Series

The "series" of a driveshaft or universal joint is determined by the actual dimensions of the u-joint. While the front and rear u-joint can be of two different sizes the shaft is only as strong as the smaller one. The 1310 series u-joint measures approximately 3 1/4 inches wide. The 1330 and 1350 both measure approximately 3 5/8 wide. The 1310 and 1330 series can have cap diameters of 1 1/16 and/or 1 1/8 inch or a combination of both sizes. The 1350 series has a cap diameter of 1 3/16 inch and the body and journals are bigger than the 1310 or 1330. Remember 1350 is almost never found in production car driveshafts.

It is always a good choice to upgrade to the 1350 series components whenever your application is used for racing or with high horsepower and street use. Stock driveshafts were designed to handle a modest amount of horsepower. If your application has more than 400 horsepower then its time to consider a new shaft.

The 7260 and 7290 series are the two sizes that are commonly found on Chrysler products. They represent the two stock sizes that have been used for many years. The 7260 series is the “small” Chrysler u-joint size (2 1/8 inch between flats on yoke with 1.078 inch bearing cap diameter) and the 7290 series is the “big” Chrysler u-joint size (2 5/8 inch between flats on yoke with 1.125 inch bearing cap diameter). The 7260 series is similar in size to the 1310 series and the 7290 is similar in size to the 1330 series. They both utilize the inside “C” clip design to hold the u-joint within the yoke flats whereas the 1310 and 1330 use the outside snap ring design.

General Motors typical u-joint size found on most passenger cars and light trucks is commonly know by a few names. They may be referred to as “3R” or “Saginaw” but they are all one in the same. Depending on who is doing the talking you may hear any one of these terms. The 3R series measures 2 9/16 inches between flats on yoke with a 1.125 bearing cap diameter. The factory original u-joints are held into the yokes by injected plastic. This u-joint is similar in size to the 1330 series. The replacement u-joints utilize the inside “C” clip design to hold the u-joint between flats within the yoke whereas the 1330 series uses the outside snap ring design. You should be extremely careful not to heat the plastic with a torch to remove the original u-joints because the heated plastic will emit toxic fumes that are not good for your health.