Doesnt seem like there is much information/experience with the pre 80s transmission unfortunately.

Ive had an auto transmission die on me before, an A602 out of a 3.3l Dodge caravan. That transmission was hurt when I got the van and I nursed it back into functionality for another 2 years before it finally died. That was a slow and gradual failure. This by comparison was a quick failure. My gut instinct is "something broke" instead of "something wore out". But what that something is I have no clue, and with (seemingly) light info on the older transmissions I am very blind to what that could be.

junqueyardjim.... The car was in an accident in 2000 as indicated by the service records. Car was repaired fully under insurance to the tune of $6000. The engine was fully rebuilt in 1995 to the tune of $5500. The body is straight and the alignment holds well. The paint is a little faded and there is a bit of an "oops" around the fuel filler where the biodiesel kinda ate away at the paint a little. The engine runs strong with very little startup smoke.

I have so far....replaced the dash with a non cracked item, replaced all the other interior surfaces, newer front seats (that are a bit ass worn, but not ripped too shreds) mind you..these are coupe specific items. 1yr old Bilstien HDs, new rear calipers, new engine mounts/dampers, adjusted valve lash, diesel purge, rebuilt injectors, replaced broken swaybar linkages, the usual repeated fluid changes. Oh yes, I replaced the tri-star hood ornament as the original had broken off(This is the greatest achievement Ive done according to the GF). The only things that dont work are the A/C and the climate control system(stupid ACC servo and wtf vacuum system?).......oh yeah, and the transmission.

Honestly, I like the car. A lot. I would be more than willing to put more sweat equity into it. However, assuming $3000 minimum for a rebuilt transmission and installation..thats a fair amount for (as you mentioned) a 30yr old car with 30yr old parts. Ive seen listings for newer cars for the same outlay of money. We will have review our options on this.

rs899...the slippage has always been on cold days and cold startups getting out of the driveway and never at any time. This however may be a moot point though if theres nothing that can be done with the transmission

Gavin