1991 civic dx hatchback

Automatic transmission jerks/clunks when down shifting from 2nd to 1st gear. Especially if I come to a rapid stop, the tranny seems to drop hard from 2nd to 1st. Also, it revs high and doesnt want to shift when accelerating from 2nd to 3rd gear, eventually it does shift.

The downshift jerk is much worse and repeats, while the other issue only happens sometimes.

I changed both front and rear mounts, which were completely shot, but it did nothing to solve the problem.

Is the tranny shot or can something be adjusted? Does the speedometer sensor gear affect shifting? Or the transmission cable?

Its a newly installed used japanese import tranny.

 

Have you tried replacing/flushing the transmission? A lot of automatic transmission issues are resolved from running good fluid.