Shift Rod Coil Pin Hole ? Options

[cary]

Good Morning,

Yesterday was supposed to be the day Mike drives off in his freshen up 72 daily driver.
Didn't quit go as planned ................ I finished the shift rod install before lunch. Then he and his right hand man, O'Ryan went about installing the hoods. Then it was time to dial in the shift linkage adjustment. Set about using what I call the Chris Neutral adjustment. Has work flawlessly for a long time. Not This Time.


Looks like Chris might have been converted to the 4th gear club.


After more time I want to admit (or charge for) we couldn't get it to completely shift into the 1-3-5 plane. Pulling my hair out ............... this isn't supposed to be that tough. Long story short. Finally determine its not the linkage adjustment. I have a nice and tidy neutral. Can feel all gears. Just won't stay in lower plane. So we finally pull off the shift cover. Remove the shift rod. Then go about shifting the gear box by hand. Still no lower/back plane. Gear box is toast. (IMG:style_emoticons/default/ar15.gif) (IMG:style_emoticons/default/ar15.gif) (IMG:style_emoticons/default/ar15.gif)
Mike is amendment it worked great when he drove it in San Diego and when he drove it up here years ago. (IMG:style_emoticons/default/idea.gif) (IMG:style_emoticons/default/idea.gif)

So I grab the ball pin and watch it turn. Guess what. The ball pin is turning and not the shift rod. That don't look right. So I go over and check other gear boxes standing in the corner. No Play. Hmmmmmmmmmmmmm. I did have a coil pin, not just a roll pin.







Shifted great last time I drove it : New Data Points

• Gearbox has been moved into a 72 tail shifter tub
• All the linkage was moved from the shifted great last time car and installed into 72 tub
• New Tangerine Racing firewall bushing
• New GPR Oilite Bear Bracket bushing

Pin was tight drifting it out. But only in the ball pin I assume.

The hole seems to be wallered up and down. Can it be fixed ?

New 6 * 31 coil pin ?

Can I enlarge both holes to accommodate a 1/4 * 1 1/4 coil pin ?

Brain Trust : Whats been done before ?

[Bartlett 914]

If you have boxes in the corner, remove a shift console and swap it out. This will require draining the oil.

[ChrisFoley]

If you have boxes in the corner, remove a shift console and swap it out. This will require draining the oil.

(IMG:style_emoticons/default/agree.gif) This is the easiest way to resolve the problem.
The gear oil can be re-used if it's drained into a clean container.
If no spare is readily available, you need to ream the holes to the proper size for the next larger pin.
A snug fit thru both components is important. A force fit is bad, and any looseness will accelerate wear.
A solid pin can be used but fit and alignment are more critical.
New gear selector shafts for the console are available from Porsche but aren't cheap.

[cary]

I'm not a tranny guy. I've got people for that ......... LOL
That was one of my first thoughts. But it looks like the shaft is pinned again inside the box. (IMG:style_emoticons/default/sad.gif) Or does that whole thing slide in and out ?

[ChrisFoley]

Looks like Chris might have been converted to the 4th gear club.

Either of the two methods work well to get the alignment close enough for a test drive.
With one of my Precision Shift Adjusters installed I do the initial setup in second gear.

[ChrisFoley]

Part 14 at the top of the shaft is a critical component, also subject to wear that exacerbates sloppy shifting. New ones from Porsche are pricey.
The shape of the "comb" is important to smooth transition from one gear to another.

[ChrisFoley]

I'm not a tranny guy.

Drain the box and remove the console. Reinstallation is easy but the shaft must be aligned correctly on the way back in.
It's good practice, and you should be prepared to replace the o-ring and shaft seal for your customers when their boxes drip there.

[cary]

Ok ............. you've perked my interest/curiosity.

Not going to touch the one that my boys call my best shifting box. But I have a side shifter I got in a Montana garage clean out. It will be my victim.
Mark probably wouldn't like me stealing the one out of his project car box. LOL.

I assume neutral in and out ?

I'll stop at Ace from some roll pins too.

[ChrisFoley]

I assume neutral in and out ?

correct

[PlaysWithCars]

Swapping consoles, while not difficult, is messy and does take time. And, when done you'll be left with a good shifting trans in the car and an incomplete trans on the shop floor. If you want to reassemble the one on the floor you're going to need to deal with the old console. Why not just ream for the next larger roll pin withe the console still in the car? If I recall correctly there should be enough room. Ultimately less time and less mess than the path you're pursuing and you don't run the risk of introducing new oil leaks.

[914Toy]

What size should the hole be reamed out to and what size coil pin replacement?

[PlaysWithCars]

Classic engineering answer: it depends. (IMG:style_emoticons/default/dry.gif)

Search Google for "coiled spring pin" and there are numerous manufacturers that give hole size based on the size of the pin you're using. The OP shouldn't need to enlarge the hole much beyond the original size. What the final hole size will be is dependent on how enlarged the current one is and what size coil pins are available to him.

