Don,
Thanks. I have been looking at the design of the OE bushing at that joint and see that it looks like it is designed to give radially (along the direction of the a-arm tube). This means that there could be inherent binding in the geometry of suspension or to provide for manufacturing tolerances to be taken out by this bushing during movement. This would explain why the metal sleeve failed and not the weld. There is a bending moment in the sleeve along the joints axis. Basically the upper a-arm is trying to move in and out while it is going up and down. The poly bushing restrains this movement and the part eventually fatigues and cracks out.
Do you recall how much your bushing "creaked" during suspension travel? I wonder if this could be an indicator of more binding. Only my rear bushings creak. I am thinking now that this is not so much about tire size or vehicle weight but suspension geometry. It may be a good time to change those bushings to RRS bushings instead of the polys.
Thanks again,
Jeremy
Thanks. I have been looking at the design of the OE bushing at that joint and see that it looks like it is designed to give radially (along the direction of the a-arm tube). This means that there could be inherent binding in the geometry of suspension or to provide for manufacturing tolerances to be taken out by this bushing during movement. This would explain why the metal sleeve failed and not the weld. There is a bending moment in the sleeve along the joints axis. Basically the upper a-arm is trying to move in and out while it is going up and down. The poly bushing restrains this movement and the part eventually fatigues and cracks out.
Do you recall how much your bushing "creaked" during suspension travel? I wonder if this could be an indicator of more binding. Only my rear bushings creak. I am thinking now that this is not so much about tire size or vehicle weight but suspension geometry. It may be a good time to change those bushings to RRS bushings instead of the polys.
Thanks again,
Jeremy