I have a 98 Expedition with the E40D trans with 136K miles. The service manual says the trans has no regulary scheduled change of trans fluid. I'm taking a 5000 mile trip this summer and was wondering if I should abide by the service manual or change the fluid. I am having no problems. I've been told that chanigng the fluid could ceate problems. Any ideas?

 

There is NO fluid that lasts forever. Do your transmission a favor and change it. A proper service will not cause problems.