[cary]

Hmmmm

On the way out to the shop I stopped for some coil pins. No luck just roll pins.
Both 1/4 and 6mm.
First Data point in my head. The PET calls outs a 6 * 32 roll pin. The coil pin the came out was 5.79xx and really worn in the middle.


The roll pins I bought had on OD of 6.02mm. I enlarged the hole in the ball with a 15/64 drill bit. 5.9531mm.
Hole started at 5.831. Not too much but the new 6mm wouldn't start. After running the drill thru there the new roll pin fit nicely, though a little short. They only had 30mm. So I installed it back on the transmission and gave it a go. Thus time I couldn't see any movement with the naked eye. (IMG:style_emoticons/default/biggrin.gif) Installed the shift rod back on, time for a test. The lower plane shifts feel a little better. So I give it the test. Will it stay in gear ?
Start the car in 3rd. Pops right out. Start the car in 5th. Pops right out. Time for a time out. Short day, heading to a birthday dinner ............

But I pull down the spare gearbox and start draining the oil. Only to find out its stuck in 4th gear. (IMG:style_emoticons/default/mad.gif)


The battery in my micrometer was giving me issues so a little shy on numbers.
Here's the info on coil pins.
https://www.spirol.com/library/sub_catalogs...led_Pins_us.pdf

[ChrisFoley]

Start the car in 3rd. Pops right out. Start the car in 5th. Pops right out. Time for a time out. Short day, heading to a birthday dinner ............

Have you verified no interference at my firewall bearing?
This is a known potential interference point with a possible need to clearance the front of the knuckle.
We had a car not too long ago that we did this and it still didn't stay in gear.
A little different alignment of the forks on the shift rods in the gearbox can accentuate or mitigate this interference.

The only way to make the bearing fit without any possibility of interference would require cutting a shoulder on the aluminum housing and cutting a hole in the firewall large enough for the housing to seat partially into the firewall. (Like Euro911 had done)

Of course, my shift linkage kit eliminates any interference.

[Dr Evil]

Also, recheck shift alignment. If your stick cannot transition far enough aft then you will see issue with 1/3/5. If you adjust your stick to give some more travel to the aft (as noted on the shifter at the transmission), this may solve your problem.

As for the other box stuck in 4th, not a big deal. Drive out the roll pin that you are now intimately familiar with, pull the console housing while leaving the console rod and shift comb in the box. Then, once the console is clear, just wiggle the rod/comb out of the hole. You can then shift the box into neutral using a screw driver.

[cary]

Also, recheck shift alignment. If your stick cannot transition far enough aft then you will see issue with 1/3/5. If you adjust your stick to give some more travel to the aft (as noted on the shifter at the transmission), this may solve your problem.

We worked that pretty hard on Saturday, didn't do too much.
Didn't have enough time yesterday to tinker with it after I put in the tighter pin.
Onward and upward.

Jeff said there quite a bit of side shifter parts up in the South Mezzanine. Didn't have time to search today.

[cary]

What remains of Rothsport stash.

[ChrisFoley]

Ed reminded me that we've seen that ball end welded to the shaft at least once before.

[cary]

I took the tightest one from the Rothsport collection. Plus the loose rod and hardware.
Than ran the old MiddleMotors spare thru the jet washer a few times to get it cleaned up.
Then went ahead and pulled the bearing bracket without the rod from the spare. Once the bracket was out of the way, the rod came right out. Into the jet washer they went.
Just like Doc said.

Seals and pins are inbound.

Then went ahead and drained the Swepco out of Mike's gear box.

So here's where we're at :

Wednesday night Mike and I had a moonlighting session using a tighter pin from the Rothsport stash. I adjust the linkage so I have the longest rearward shift I can get.
Still the same. Won't actually shift into 1-3-5. I can hold it in gear pulled back on the shifter. But not really engaged.
So I unbolt the all the linkage and move it out of the way. Now I attempt to shift into 1-3-5 by hand. No go ............. Just wont go in. (IMG:style_emoticons/default/hissyfit.gif) (IMG:style_emoticons/default/hissyfit.gif) We're done for tonight, lets go home.

So last night after I drain out the Swepco I can shift into 1-3-5 without an issue ... (IMG:style_emoticons/default/headbang.gif) (IMG:style_emoticons/default/headbang.gif)

The only other tidbit to add. Gordon Ledbetter stopped by Rothsport on Monday and I ran my issues past him. Without seeing and feeling it he didn't have much to go on. But he did say both pins have to be tight with zero play. And you need both the upper and lower washer. Upper washer is NLA. Lower available used. I don't think any of the shift rods have the upper washer on them.

[Bartlett 914]

Without the engine running, it can be difficult to engage gears sometimes. Was this tranny recently worked on? Did you install a gasket between the shift console and the case? There shouldn't be one. It is sealed by an O-ring