wr 426 piston worry
Posted January 09, 2016 - 08:55 AM
Posted January 09, 2016 - 09:06 AM
Posted January 09, 2016 - 09:16 AM
Roundness at the top of the crown isn't an important issue, as the ring lands, the area from the crown edge to below the oil rings is cut back smaller than the skirt, and is not in contact with the cylinder under any normal condition. Note that any indication of the ring lands having run against the cylinder is evidence that the piston is worn out. What needs to be carefully checked is the piston to bore clearance.
The damage doesn't look bad enough to worry about, but you also need to check the clearance the top ring has in the groove near the damaged area compared with the rest of the ring groove to see if the ring has been pinched.
Posted January 09, 2016 - 09:47 AM
Posted January 09, 2016 - 10:02 AM
Posted January 09, 2016 - 10:39 AM
The first thing here is to find a magnet and see whether the bulk of those chips are steel or aluminum. If there are a bunch of more ore less uniform, squarish looking steel chips in the oil, it usually means there is a failing bearing in the assembly that is shedding metal chips (spalling) from a race or some of the balls.
Aluminum from the clutch should be more in a "splinter" form. Small filings of aluminum may indicate that something has come into contact with one of the cases internally.
How long has the filter been in service?
Posted January 10, 2016 - 12:24 AM
Posted January 10, 2016 - 09:53 AM
Posted January 10, 2016 - 11:42 AM
Check for verticle freeplay, there should be none at all.
Posted January 10, 2016 - 11:47 AM