rod bearings failed less than 5000 miles?

[mitecl96]

Well I was heading to my grandma's house about a 20 min drive. On the way I started to hear a knock a mile from her house. Coasted to here house and got to listening. Was for sure it was the rod bearing. Towed it to my house pulled the oil pan. Sure enough Evey connecting rod was loss on the crank and had play.

My car was never hot roded. Always had oil and never had a tick or knock since the rebuild 5,000 miles ago.

Here is one of the bearings. To me it looks like a bent or distorted crank. What do you guys think?

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[92AWDHX40]

Those look bad what brand are they, and who did the install, any material in the bearing, contaimnation such as media, or dirt, was the crankshaft inspected for damage or polished, was it miced, did you have it plastigauged, or just dropped in.

 

[grothe3297venge]

^^^^ concur, did you have the crank spec'd before you threw new bearings on? Also what procedure did you follow when installing them, assuming from your street build you installed them yourself.

 

[mitecl96]

They are King bearings.

Yes I did install them. Everything was clean properly.

The crank had the mains polished and the rods were resized to .5. The machine shop check the bearing sizes for me before I got the bearings. They told me the mains had already been turned once and was also .5.

Everything was put together with assembly lube. Everything was torqued correctly and rechecked 3 times before I did the 1/4 turn without using the torque wrench.

 

[92AWDHX40]

Well time for some new ones try some oem ones.

 

[grothe3297venge]

Do you have any pics of the crank, curious to see how it also looks.

 

[mitecl96]

Idk because to me they look like a bent crank from the bearing failure analysis chart I looked at.

I had talked to the company I bought the kit from and they seem to be helpful they asked for pictures yo send to King.

They should be getting back to me soon this week.

Do you have any pics of the crank, curious to see how it also looks.

They crank looks fine I couldn't see any scaring but it's still in the engine. The engine is still in the car.

 

[mitecl96]

Anyone else have any idea? Really want to figure out the cause to know what needs to be done

 

[91fwdnightmare]

A bad bearing meterial can also cause premi failure if the rods were to tight would also cause it
Theres a few things that can cause bearing failure, before condeming the crankshaft to the bent side of the moon id check all clearences. If that cranks isnt scared on one side or the next than id be getting a clevitte bearing set put it back together toss a manual oil pump gauge on it and see where your at.

 

[silvreclips]

You should have also plastigaged the bearings when you put them in to verify bearing clearance.

 

[mitecl96]

A bad bearing meterial can also cause premi failure if the rods were to tight would also cause it
Theres a few things that can cause bearing failure, before condeming the crankshaft to the bent side of the moon id check all clearences. If that cranks isnt scared on one side or the next than id be getting a clevitte bearing set put it back together toss a manual oil pump gauge on it and see where your at.

Everything was torqued to spec. I know there is more than one thing to cause bearing failure. I went here
http://www.wilmink.nl/Clevite/Clevite_lagerschade_tech_info.pdf
and compared my bearings and the only one it looks 100% like is the bent or distorted crank, that is why I was asking that.

Also what do you mean "if the crank isn't scared on one side or the next" Right now that isn't making since to me. Are you saying just throw new bearings in it.

You should have also plastigaged the bearings when you put them in to verify bearing clearance.

I didn't plasigauge because a few people on her said it was a waste of time and if the machine shop said I needed this size bearing that it would be the right size. Of course after the engine fails everyone says I should have. I just went with what the machine shop said, I had them tell me the bearing size on 2 different visits by two different guys.

 

[iceman510]

and the rods were resized to .5.

All of the wear (the dark spots) are in the thrust direction. The statement above concerns me. When the rods are resized, that means they are cut to the original specification to ensure proper sizing and roundness (which includes surfacing the cap and then rehoning). They should not be changed in size to accomodate a cut crank. That dimensional difference is accounted for in the bearing itself. Better have the rods rechecked for dimension of the big end.

 

[YanDsm]

Plastigauge isn't really not a waste of time, it took me about 10 min to do and now i'm sure that my clearances are good in my engine.

 

[mitecl96]

All of the wear (the dark spots) are in the thrust direction. The statement above concerns me. When the rods are resized, that means they are cut to the original specification to ensure proper sizing and roundness (which includes surfacing the cap and then rehoning). They should not be changed in size to accomodate a cut crank. That dimensional difference is accounted for in the bearing itself. Better have the rods rechecked for dimension of the big end.

You misunderstood that. The crank was resized. not the rods them self. The rods in my car couldn't be reshaped due to they are fracture split and can only be oversized. I had two rods but I just went and bought 2 oem rods.

Plastigauge isn't really not a waste of time, it took me about 10 min to do and now i'm sure that my clearances are good in my engine.

Well if I wasn't told that it was a waste of time I would have done it. but to late now.



I just looked up bearing failures again and see that I misunderstood the page and those are main bearings not rod bearings. Got into farther searching and starting to look like a Overlay fatigue, maybe? what causes this.

 

[donniekak]

When the crank was cut, were the oil galley balls pulled, to clean behind them?

 

[mitecl96]

When the crank was cut, were the oil galley balls pulled, to clean behind them?

Is that something I have to tell them to do and does the machine shop do it.

 

[92AWDHX40]

When having machine work done always ask questions do some research firsts to save problems like this in the future.

 

[BogusSVO]

Is that something I have to tell them to do and does the machine shop do it.

Depends on the shop.... Most will not unless you ask, even then some will say its a waste of time to do.

I can not recall what a 420a crank looks like or if they have the oil galley balls to be removed.

 

[91fwdnightmare]

if I remember rightly they make a .002 bearing for that cracked rod that allows you to have them cut and resized... the machine shop should have been able to find them otherwise that could be your hole issue. cb1788b is the part number for those bearing sets available in .010's and .020's
as far as what I was meaning with scaring on one side of the crank or the other is rotate the crankshaft with a light looking at the surface to check for any grooves or anything out of the normal

 

[mitecl96]

if I remember rightly they make a .002 bearing for that cracked rod that allows you to have them cut and resized... the machine shop should have been able to find them otherwise that could be your hole issue. cb1788b is the part number for those bearing sets available in .010's and .020's
as far as what I was meaning with scaring on one side of the crank or the other is rotate the crankshaft with a light looking at the surface to check for any grooves or anything out of the normal

.010 was the rod and mains. On the crank. Got mixed up in the size. But the bearings were the right size from what the machine shop said.

The crank is fine to my eye.

 

[91fwdnightmare]

While it was all apart did they check straightness of the crankshaft? Either way i hate to be that guy but you should pull it and go through it.

 

[mitecl96]

While it was all apart did they check straightness of the crankshaft? Either way i hate to be that guy but you should pull it and go through it.

They had the crank and said it was good to go in. I don't think they would be able to turn it correctly if it was bent.

I don't know it I'm even going tl fix this engine. Just really want to know what went wrong with my first rebuild

 

[killercolt]

Please tell us what the your bottom end components are.

If you had the crank grind, the are suppose to be able to index the crank onto the machine to check for straightness. Afterward, they are suppose to check for round out. If the machinist had too much moonshine, he might not check it like he should.


Did you clean out the oil journal correctly?

 

[staztrx250]

Bet they were eagle rods, and the were out of round on the big end.

 

[mitecl96]

When they called me when they had the crank they told me the the mains were once cut and just needed polished. The rod were scared and needed cut one size smaller. They then said everything else was OK.

I cleaned everything right with water and air.

They were stoke OEM rods.