What causes this excessive wear?

[RunninWild]

I finally got all my parts and began replacing the oil pump and main, rod and im shaft bearings in an attempt to fix my oil pressure issues.

The cause was pretty obvious after removing bearing cap #2


What causes the bearings to become so mangled like this? The crank feels smooth with one tiny ridge in the very middle (barely catches my finger nail) which I'm hoping wont be an issue for the new bearing. I'm going to check the clearances with plastigauge but I'm not removing the crank to do a proper inspection.

The other bearings were less severe looking more like this

I'm not sure if that big gash in the side happened before or after I removed it but I'm thinking it happened after it was removed. A couple of the other bearings had metal slivers coming off outside edges. Is this type of wear from oil starvation or some kind of other issue? I'm pretty skeptical of the supposed 175,000km this engine has.It starts and runs really well so at least it has decent compression. Even if the head is on its way out I have a brand new one sitting under my bed. I'm hoping the new bearings and oil pump will be enough to last it a few years.

The bearings are stamped 026 591B, google brings this up as vw main bearings but it doesn't list what size they are. Anyone know if they are standard size original bearings?

[thomas m]

Is the engine still in the car while you are doing this work?

I think not, since the intermediate shaft is involved.

[RunninWild]

It's in a Suzuki samurai which is a 4x4 so yes it's happening in car. I have a straight shot at the im shaft and lots of space to work. if I had it out I would have done more of an inspection/rebuild on the engine engine. Plus I would just get the crank inspected/ balanced.

[ORCoaster]

Holy Mackel Runnin Wild,

That level of wear seems excessive in my eye.  I replaced those parts in my 1981 and I found one to have looked something like that but in comparison the loss of the plating I had would make it look new compared to those on yours.  Is the crank all scuffed up as well then?  Just putting in new smooth parts around a rough surface will just cause it to wear again. 

Only one of my caps looked damaged.  And I owe that to the cap coming loose and spinning one over the other. 

So as for a suspected cause I would have to lean towards no oil pressure.  Or very badly contaminated oil.  There isn't a lot of flow between those parts that I can tell so once a shaving of coating of the metal comes off it seems to stay there and cause more problems.

Be sure to pre lube those places on the cap and crank or they will be dry when you first try to fire it up and you may be recreating this very condition you are trying to cure.

[RunninWild]

The crank feels alright just a tiny ridge in the very middle of the bearing surface and you can barely feel it with your finger nail. Visually It definitely looks a bit scuffed but it feels more or less smooth to the touch other then that one ridge only on the one surface.  I'm going to just go with it for now. If oil pressure drops again then I'll just pull the engine and rebuild the block.

I guess the 0 oil pressure at idle caused quite a bit of damage. I drove it for maybe 300km before I installed my oil gauge and realized the issue. I guess the original guy that pulled the engine was a bit dishonest in its condition. People suck!

[RunninWild]

I had about an hour and a half to work on it today before it got too dark. Progress is slow as this is my first time doing any engine work beyond a head gasket, but I'm taking my time and trying to do it right and as clean as possible. I plastigauged the first rod and it came in at .02mm which is in spec from what ive found online (.01mm-.03mm). I didnt bother doing the other 3 as there was no abnomal wear on the crank or the bearings and Its hard to access everything as there isnt much clearance above my axle and the engine.
The good news is the rod bearings looked to be in great shape! None of them showed any extreme wear like the main bearings they all looked more of less like this, I was able to get all 4 of them replaced


I'm having a bit of trouble getting the main bearings installed, I'm having trouble getting the upper bearings started between the journal and the bearing seat. The one i'm working on came out easy enough rolling it out with a cotter pin. Should I try and loosen all of the main bearing caps and see if the crank drops a little?

The oil pump bushing feels nice and smooth, Ive read these dont necessarily wear very badly. Should I bother replacing it? I bought one just in case but It might be better to hold onto?

