Over the last week My 98 Durango Transmission has started acting funny, every morning on my way to work it will not shift into overdrive, and it is no fun driving on the interstate at 70 mph running like 4000 rpms. After about 10 minutes it will finally shift into overdrive. Any ideas why this just started happening?

 

Could be a band adjustment needed. Take it to a shop and get the fluid, filter, and also the bands adjusted.

Other problems could be a hung up sensor, bad govenor sensor, or a linkage adjustment.

 

if you problem is an excessivly delayed overdrive shift, then you should have your sensors checked and then have a tranny shop look at the overdrive piston bearing spacer. these 2 things are the most common causes of delayed overdrive shift.

 

oh and just a note, there are 2 bands in your tranny a front and a rear. the front band is only applied while you are in second gear in the drive mode and in manual second, and the rear band is only used in reverse and manual first gear.
so you may want to have them adjusted, it wouldn't hurt but they have nothing to do with the overdive problem.

 

The overdrive doesn't have a band adjustment. But problem could be a lip seal on the direct piston, or temp related.