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Inside Snap Ring U-Joint Identifier

 Inside Snap Ring Style U-Joint

Inside U-joint snap ring guide
End yoke inside Snap Ring Measuring Guide

Width: 
If measuring the ujoint, measure the distance to the outer edge of the snap ring grooves. If measuring the end yoke, measure from the inside flat of one yoke ear to the inside flat of the other ear.

Cap Diameter:
If measuring the ujoint, simply measure the ujoint cap.  If you are measuring the end yoke, measure the width of the opening where the cap sits in the yoke.

 Common  Inside Snap Ring U-joint Sizes and Series

 Series Width Cap Diameter.
7260 Chrysler 2 -  (2.125) 1 -  (1.078)
7290 Chrysler 2 -  (2.625) 1 -  (1.125)
3R GM  2 -  (2.563) 1 -  (1.125)
2R GM  2.342 1.00