Anyone have any idea how the rod bearings were in such good shape in comparison to the mains? I would think they would wear more or less at the same speed, if anything the rods first as they get their oil after the mains correct?

[Jetmugg]

My 2 cents - it's worth the extra effort to remove the engine from the vehicle so you can do this work in a more controlled manner.  Am I reading your post correctly that you are trying to "slip" the bearings in between the crank and the block with the crankshaft still in place???

Steve.

[RunninWild]

Yes that's correct. I've seen videos online and read a lot of guides that it's possible to do so. I don't have a hoist so pulling the engine isn't an option at this time.

I'm just gonna loosen all the main caps and try and drop the crank enough to fit in the bearings.

[RunninWild]

Made some more progress. Its slow going as I don't have much daylight by the time I get to my truck after work. I have all the bearings and caps in finger right now. Loosening all the caps was enough to make rolling in the new bearings a breeze. I have to swap one of the lower bearings as the one with the 360 degree oil channel apparently goes in the number 4 bearing and not the number 3 like I assumed

Also just so its out there if anyone was wondering the 45mm rod bolts do work in the older style  rods that originally had 43mm bolts, and the ARP studs for the ALH also work in the older aaz block that had shorter main bolts as well. The difference in size is pretty insignificant but I couldnt find any definite answers online about compatibility between the two styles.

[RunninWild]

New bearings in currently idling at 177f oil temp and 15psi at the head. Huge improvement. Im assuming this is sufficient pressure. Havnt test drove it but revving the engine easily brings the pressure to 45psi+ I don't have a tach so no idea on rpm but I'd guess 3500-4000...

[ORCoaster]

Oil pressure at that temp is good.  If you see it bump up on idle that is correct behavior.  Hopefully you will see better mileage out of the fuel you use as you are not grinding on one piston anymore. 

Glad it worked out for you.

[RunninWild]

I swear something doesn't want me to drive this truck. Filled the tires and was about to go for a test drive and no brake pedal . Look under the hood to find an empty master cylinder, all the brakes are clean and no puddles anywhere so thinking it leaked into the booster. Cant catch a break with this thing lol.


As for fuel mileage I dont really have a baseline. I havnt been able to put more then 2 tanks of fuel into the 2 diesels engines I've put in this truck in the past year. I'll just be happy to drive the thing but knowing my luck something else will break as soon as I fix the brakes.

[ORCoaster]

Sorry to see that followup.  I makes me think of all these Craigslist ads I see from time to time.  They have a huge list of items that have been recently replaced and somewhere in the description you read that they are just fed up with this thing breaking all the time.  Then I know that folks have purchased said vehicle, fixed that broken item and have been free from breakdown for years afterwards.

Just keep at it.  Someday it will be worth it.  You can sit back and know all your work and labors paid off and now you can just drive it worry free.  Or maybe not.  You might just be waiting for the next part to go kaput. 

[RunninWild]

Lol yeah. I'm planning upgrades to replace practically every part on the truck so it'll eventually be good.

Assuming the wear on the crank doesn't chew up the new bearings within a few weeks it should be ok to drive for a while once i get the brakes sorted.

[Toby]

The bearing damage is caused by lack of oil. You were probably just minutes from catastrophic failure. It would be best to polish the journals before you put the new bearings in, but that can be problematic with the engine in the car. It is of paramount importance to make sure that you flush ALL of the grit and flotsum and jetsum out of the oiling system and crankcase before you light it off or the bearings will be damaged at initial start up. Use the softest bearings that you can find when doing an "in chassis" repair like this. A soft bearing will embed any particles that get into the space between bearing and journal. This will push up a little crater of bearing material and prevent the grit from touching/damaging the crank. Hard bearings like CL-77s will cause the crank to be scored by the same particle. Hard bearings like CL-77s (tri-metal) will take a lot more abuse and have a longer service life, but require very clean oil to reap those benefits.