1978 SC Targa popping out of first gear on it's own
 

Hi all. New to the forum but have owned a 1978 SC Targa for several years. Other than oil changes and a belt change, have done very little to the car. Also, i am by no means a mechanic nor will i pretend to be, nor do I play one on TV. I just love Porsches and love to drive, 2 things that go very well together.

The car likes to shift out of first gear on it's own. Seems to hold when accelertating, but I couldn't move around a parking lot without holding it in first. It pops out, does it often, and doesn't seem to be related to a warm tranny, cold etc. I would imagine the answer here is known to anyone who has any sense at all about cars and I turn to the experts on the forum. I live in northern NJ as well in case anyone happens to know of a great shop that understands these cars and could help me out. Thanks to all in advance.

5% chance that it's linkage related. Check to see if the base of your shift lever (the few inches below the bend) is vertical. If it is, go to 95%...

95% chance that your synchro ring is worn badly enough that it can no longer hold the gear engaged.

Find a shop that has at least one 50-year-old mechanic; he'll be the one who you want to speak with! If you need help, check the PCA (Porsche Club of America) web site to see who the tech director is in your area. Call him and get a referral for a shop near you. Best of luck with it!

Just went thru this. Most likely the synchro hub as opposed to the ring. Probably going to find some dog teeth missing. Once enough are gone it won't stay in gear at all. If you don't hold it does it kinda pop right out with a bang as soon as you start to let the clutch out? If so, almost certain it's the hub.
Pretty easy & relatively inexpensive repair as far as trans stuff goes. Do need a press to separate & then reinstall the hub to the gear.

Good Luck

Thanks everyone - I will get this checkout - thanks for the quick responses.

+1 on the synchro, eventhough I would assume you will have issued engaging rather than unwanted "pop out".

I only have my 911 for 2 years, but I found the lever assembly weird at minimum. The coupler under the lever and the "cross" coupler below the back tunnel cover seem to require maintenance and loose alignment often. Or maybe its just my girl?

If you were aggressive with the 1st gear, it may have damaged the teeth and that could cause the gear to disengage.