Would like to know what they do and about how much it will cost

 

Welcome to the forum "New Member" is a place to introduce yourself and your car but it's not a place to ask questions.

I understand it's your first post and you know what car you have but to answer your question we would need to know if it's 1968 P1800, 1994 850, 2010 XC90 or ............
4cyl with points, 5 cyl with electronic or even a diesel if you're in Europe, automatic, manual, 2wd, awd .....

120K service is different for different models and so is it's cost.

Please post your question in your cars proper sub forum.

 

What kind of car do you have?... And the timing belt is something that needs to be changed every 70000 miles .

 

No 70k was the interval for the early engines. They change it to the 105k then the 120k after that.

 

Being in Miamisburg you are relatively close to Tremaine's Volvo Service in Moraine. Sure beats paying dealer pricing.