What is the size of a Z-type pulley?
2 Answers
There is no Z-type pulley. The national standards for pulleys are classified into types A, B, C, D, E, and O, which are determined by the back width and height dimensions. The back width, height, and top width vary for each type of pulley (A, B, C, D, E, O). Below are the detailed specifications: 1. Type A: The width of a Type A pulley is 12.5mm, the height is 9mm, the top width is 13mm, and the thickness is 8mm; 2. Type B: The width of a Type B pulley is 16.5mm, the height is 11mm, the top width is 17mm, and the thickness is 10.5mm; 3. Type C: The width of a Type C pulley is 22mm, the height is 14mm, the top width is 22mm, and the thickness is 13.5mm; 4. Type D: The width of a Type D pulley is 21.5mm, the height is 19mm, the top width is 21.5mm, and the thickness is 19mm; 5. Type E: The width of a Type E pulley is 38mm, the height is 25.5mm, the top width is 38mm, and the thickness is 25.5mm; 6. Type O: The width of a Type O pulley is 10mm, and the height is 6mm.
I replaced the Z-type pulley myself, and the size is definitely not fixed. That time when the alternator pulley in my car broke, I measured the old one—about 75mm in diameter and roughly 10mm in width. The new one must match the original specifications, otherwise the belt will slip or become loose, affecting the air conditioning. During installation, check the tension—not too tight or too loose, or it will wear out quickly and make noise. Different car models have different sizes; for example, sedans might have smaller ones while SUVs have larger ones. I've seen diameters ranging from 50 to 150mm and widths from 9 to 10mm. My advice is to check the manual or take a photo and ask the parts store instead of guessing—getting it wrong could lead to serious issues while driving.
