I’ve been following the post where the shift selector linkage rubber is removed and replaced with Delrin rods.
I also saw a post where someone is manufacturing a new solid part.
And I’m aware that
Porsche
eventually went to a solid part in their later cars.
I’m also aware there might be a little bit more NVH but I’m willing to sacrifice.
That’s why I decided to make the existing part on my car solid using about five dollars worth of hardware store stainless steel hardware.
For the selector plate modification you’ll need two 6 mm x 25 mm 1.0 pitch stainless steel
cap
screws and matching Nyloc nuts.
You will remove the selector plate from the Car, then drill two holes in it, then grind the rivet off of the plate and disassemble it, removing the rubber sandwich and then rebuild the plate using the two
cap
screws. If you have a welder, you could weld it solid.
The transfer rod is made up of Parts purchased from McMaster Carr
2 of these:
9424k56
Corrosion-Resistant Gas Spring End Fitting
Ball Socket with Clip, 316 Stainless Steel, M8 x 1.25 mm Thread, 0.59" Wide
1 of these
6516k329
Connecting Rod
18-8 Stainless Steel, 150 mm Overall Length, M8 x 1.25 mm Thread
2 m8 x1.25 SS hex nuts for lock nuts.
There’s resources online for removing the selector plate so I won’t go into great detail here. But I did make my own puller out of a ball joint puller by slotting it so that it would fit over top of the transfer rod ball joint. I happen to have a milling machine in the garage, so it was easy to modify this tool. If you would like to use this tool message me and we will work something out.
Just know that the common advice for a windshield arm puller did not work. There is no way the windshield arm puller that I purchased would fit and I don’t believe it would have the strength to remove the selector plate. It was on there very firmly.
Once you get the selector plate off drill two holes in it, pop the cap screws through and bolt that sucker solid. I ground the rivet off and remove the rubber pad from the inside as well, but I don’t think you really have to.
If you aren’t going to change the crossover rod, then you can just bolt it back up and connect the cables back up. I did not reconnect the flywheel and like the way the car feels.
If you’re gonna build a connector rod, wait to install the plate.
You’ll take the old connector rod piece of plastic and lay the ball ends so that they align with the holes in the end of the piece of plastic. (see picture of rod above resting on plastic part.) Then mark the threaded rod at each end cutting the appropriate amount off so that you can match that dimension. Hacksaw and file should work. I happen to have a lathe so it was super simple.
Build the selector shaft with lock nuts, and red Loctite, making sure that the faces of the ball joints are in the same plane and the length is as close as you can get it to the length of the original connector.
Now reinstall the rod to the selector plate and install and latch the locking pin.
Before you do anything else, take a quarter inch wide piece of masking tape and install the locking pin on the other ball joint with just enough of the pin in the hole that you can still push the ball joint onto the ball then tape the pin in this position using the least amount of tape possible.
You will not be able to reach it to install it in the tiny hole from underneath the car unless you have miniature hands.
Now reinstall the selector plate, feeding the rod across the top of the transmission. Reinstall your left side shift cable. I chose not to reinstall my flywheel linkage. If you don’t like it, you can put it back on laying behind the car on.
Now going around to the right hand side of the car, carefully align the connector rod with the ball joint and slip it into place. Now carefully push the pin all the way through and lock it into place. See how the tape saved you lots of agony?
Double check all your bolts are tight, and your cables are well connected. Inspect that your shifter should be in the same location as it was before.
Go for a test drive.
I found the precision was greatly enhanced with less than an eighth of an inch of free play in the shifter, using numeric shifter, and numeric cables in this mod. The action is truly rifle bolt in nature, with a very precision, mechanical feel, and slightly louder shifting sound.
This is pretty wild,
@Ric_in_RVA
. Great job. This is definitely something I'm going to play around with, at some point when I have the time. Great write-up, Ric.
I happen to have a Mill.
I happen to have a Lathe.
A man after my own heart. Those things happened into my workshop as well!
what is the “flywheel linkage”? (Apologies for my ignorance)
At the back of the trans is a flywheel that is attached to the linkage. I believe it is there to add mass to the system to damp out vibrations and to give the shifter a certain feel. I don't think it is required to be there for any other reason. (but if you do please tell me!!!). It has a simple plastic connector and you can pop it off. Once off I feel like the entire linkage feels more mechanical and precise. Easy to try removing and replacing. I can even do it with the car on the ground. I'll probably remove the weight one of these days. I know in later cars that mass got machined own into a smaller unit. I may experiement with that eventually. My plan now is to drive without it for a while....re attach and see if I like it with the weight then. I am loving the
numeric
shift/ cable/ solid linkage feel as it is.
The mill and the lathe has been a life saver for me as an inveterate tinkerer. The are old and not exactly precision any more with some slop in the screws and ways, but work for my needs.
Let me know and I'll share the
puller
with you. We should have a tool lending program on this site. I figure I'd collect a deposit, ship and then refund all the costs less my shipping cost when I get it back. If it never comes back I keep the deposit and you bought a tool!
Awesome work! I'm also in RVA, so I may have to hit you up to borrow that tool when I do that work.
