I bought a new timing belt and balance shaft belt from my local aftermaket parts store for my 1989 740 16v Well later I remembered that there was a manual belt tensioner, (my car) and an automatic belt tensioner and that each uses a different size belt. So I went back to the store to make sure I had the right one. Well the store's information says there is only one size belt for all years of the 16v engine, which I think is wrong.

So my question is; how figure out if I have the right belt in hand? The belt was purchased at a Carquest store and has a Carquest part # T173. From examing the box and belt I found it was manufactured by Goodyear in England. Other markings on the belt are 173, which I figure is a reference to the Carquest number, and 5 1 82DS which I figure is ether the Goodyear part # or some type of manufacture date code.

I anyone can help I'd sure appreciate it!