1985 Nissan 300ZX with Transmission Problems

The transmission feels like its slipping while in drive. Oddly though, it shifts great using 1st to 2nd to Drive, then using an on / off switch to control 3rd to Overdrive/4th. Its automatic and I am just using the shifter to control shifting, because the car doesn’t seem to downshift on its own either. It will stay in Overdrive/4th even at 35mph with the pedal to the floor, only sometimes downshifting after awhile. The car also hesitates slightly while driving at above 65mph on highway. It stops doing so on hills, and it has no issues at lower speeds, even at 5k rpms. Not sure what that is related to. I just bought it, and the transmission fluid is black, not sure if its from lack of maintenence. I assume the transmission needs a rebuild, but the more I know the better I won’t be ripped off at a shop. Please let me know what you guys think might be wrong with the transmission/engine so far. Thanks.

Black transmission fluid=Burned up transmission. Time to rebuild/replace.

transman

Odds are the transmission is dead or close to it. Black fluid means that the fluid is burnt and full of friction material from the clutches.

You should also consider that the transmission, unless it’s been rebuilt in the past, has rubber seals and O-rings in there that are a quarter century old and rubber is not going to last indefinitely.
This leads to fluid pressure loss, slipping, and the black fluid that is mentioned.