Nissan Repair: what is an overdrive for?, nissan maxima, wrecking yard

Question
I am thinking about buying a 1990 Nissan Maxima,but they say the overdrive needs to be replaced.What is it for and how much does it take to replace it?


Answer
Tammy,

Overdrive saves you gas on the road by letting the engine run at a lower RPM.  If it is an automatic you have to get it fixed and if it is a manual and you do not do much highway driving it could be lived with.  However, either way you are looking at something like $1500 to $2000 in labor and parts to get it repaired unless you know someone at a wrecking yard that backs their parts.