1990 Dakota 2x4 3.9 long bed. When driving around town, to and from work,The trans dosn't act up at all...but the first long trip I took with it (200-250 mi. ) the truck started to fail to up-shift? I only bought the truck a month ago and this was the first long drive with it. NOW I know the radiator is almost shot by the lack of fins. I do have a new one but just haven't gotten around to change it. Could it be that the radiator is OK for cooling around town but on long trips its not getting enough fluid to the trans, on long runs?? After arriving home and setting over night the trans works fine again.Also the truck has not over heated even on the long trip.Could my finless radiator be related to the trans problem?

 

since it is not overheating hard to say. since you have a radiator on hand i would swap it and see if still have tranny issue if it does not help then i would flush the tranny, not just a filter and the fluid in the tranny pan but a full flush.

 

Yes I will put the radiator in and see if that helps.(I hope) .The tranny fluid is cheery red, but if the radiator dosen't help I try that next. any Idea what a complete flush costs with new filter?Thanks

 

maybe could get it for $125.

 

Thanks Bob