normal operation man.....I get that too, occasionally, and I know of some other 230jm/jk men who have expressed similar concerns.....that's just how it goes in and it appears to be harsh.....your bad mounts would have made it feel very bad, as if transmission is going bad or malfunctioning.....at some speeds if the 4th gear does not get to go in, the car would feel at times as if it wants to "buck"....so I just switch it to 3rd and all's well......I however think that I need to change my fluid......
but anyway, check your trans fluid and if it needs to be changed the motorist/massey recommends that you use this.....

$52 a quart....you'd need about 8-10 quarts.....