Downshift 5th to 4th
 

Problem resolved after reading past post, then adjusted the shift linkage. Love this forum.

what was your problem?

Down shift 5th to 4th
 

I was hitting reverse, and hard to shift to 1st.

Same issues here, but in time i got used to the box. Sometimes hard to know what was me, and what needed adjusting. Either way, i have a wevo classic on order. I figure is is good ensurance for my engine.

On my 915 gearbox, instead of shifting diagonally from 5 -> 4,
I generally pop it out of 5th, and let the stick center itself in neutral for a moment.
Then I pull straight back, and it always seem to fall right into 4th.

Roper - can you quickly describe what you did to the shift coupler to fix it? Was it a left/right adjustment, or an up/down?

I recently installed a factory short shift kit and every gear is perfect except for the 5-4 downshift, where I seem to hit reverse when going down into fourth.

5th to 4th downshift
 

The adjustment I made was to adjust the coupler by moving it clockwise, looking forward to the front, I could feel clicks from the coupler and move it all the way clockwise. Went out for a test drive 5th to 4th ok but was having a hard time with 1st. Readjusted the coupler but this time I back it off one click, worked great. I suggest adding some blue Locktie to the adjustment bolt to prevent it from working loose. Hope this helps.
Wayne

This is great for not nicking reverse. Then there is the issue of getting 2nd when you want 4th. A Pro Driver took out all of my valves and ruined the trans by doing that. PP sells this great item to take care of not hitting an unintended lower gear. 1973 Porsche 911 T Coupe/Targa - Shift Linkage - Page 3

I had a 5th to 4th issue on my '78SC and lived with it for more than 10 years! In my case the problem was incorrect adjustment on the pinch bolt (under the panel behind the seats). Basically, the shaft was too short; solution was to slacken the bolt and carefully pull back on the gear stick, watching the pinch bolt move forward a mm at a time, thus lengthening the shaft, re-clamp bolt, do a test drive and continue this process until you can pull the lever from 5th to 4th without snicking reverse. Now works really well. Just need to improve the 1st to 2nd change and wonder if changing bushes at gear stick end would do this

So if it's possible to nick reverse while going from fifth to fourth because of a maladjustment is it also possible to nick first while going from second to third on a 915?

Yes, I would have thought so; it suggests that the shaft is too long so try my fix but push the gear lever forwards to shorten the effective length of the shaft. Would have thought you might also have a problem shifting 4th to 5th?

I have nicked 5 to 4 while downshifting aggressively but I have never nicked 1st while shifting from 2nd to 3rd. This was the reason I asked Roper what his fix was, even in aggressive downshifting I should not be hitting reverse. Looks like I will need to go in and make a slight adjustment.

Perhaps the gear shaft on your car is too long. Try shortening instead of lengthening it using same method. Would have thought there might be a problem nicking 3rd when going from 4th to 5th also?

I never nick reverse going from 5 to 4.
I agree that means something is wrong with the box, or he is shifting incorrectly.