What causes a crankshaft thrust bearing to fail?
What causes a crankshaft thrust bearing to fail?
Naturally, improper assembly—se- lecting the wrong thrust bearing thick- ness, contamination during assembly, etc.—can lead directly to thrust bearing failure. In general, though, one or more associated problems are usually to blame, including poor crankshaft sur- face finish, bearing overloading or bear- ing surface misalignment.
What should the thrust surface be on a crankshaft?
Finally, following the above procedures with care should; maintain a thrust surface that is 90° to the crankshaft centerline. Tighten main cap bolts to approximately 10 to 15 ft.lb. to seat bearings; then loosen. Tap main cap toward rear of engine, with a soft faced hammer. Tighten main cap bolts, finger tight.
Where are the thrust bearing slivers on a crank?
The crank- shaft was ruined to the point of not being economically re- pairable, resulting in the purchase of a new crank. Slivers of bearing material and crank thrust flange surface were found throughout the bottom-end and sump. The crankshaft rear thrust flange was also worn down severely to a knife-edge. 30 August 2010 Photos: Mike Mavrigian
Where is the thrust bearing on a small block engine?
All Ford engines and the new generation LS small-block place the thrust bearing in the center main cap, which may be an advantage under high load conditions to stabilize the crankshaft. It’s best to sand only the leading edge side of the thrust bearing when increasing clearance.
Finally, following the above procedures with care should; maintain a thrust surface that is 90° to the crankshaft centerline. Tighten main cap bolts to approximately 10 to 15 ft.lb. to seat bearings; then loosen. Tap main cap toward rear of engine, with a soft faced hammer. Tighten main cap bolts, finger tight.
What should I do if my crankshaft is not working?
Tap main cap toward rear of engine, with a soft faced hammer. Tighten main cap bolts, finger tight. Using a bar, force the crankshaft as far forward in the block as possible; to align the bearing rear thrust faces. While holding shaft in forward position, tighten main cap bolts to 10 to 15 ft. lbs.
Where is the thrust located in a crank endplay engine?
This makes crank endplay a spec that cannot be overlooked, and that alone should motivate all but the laziest of engine builders. We will be using both a small- and big-block Chevy for the images in this story, but the process is the same for all engines even when the thrust is located in the center main bearing as with Fords and the GM LS.
The crank- shaft was ruined to the point of not being economically re- pairable, resulting in the purchase of a new crank. Slivers of bearing material and crank thrust flange surface were found throughout the bottom-end and sump. The crankshaft rear thrust flange was also worn down severely to a knife-edge. 30 August 2010 Photos: Mike Mavrigian
