Brass shifter bushings in the 915 trans coupler questions

[dictoresno]

tackled the shifter coupling bushings today. the car gave no inclination that they were worn and actually shifted fine, with only 49,000 miles, but decided to go with brass bushings instead of the stock rubber/plastic or Delrin. Turns out, they were completely shot. swapping the originals were straight forward. however marking the shaft in its original position hindered me from shifting from 1st and 2nd and also into 5th. I guess the amout of slack in the brass, which is unforgiving, required me to relocate the position by about 4 splines in order to get all shift planes back to normal. feels much nicer now.

The rubber boot that attaches to the rear of the shaft by the firewall was expanded and popped off its lip so I cleaned it and re-coiled it back to position and reattached it to the hole to the engine bay. the other boot over the coupling just needed some degreasing and cleaning. I included a video of how bad the coupling was.

my main question is when doing these, especially with brass bushings, is it necessary to shim for minimal play? after watching some videos, I saw some users using a very thin arbor shim (0.008 inch) to take up most of the play between the brass bushing and the splined pivot while still allowing for proper up and down movement. I used one thin shim to tighten it up and it isn't impeding the flexion of the joint, but it's probably not as loose as stock with just rubber bushings. after readjustment, I can hit all gear planes and shifting seems fine, but just want to make sure its going to be ok with the shim for the long haul. Lubed up with some Ballistrol, the pivoting arm and the pressed in pin rotate together freely within the brass bushings.





https://youtube.com/shorts/sKHJDl3kV50?feature=share

[Alan L]

I just did the same a couple of days ago. I used the delrin type bushings (Pelican) - which is a slight issue, becasue when you press the cross pin in, you press against the delrin. So the gap opened another 10 thou or so. I marked my spline and it went back perfect in the old spot. But yes, any slop you can take out of the cross pin movement will be beneficial. I did wonder about that at the time also and I have about 20 thou slop. But it is shifting perfectly and precise. One of my bushes was completely gone.
Didn't know the brass bushes were available, but I think these will see me out. In fact I could have made them (brass) myself.
Alan

[proporsche]

just little info-those brass bushing will transfer extra noise form transmission.....Teflon is just fine , it will last you another 30 years

ivan

[ErrorMargin]

I installed the brass copper bushings and I used the stock shift rod bushing and the shifter to shift rod cup bushing.

I did not use any shims.

With all three bushings replaced shifting is very precise and there is no extra noise (that I can detect) coming into the cabin.

I followed the steps in this video:

https://www.youtube.com/watch?v=wAeo_qNCehY

[Shaun @ Tru6]

I've used brass for years, they are plug and play.

[dictoresno]

Guess the shim wasn’t really needed but I had proper flex in the shaft. I guess if I find it binding up I’ll remove the shim.


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