Most Porsche 964 and 993 owners experience failing gas struts on the luggage and engine compartment lids. The result is that the lid falls into your head when you check the oil or put in the luggage. It is easy to avoid this with a half hour garage job.
It seems that these struts last for about 5 years, probably depending climate and on how many times the lids are opened. The quality of the spare part is sadly not much better than the original. A bad strut will especially be noticeable in cold weather. We have seen some that use aftermarket struts with higher pressure, some like this, but we also have seen damages on the strut fasteners and lid when it pops up in light speed when you pull the lever. We use only the original Porsche part as spare.
It is fairly quick to change the struts. Use a plank or broom to hold the lid while you are in there.
The struts are fastened with a metal clip on top, and the lower is a ball joint. Use a long flat screwdriver, and turn it as a jack to force the joint out of the ball. One or both struts have a plastic sleeve that needs to be removed from the old strut and fitted to the new one. Remember to put a small blob of grease in the ball joint before refitting, it makes it a lot easier to reinsert.
It is a bit more cramped conditions back here compared to the front. The struts are fastened with a bolt and metal clip in both ends. Be sure to hold on to the parts when you dismantle them, you do not want to drop these small parts down into the abyss of the engine.
Part numbers are for the 993 coupe, other part numbers for the Cabrio, Turbo and RS models.
Gas strut for luggage compartment (1 pcs): 993 511 331 00
Gas strut for engine compartment (1 pcs): 911 512 331 01 N