Forward Shift Ball Cup replacement- The easy way
#16
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#18
Drifting
#19
Developer
This is a WYAIT thing. Sort of like "WYAIT replace the steering rack mounts when you replace the motor mounts"
We recommend to replace the forward shifter ball cup WYAIT replacing the motor mounts, as in the moments after you have taken the motor mounts out, you can lower the engine making much more room above the TTube between the TTube and the body. Also, remove the air filter box on early cars - you can actually get fairly good access to the shifter ball cup from the top on some cars.
OR
If you drop the TTube for any service, WYAIT replace both the front and the rear shifter ball cups.
Our instructions for installing that part are located here: https://928motorsports.com/installpd...CupInstall.pdf
We recommend to replace the forward shifter ball cup WYAIT replacing the motor mounts, as in the moments after you have taken the motor mounts out, you can lower the engine making much more room above the TTube between the TTube and the body. Also, remove the air filter box on early cars - you can actually get fairly good access to the shifter ball cup from the top on some cars.
OR
If you drop the TTube for any service, WYAIT replace both the front and the rear shifter ball cups.
Our instructions for installing that part are located here: https://928motorsports.com/installpd...CupInstall.pdf
#21
Drifting
Eventually I found a tool I could use to pop the socket off, in conjuration with a hydraulic jack
The hack saw didn't survive the process
The next problem was to remove the old nylon cup
In the end I levered it out with a large screwdriver, making a bit of mess of the metal receiver
Then I had to find a way to press in the new nylon cup, which is a very tight fit
First I tried to use a stubby wrench to undo the lock nut, not a chance
So in the end I used the ratchet strap to pull the link in to a position where I could press in the cup
The only easy part of the job was using the strap to refit the cup on to the ball
The total number of hours I've spent on this so far (I haven't even put the exhaust back) is probably beyond belief
There is definitely very little that I would describe as easy about this job, and what's worse I can't actually feel any difference in the gear lever
The hack saw didn't survive the process
The next problem was to remove the old nylon cup
In the end I levered it out with a large screwdriver, making a bit of mess of the metal receiver
Then I had to find a way to press in the new nylon cup, which is a very tight fit
First I tried to use a stubby wrench to undo the lock nut, not a chance
So in the end I used the ratchet strap to pull the link in to a position where I could press in the cup
The only easy part of the job was using the strap to refit the cup on to the ball
The total number of hours I've spent on this so far (I haven't even put the exhaust back) is probably beyond belief
There is definitely very little that I would describe as easy about this job, and what's worse I can't actually feel any difference in the gear lever
#22
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Well, I did finish and I have also installed the metal shifter ball cup. The house is made of aluminum and the concave screw of stainless steel (the ball in the picture is for testing only). I must say it was kind of tricky to install the ball cup without lowering the torque tube but after a lot of cursing it was in place. I had to make a couple of special tools in order to tighten the lock nut. When I was there I took the opportunity to manufacture an aluminum short shift lever. Earlier I had fixed the rear shifter coupler with bronze bushings. I am still doing work on the blue car but I had the opportunity to test drive it with the improved shifting mechanism and I am happy with the result, short shift, very distinct, no rattling, no uncomfortable vibrations.
Åke
Åke
#25
Rennlist Member
Beautiful machining and fabrication!
#27
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Hi Ake,
Nice work as always.
I used to supply the brass bushings for the rear coupler but most of our customers found that they made a "sizzling" noise at the shifter.
We changed to "round hole" poly bushings and the issue went away.
Hope that helps.
Best Roger
Nice work as always.
I used to supply the brass bushings for the rear coupler but most of our customers found that they made a "sizzling" noise at the shifter.
We changed to "round hole" poly bushings and the issue went away.
Hope that helps.
Best Roger
__________________
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission? George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission? George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
#28
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Åke
#29
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Åke --
"sizzling" is the high-frequency buzzing noise that frying bacon makes. Every tiny vibration in the engine or gearbox rattles the shift rod. Your adjustable clamp over the ball lets you eliminate the clearance for rattles and buzzing at the front. For the rear coupling, you could pack the joint with grease and clamp it in a section of rubber hose to eliminate the noises. Oillite bronze bushings (impregnated with lubrication) would work if the gaiter/boot was installed correctly to keep it all clean.
Curious if anybody or why nobody has tried to replace that front joint with a Heim joint (spherical rod end) for this duty.
There's a good reason why Porsche "shifted" to cables and little bellcranks for road car shift management. Noise transmission into the cabin is dramatically reduced, with virtually no reduction is "feel" for the driver.
"sizzling" is the high-frequency buzzing noise that frying bacon makes. Every tiny vibration in the engine or gearbox rattles the shift rod. Your adjustable clamp over the ball lets you eliminate the clearance for rattles and buzzing at the front. For the rear coupling, you could pack the joint with grease and clamp it in a section of rubber hose to eliminate the noises. Oillite bronze bushings (impregnated with lubrication) would work if the gaiter/boot was installed correctly to keep it all clean.
Curious if anybody or why nobody has tried to replace that front joint with a Heim joint (spherical rod end) for this duty.
There's a good reason why Porsche "shifted" to cables and little bellcranks for road car shift management. Noise transmission into the cabin is dramatically reduced, with virtually no reduction is "feel" for the driver.
#30
Pro
The fun is going to be determining just how best to secure the joint to the torque tube, and if the existing ball mounting point can be reused to mount the Heim joint.
I would need to do some digging to verify just how much rotation that the current shift linkage allows, since Heim joints are limited in their misalignment angle. A quick bit of digging turned up some interesting material, including some manufacturers offering "high misalignment angle" joints, but even the "high" options don't give you a huge amount of added play.