1980sc no longer shifts into 2nd gear

[nicfranc]

My car has been shifting perfectly until yesterday when while shifting from 1st into 2nd I was unable to make a smooth transition.
After missing the shift I could no longer get it in 2nd gear at all.

I can go from 1st gear to third but cannot get into 2nd either from 1st gear or from 3rd gear.

When the car is not moving I still can't get it to go into 2nd gear.

The bushings fore and aft have all been replaced recently and up to this unfortunate event the shifting was spot on.

From my initial research I guess the next step is to drain the transmission oil and look for metal collected on the drain plug.

If i drain and replace the Tranny Oil can I continue to drive the car by skipping shifting from 1st to 3rd without damaging the gear box.

The car has 300k miles

[Peter Zimmermann]

You are probably already on your second, maybe third, transmission. You will probably find a number of small teeth, called dog teeth, on your drain plug. Those teeth missing have allowed your second gear synchro ring to pop out of position, and it is preventing the slider from engaging the gear.

Do not try to drive the car, when the synchro ring gets loose it can cause lot's more damage. BTW; at 300K miles your trans will be very expensive to repair, unless a previous repair included new bearings, etc. More info needed!

http://porsche.wikidot.com/ Scroll left side of page, click on "915" under "page tags" and you'll find my repair Tutorial.

[nicfranc]

Thanks Peter for the guidance.
I will post the results after I drain the transmission oil.

[nicfranc]

I drove the car shifting from 2nd to 3rd and it shifted through 4th & 5th with no problems. Reverse also works perfectly.

It will not go into 2nd at all even with the engine off.

I Drove for 30 minutes went up and down through all the gears except 2nd I then
drained the tranny and pulled the inspection plate.

I drained the oil through a strainer and some small dog teeth came out with the oil.

When I removed the cover plate with the attached fork I was able to move the shift back
in 2nd gear position but not with the inspection plate installed.

[nicfranc]

I removed the inspection plate/cover and took this photo looking up at the gears.

I have rebuilt engines but never did any transmission work so this is all new to me.
Reading through Peter Zimmermann's Transmission Tutorial deciding if this is something I can handle.

I was hoping to drive through the summer but now I am concerned about the possibility of the second gear letting go and causing more damage.

[Peter Zimmermann]

Time to take a deep breath, and take it apart. Good luck with what you decide to do!

Please don't drive the car!

[nicfranc]

In addition to the obviously damaged 2nd gear synchro Ring and its slider
Anything else I should look out for "while I am in there" as far as worn parts?

Are these parts still available and made by Porsche or have they become a third party item ?

Any manufacturers to stay clear of ?

[nicfranc]

I brought the Transmission up to Gary Fairbanks up in Norwalk CT and we opened it up
and found that the 2nd gear synchro was totally shot and the slider was out of position and a piece had broken off.

I was lucky there wasn't more collateral damage.

Thank you Peter Zimmerman for your advice to stop driving the car.
It could have been a lot worse and a very expensive repair.

I am replacing the synchros and sliders for 1st 2nd & 3rd gears.

Note:
(I could shift from 1st to 3rd and 4th and 5th and had driven it a couple of times and was tempted to continue to drive it.)