Steve, asking for an opinion here. I've got an essentially stock '84 Carrera 3.2 coupe. Currently has 161,000 miles, and I've got full service history going back to new (despite having 8 prior owners). Window sticker indicates it was built with limited slip, which I've confirmed is still present. Only mods over the years have been DME chips, currently running one from Steve Wong. The car has been well maintained throughout its life, not abused, no track time (that I can confirm), and is a good, reliable driver now.
My question about the 915 (and the reason that I felt I needed to confirm the LSD was still present) stems from the fact that the transmission has been rebuilt no less than 3 times so far. Each time it was rebuilt by established Pacific NW Porsche specialists.
First rebuild was at 75,000 miles, by John Walker. In addition to the normal things (synchros, sleeves, etc.), JW replaced both 2nd and 3rd gear sets, with the note that they were "damaged from 2nd synchro explosion."
Second rebuild was at 130,000 miles, by Paul Weir. Of special note on this one is that PW replaced transmission case.
Most recent was only 13,000 miles later, at 143,000 miles by Motor Sports International. This one appears to have been just the normal synchros and sleeves.
Don't get me wrong, the car doesn't exhibit any transmission issues at this time, other than being a bit noisy overall. (But this is my first Porsche, what seems a bit noisy to me may be perfectly normal for a 915.) Seems to shift fine. It does have a factory short shift in it, as well as a Seine Gate Shift kit and delrin coupler bushings. (I am keeping my eyes open for a stock shift tower and lever, might like to try it w/o the short shift.)
But as I drive the car regularly, should I be concerned? Do I need to begin saving for the next rebuild? Or am I just being paranoid?