Alright, well i don’t usually do this. Yet my Father and myself are baffled on this one.
1998 Chevrolet S10 2wd extended cab
2-piece 5 u-joint drive shaft
customer came in with a vibration. 2 rear u-joints were seized. i changed them.
customer took the truck. came back today with a moaning and a very slight vibration. i took it for a drive as did my father. it’s an acceleration moan/slight vibration
double checked the drive shaft and hangar bearing today. no fault found. i ripped the rear end apart and carefully went through the bearing, spider gears, posi unit, and double checked pre-load and back lash. everything is perfect.
not necessarily ruling out the rear and and drive shaft. but i don’t think that is the problem. motor mounts and trans mount are in good shape. clutch fan is not seized. although seems to have minor play on the water pump. removed the clutch fan. took truck for drive. still there. removed belt. took truck for drive. vibration gone.
assuming it’s the water pump now? the tensioner and pulleys are good. the water pump has no play what so ever.
it’s not the balance shaft in the motor. if it was it would be constant. harmonic balancer is in tact.
any information or suggestions would be great. we are leaning towards the w.p but want to be 100% sure before we replace it.
sorry for the long post.