Big Block Bearing inspection...

[RanchWelder]

My new Big Block Chevy engine has been diagnosed with a bad oil pump. (***Trans was working great when it was taken off the road... 4L80E vs 10.5 FF 14-B).
Hoping to change the oil pump/pickup and verify the rod and main bearings for damage/wear, while engine remains in the truck.

It's either a 1999 or 2001 K2500 Suburban... but the engine mains are similar or the same for both bottom ends... (YTBD...)

(If it's the 8.1L, all ready set to handle the crank sensor mod, while under there... if it can be wedged out in pieces and replaced...)

With respect to crank bearing measurements and inspection while on the truck, what do you guys have for advice for me, while oil is dripping in my face, removing one bearing cap at a time?

Will be using a new Fowler Micrometer Engine Bore Gauge set, a new six piece outside micrometer set: 0"-6" .0001", and a good used 6" Digital Caliper...
(Hoping to avoid plastigauge...)

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The BatCat is inspecting the tools... he'll be holding the camera later on... BatCatCam...

1) (a) What kind of wear numbers can I expect from an engine with 180-200K miles on bearing wear? (Exact mileage to be determined...)
(b) What range is acceptable and when does it need to be swapped with a different size bearing?
2) What is the best procedure for measuring with the Fowler set?
3) Can this be performed pulling one cap at a time, or mains first, then rods and in what order?
4) Can I replace them all, if suggested, using this method, without screwing up end play? How do I verify end play with everything still in the truck, if it needs to be verified?
5) Can the job be performed without a piston falling out in my face? How should I prevent this from happening?
(If it happens, can it be put back in from underneath and/or how tough is it to do, without a spring compressor?)
5) Do I need to replace the rod bolts and main bolts, before this gets started? Can I reuse the stock bolts, so long as they are in the exact same location?
(If not, and I can avoid buying stretch bolts, what style/brand works well for stock rods and upgrades the bottom end for strength and retains balance?)
6) With the caps on rods/mains, what is recommended for torque during measuring? Can I reuse the old bolts for this step, or do I have to use the new ones, if required?
7) Is the high volume pump a worthwhile upgrade, considering the original pump failed? (*Will it require a deep screen intake... see question number 9).
8) How will I know, without removing the camshaft, if there may be cam bearing wear?
(Can it be determined via pressure readings after the bottom end is redone?)
9) Should I be looking into a deep pan with a baffle, so the pump does not run dry at 5%-8% grade, where I live and drive?
(If suggested... Does anybody have a good used Deep Big Block Chevy pan for sale? I can weld in the baffles, if it does not have any.)
10) Is there a way to gauge stretch/wear on the timing chain, check if it is worn out? (Planning to upgrade this at a future date.)

Hoping to get enough advice so this engine can be saved...
The number of o-rings and line disconnect tools and replacement clips/retainers to be replaced on any modern Big Block is daunting.
Kind of a nerd when it comes to making certain the o-rings are good everywhere...
The truck has been sitting for 3 years. Pictures posted when available...

If this thread has to be moved because it is a newer engine/vehicle, please let me know...
I'll be primarily taking/posting pictures of the Bottom End/Bearing Inspection/Replacement process.
Hopefully, others will learn what you guys suggest be performed... as the best ideas get hashed out by the professionals, who may generously offer their time to guide this repair.

Pictures of your used examples of crankshaft and bearings would be great, so we can compare the wear and measuring process vs what's under my pan...
To be continued...

 

[Bextreme04]

You can’t use that type of gauge to measure anything with the engine in place. How do you know the pump failed? Did they try to turn the pump with a priming tool and measure pressure with a mechanical gauge? The bearings are not the same in a Gen VI BBC and any other Gen. The 8.1 is also different. For a Gen VI, you will need Chevrolet performance #1 and #5 bearings to get the correct stock clearance. The rest are identical to Mark IV and Gen V BBC.

I would first verify that the pump is not working, then check to see if it was just due to the shaft collar breaking(they are plastic). Then I would pull the pan to replace the pump and inspect the mains and rod journals to see if they are discolored from extra heat. If you pull them apart, you might as well just replace the bearings(rod and mains) and then just inspect for scarring or discoloration. If no scarring or discoloration, then slip the new bearings in and torque it all back to factory specs.

