wingit

I am replacing the rear seal. I pulled the cap this afternoon and here is what I discovered.





The crankshaft isn't scared and it has a mirror finish. Trying not to panic I pulled the cap off between the 2nd and third cylinder and inspected that bearing. It looked perfect for 87,000 miles. How could this happen? Could dirt have gotten passed the seal and into the bearing somehow? Do I put this back on or try to replace the bottom half of the bearing? What are your thoughts. Jeep hasn't been burning any oil just leaking it.

landude

The crank doesn't look bad. I don't know what would be best practice for this.
I'm thinking replace it.
Wait for more input..

wingit

Well to replace just that half I would have to buy the whole crank bearing kit. $85.00

hankthetank

Just run it. The bearing material has to be softer than the crank surface to allow particle charging like you see. Its doing its job just fine by the looks of it. How many miles? Yours looks like mine did when I did the rms 2 years ago.

Programbo

My first thought was.....Are you SURE it was your rear main seal leaking? I think most everytime I met someone who was sure their rear main was leaking (Myself included!) it turned out the oil leak was actually coming from somewhere higher up (The oil filter adapter was the main culprit) and the oil then worked it's way down through small cracks and ledges on the engine until it dripped out at the lowest point which just happened to be the area right below the rear main seal where the engine and transmission meet.

wingit

Yeah, I here you. I had already replaced the valve cover gasket and after cleaning everything real good it looked like it was leaking on the drivers side of the pan gasket and the oil filter adapter. Since I was taking the pan off anyway I figured I would replace the seal and the oil pump while I was in there. I wasn't expecting to find the bearing like this. I replaced the oil filter adapter rings last weekend while doing this repair.

PDEM87

The bearings are made of a very soft material (babbet) and any particals that get past the oil filter get pumped to the bearings and can cause what you are seeing. If it was mine, I would test bearing clearance with plasti-gauge. If it passes, reinstall and switch to a better grade oil filter.

SeriousOffroad

I'd take a look at a few more, might be time to replace 'em all.

highmileage

^^ this...

bigbadon

No you wouldn't. You can buy individual bearings. And you would want to replace the top and the bottom insert. It is easy to roll in the upper half.

landude

Well, is it back together and leak free?
Details man...

wingit

I'm still cleaning and painting parts. Should have it back together and on the road Monday. I am going to check a couple more bearings though, just to be sure.

BlueRidgeMark

There's absolutely no point in replacing just the bottom half.

wingit

Okay, so I measured the bearing with plastigage and all but the center was in spec. Spec is 0.001-0.0025.





I'm going to check the neat bearing to this one and then I'm putting it all back together. I really appreciate the help guys!

mdo817

Mine was not that bad, but did have some galling in it when I did my RMS last year, I took some red scotch brite, just kind of of buffed the roughness down some, re-installed and torqued it up.