When I drive my 1996 Honda Accord the transmission slips or shifts hard when changing gears. I am not sure what the problem may be but about a month ago I had a bad distributor that was leaking oil onto the transmission. Can this cause problems for the transmission? I have replaced it with a new distributor but the transmission still slips or shifts hard. Would I just need to do a transmission fluid change/flush?

 

If you have a 5-Speed and oil found it's way down into the clutch assembly, then yes, slippage can occur, however, if you have an automatic then your transmission is suspect.

 

It's an automatic transmission. I'd say it slips probably half the time and sometimes it's barely noticeable. I don't want to do further damage and want the slipping to be gone so that is why I'm seeking a solution.

 

How long since the transmission fluid has been changed?

 

I'm not sure cause I bought the car used. When I check the transmission dipstick the oil is a very dark brown color.

 

Change it now, change it next weekend, and change it again the weekend after. Doing that may allow you to get a few more miles out of the tranny, but at this point, nothing is a guarantee.

 

While changing the trans fluid - BTW I highly suggest using Honda Trans fluid - check the throttle control cable (this runs from the TB to the trans) for proper adjustment and movement.

 

I wouldn't rule out that if external trans components get dirty or oily that it might be the source of the problem. I had an instance for several days that my trans wouldn't shift. It hung up and didn't shift out of second and third, up until 4500+ RPM. I thought the trans was blown out. I even called around for estimates.
At the time, the coolant was leaking onto the connectors on the shift solenoids.

I got the coolant leak fixed at the dealer for 1/2 hr labor ($48) and the trans has been wonderful ever since.
But please drain/fill the fluid with Honda fluid. I have been getting mine done every 20k miles or so.