CAT OIL SIGHT GLASS includes gasket SUBJECT: Crankcase Cover and Threaded Style Oil Gauge The models 280, 290, 333, 430 and 10 Frame have all changed from the old pressed-in-style to the new threaded-in oil gauge. When replacing the old style crankcase cover with the new threaded hole style, it is necessary to use the new threaded oil gauge and o-ring. The threaded oil gauge PN 43214 has been superseded by a new bubble threaded style PN 43987. A new oil gauge removal tool PN 44050 is available for use with the new bubble threaded oil gauge.