Well the JGC is down for repairs. I was hearing a pretty loud tick on the way home so I pulled the valve cover and checked the push rods and upper valve train. I even held each push rod while vehicle was running and no difference in sound. The next step was to drop the oil pan. So I did and found piece of a piston skirt in there. It was from the #6 cylinder. Well I checked the bore and no signs of damage. Guess it's time to take her apart. 187k miles. Gotta find torque specs., and a decent 12pt. 13mm deep impact socket for the head bolts. Wish me luck.
I pulled the head off and pushed the pistons out today. only #6 piston skirt was broken. The cylinders are all clean and shiny and the crank has no marks. Thanks for the link to the torque specs ChrisHager, they will come in handy. My rods have the stamped #691 on them. Well time to look at these companies to see who has the right piston and rod set for me. There are a couple of different ring thickness for the pistons. Is there a difference. Time for some more research.
Shouldn't be ring thickness. Those measurements of the new rings are how oversized you want them. Standard is for a standard bore and they usually go up in .020" increments determined by how much you would bore the cylinders out in a complete rebuild. If you are positive the motor has never been completely gone through, just order the standard size rings and pistons. If you have any doubt, measure the bores and compare them to what they should be stock and order rings accordingly. The same thing with big end of the rod and crank journals for rod bearing sizes.
I used Sealed Power pistons and rings on both of my rebuilds. They have the thicker skirts. I bought them through the machine shop that bored my blocks and I had them install new camshaft bearings in both blocks. The wristpins have to be pressed out and pressed back into the rods. I had them do that too. Is the rod damaged? The machine shop redid my rod journals too.
So sealed power makes 2 different pistons for apparently the same application. Sealed power H802CP or H825CP should be a exact replacement for the piston that I was looking for. But it depended on the size of the rings I have. Its just the regular cast hypereutectic piston. On the H802CP, ring 1 and 2 is 1.5mm and ring 3 (oil ring) is 4.0 mm. On the H825CP, ring 1 and 2 is 5/64 and ring 3 (oil ring) is 3/16. One is standard and one is metric. That's just how it is listed. I had to look for the part number on the inside of my piston and the H802CP is a cross reference of 53020507. The H825CP is a cross reference of 4798329. Mine happened to be 53020507. Hopes this helps someone out in the future.
Watching the thread... XJ guy here but I just pulled the pistons out of a 99 WJ we bought for my wife. The cylinders were not bad (Did a quick hone and they look okay), but the piston skirts were pretty scuffed up. I am thinking of just putting in a new set, since I am here... The Jeep had a terrible knock when we bought it...
I pulled all the rod caps off and the bearings in them looked fine, but when I pulled the pistons out, the top half of the bearing in every rod was showing copper.... so I will put in a set of rod bearings.
The bottom half of all the main bearings looked fine, but I think that as long as I am here (& since I couldn't check the top half of the bearings), I will do the main bearings & rear main seal as well.
Who do you guys like for bearings & gaskets? I know rock auto has 'em, but are there brands to stay away from? Which brands offer the best value?
TMA MN State Rep