Would it hurt to drive about 40 miles and back on the freeway with a transmission that smokes? It has been doing this for a while and I still can't find out why it is doing the smoking. Thanks

 

About the only way a transmission will smoke is if trans fluid is leaking onto the exhaust somewhere. This could be almost anything - overfilled trans, leaky dipstick seal, loose cooler line, or bad front or rear seal. Check the fluid level frequently. Also, there is a very small but non-zero chance that the leaking trans oil can catch fire on the exhaust.

 

My guess is that it is a seal of some type. The smoke rises from the area at the base of the dip stick.