I’ve got a 1993 Civic Del Sol (love it) - it has 130k on it and for the most part the automatic transmission works well, except on cold mornings.
Until it warms up it will not shift out of first gear. When it is misbehaving in this manner there is a siren like wining of gears that increases as you attempt to go faster.
While at speed, if you put the transmission into neutral the sound continues at the same level so it’s connected to the vehicle speed, not engine. Other than the differential, I’m not sure what is in the drive train that is ‘in front’ of the transmission.
Once the transmission has warmed up enough, it will make a chuncking sound not unlike synchronizers being forced to mesh on a standard transmission and once the ‘chunk’ noise occurs the transmission will shift normally. If I let the car warm up first (5 to 10 minutes), I will not encounter this issue.
Here is a link to the sound if you want to hear it.
I’ve checked fluid levels, the fluid was changed probably 30k ago if I recall correctly.
Any suggestion / tips appreciated!