big end bearings losing their tension

[garryt]

so done an engine swap over the weekend, and upon stripping the old one down I find the rod shells are loose what would be causing this??? no low oil pressure or strange noises prior to strip down. excessive oil temps or just high mileage maybe???

[Butcher]

I never really thought about it but I suspect the constant pounding on the bearing along with the heat allows the backing material to take a shape.

[garryt]

I guess so. that's the second 1.8 iv'e stripped down and found this. no sign of any damage, just the shells fell out very easily. I guess when they're torqued up they can't really go anywhere. will be getting new ones anyway if need be.