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Thread: Porsche G50 Shift Linkage

  1. #1
    Champion Member Manta22's Avatar
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    Porsche G50 Shift Linkage

    I have put more work into my shift linkage than I should have but I want to get it right. I replaced the mild steel tubing that I used for my shift rod with ground & polished Rockwell 60C and it really improved the back & forth motion- far smoother and easier. I was pleased with those results but the shaft rotation in the Thomson linear ball bearings was not as good as I wanted. Fore & aft motion allowed the ball bearings to roll in their tracks but shaft rotation resulted in the ball bearings skidding across the surface of the shaft instead of rolling. My mistake. I pulled those bearings & housings out and made plain bearings from some UHMW polyethylene and the feel was not bad. However...
    Just by accident I found that Thomson also makes Flouroplastic- lined plain bearings in housings that are the same size as their ball bushings. I ordered some and tried them on the G & P shaft- perfecto! Now I'm replacing the ball bushings with the plain bearings. I'm not finished yet but this looks like the best solution so far.
    The shaft and bearing ID are very precision so they allow only +/- 0.5 degrees of misalignment. I installed the bearing housings as close to alignment as I could and then loosened the screws holding the bearing housings to allow them to "float" just a little to make the bearings "self- aligning".
    Click image for larger version. 

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    Regards, Neil Tucson, AZ

  2. #2
    Champion Member Manta22's Avatar
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    More Shift Linkage...

    I made another small improvement to my shift linkage. The end of the shift rod has a 1/2" 6061-T6 right angle piece that functions to rotate the transaxle shaft and push it in & out. I used an aircraft counterbore to make a 3/4" hole for the 0.750" shift rod. It turned out the hole was bored about 0.020" oversize so I used some 1/4-28 set screws to secure it to the shaft. This worked OK but I thought that I could reduce the chance of rocking back and forth when shifting by adding a second thickness to it. By bolting the two pieces together with a 5/16-24 Ti bolt, the two pieces are held rigidly together. So far so good...

    Click image for larger version. 

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    Attached Thumbnails Attached Thumbnails Shift Linkage 1.jpg   Shift Linkage 2.jpg  
    Regards, Neil Tucson, AZ

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