RACE 1T0474 - Caterpillar

(1) Poppet (2) Detent Balls (3) Upper Pin (4) Spring (5) Lower Pin (6) Block
Blocks - Look for wear on the inner and outer edges.
Detent Balls, Poppets, Upper & Lower Pins - Take care in not losing these small components, the detent balls will dislodge easily. Note any wear seen on the surfaces of these components.
Springs - Check for any flat spots or broken tips on the springs. Note any abnormalities. There is sometimes wear from the blocker ring on the springs (discoloration of the spring material).Wear Gap
Illustration 29 g03780982The wear gap is the amount of clearance between the blocker ring and clutch body ring when the friction components are pressed together. The clutch body ring must be placed on a horizontal surface. Use a feeler gauge to measure around the circumference several times until the friction components are centered and one reading is obtained all the way around. It is important that the components are pressed tightly to obtain an accurate reading. The synchronizer will be approaching end of life at 0.65 mm (0.026 inch). DO NOT REUSE the synchronizer if the wear gap is below 1.1 mm (0.043 inch) This is the most critical measurement of the entire synchronizer inspection!Single Cone Synchronizer
Illustration 30 g03780983
321-5765 Synchronizer Components
(1) Circle Clip
(2) Sliding Sleeve
(3) Poppet
(4) Upper Pin Ball
(5) Spring
(6) Synchro Hub
(7) Blocker / Friction Ring
(8) Clutch Body RingComponent Wear Inspection
Blocker Ring
Illustration 31 g03780984
Friction Material Wear- The friction material surface should appear rough with no glazing. The surface should feel granular and rough to the touch. Some material should come off on your fingers. If the friction material is smooth and shiny, the surface is glazed and synchronizer should NOT be used.
Tooth Flange Face- Tooth flange face should not show signs of scuffing / galling. Witness marks in this region indicate contact with the clutch body ring. Surface should appear black in color. If contact is made, DO NOT REUSE THIS SYNCHRONIZER (See Illustrations 6 and 7 for representative pictures)
Tooth Points - Surfaces of the chamfered tooth points should appear new and should not show signs of wear or change in shape. It is common for the heat treat coating (black layer) to be worn away and shiny, however there should be no measurable wear on the teeth. (See Illustration 8 for a representative picture.)Clutch Body Ring
Illustration 32 g03780985
Clutch Body Ring
Tooth Points - Surfaces of the chamfered tooth points should appear new. Some flattening of the tooth points are expected because the sliding sleeve has an internal stop that contacts the teeth upon engagement. OK to reuse the synchronizer in Illustration 32. If there are signs of tooth rounding