I’m having a very odd issue, it happens randomly but I’ll start my xj up let it warm for a minute and let idle come down, when I put it into drive it will jolt or bang into gear than my 1-2 shift bucks or jolts the car hard like a really hard bang either coming from the rear or the tranny, after about 5 mins of driving it goes away and it shifts smooth as can be, other times I can start the car and go and no problems, it’s been happening awhile and it worries me as I have a 500 mile round trip road-trip coming up any suggestions?
Stock 4.0 240k miles
I flushed the tranny fluid and put a new filter in about 4-5k miles ago
could It be that the tranny fluid isn’t circulating correctly?

 

Year?

 

Which fluid did you use?