of the shifter. As the name indicates - it will make shifting between gears shorter - but also stiffer as you need to force. 
For this version you need to replace the three M5x20 screws with M5x30 screws or bolts. 

In the Freecad ConfigData file you could also change the value. 5mm to 10mm is a good comprise - 20mm too stiff for my taste (before I forget 0 would be the original).