 

[Ricko1966]

Lots of questions I will try to remember them all and answer them to the best of my abilities.High volume oil pump I do not like them and think they are unnecessary,they require more power to operate,and increase the chances of sucking the pan dry. I am unaware if your engine has stretch bolts on the rods and or mains. I have reused thousands,that is not an exaggeration,literally thousands ,of one use only rod bolts,and I've never seen mains you couldn't reuse,but I was already working with engines that I knew I could get away with this. Cam bearings turn at 1/2 crank speed unless there is a bunch of trash in the pan,I wouldn't worry about the cam bearings. The main bearings and rod bearings can be changed from underneath NBD,there is a little trick to doing mains, put a cotter pin in a journal oil hole with the loop end sticking out,turn the crank and let the cotter pin push the bearing shell out,push the new one. back in the same way,Be sure to look at your tabs so you know which way to turn. Boy I'm going to send everyone into orbit here,if my bearings look good,that's my check, if you've got any bearings that show evidence of pounding,it's game over,right now.The engine comes out and comes apart so the big ends of the rods can be checked or resized and the mains can be checked and line bore if necessary. As for checking clearances on a used engine if I'm on my back just putting bearings in. I buy name brand,I verify what bearings were in it. I put the same size back in and call it a day I've never measured my rod big ends or crank journals on a bearings only ,in car situation just a thorough visual on the bearings,the crank,the rod big end bores ,and the main cap inside,you are looking for missing cross hatch from when the rods and main journals were sized and I run my thumbnail across the crank journals. I've never been in an engine that you could pull a piston out of the bottom so no they will not hit you in the face, you will want to put 3 inch long sections of fuel hose over the rod bolts when you are putting the rods back on the crank,I don't, but you should,it keeps the rod bolts from hitting the crank. Yes this can be done 1 journal at a time. I'm going to try give you the best method without special tools and try not to confuse you. With the plugs out tuning the crank by hand you feel a point where the crank just feels loose,no resistance stick a pry bar between the harmonic balancer and what ever you can find to put pressure on the harmonic balancer to push the crank to the rear as far as it will easily push,making the jig to do this with feeler gauges is to tough. So get a dial indicator mount it where ever you can to take a reading on how far the the flywheel moves when you pry the balancer back forward. You aren't trying to force it or check how far it deflects just get it take out the clearance in each direction. That's all I remember.,from your post I probably missed a couple of things. Sorry

 

[RanchWelder]

OK... the truck is not here yet... the owner is in Key West laying on the beach!
Good for Him!

So far it sounds like checking for the plastic rod connector parts in the oil should be obvious... point of failure... Check

No need for high volume... check.
Cam bearings run half speed... check.
Was looking at Clevite-H series, They come with one big main bearing and 4 rod bearings, so I need 2 sets right? $200-$240
Ditch the Fowler for anything here, because the crank should never be out in order to use it... Copy.

Yes I do own an oil pump priming tool...

When I rebuilt my 355 I used the GM Performance rod and saved the old rod and plastic connector, from my low milage small block. It was likely Chevy Performance also, everything else on the engine was...

Which ever rod is in it may or may not match length, but the plastic connector might...
Man would it be cool if that's all was wrong...

If the plastic connector shattered, then I might have to clean the distributor bushings for oil baked on the shaft there too... The truck was used for plowing for 2 years... Generally, we get a foot or two a year, but three years ago we got walloped and that's when I'm guessing this broke down. IDK... we'll soon see...

Agree with finding what size and match them, there must be several styles of grinding a crank and selecting bearings and I do not want to learn every one of them now, just to get running again.

Rod wear or missing cross hatching means trouble... Check
Perhaps I should check them all before I buy any new anything... in case of the bad scenario...

Re-use the rod Bolts and possibly the Mains... Check
I read today the Gen VI and VII big blocks do not use one-use rod bolts...

After what you said Ricko... it probably make sense I get used to the idea of just reusing them so I don't ruin the balance.

Without machining and sizing the rods... with the exact bolts in place, I read the caps and bearings will walk using new hardware?

I'll try to buy a couple of paint pens so I can ID the bolts red vs white as I remove 2 at a time, so they don't get swapped.

Millodon Main bolts are $204, the studs are $178... Guess I'm reusing the main bolts...
Maybe I can afford Nord-Locks on them though...

My 1/2" torque wrench is the Blue Handle bar style and brand new.

Have a gauge to check pressure however I have no idea which engine it is for certain, so I'll have to suss out where to tap for pressure readings when it gets here.
Would think the truck gauge could be wrong... who knows, probably best to use a different gauge to be certain.

My thinking is "always change the oil pump"... file, mill and polish the new gears, polish and port the flow with my Carbide AirCat Mill, buy a new copper gasket and test the pump prior to install running on a drill in a bucket of oil? ...just brainstorming...
Read recently about failed pumps right out of the box... Brrrrr..

This is what I have for an indicator:

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There's an old magnet version somewhere in the shop on a shelf, I saved from the rodent infestation of a very old tool box... I can use, if this won't work.

Ricko1966 there's common sense in your comments... no sense in making it overly complicated, pull them out, verify the size and replace them all if there's no damage.

Really want to see the hair pin you are talking about... I get it, slide it in and rotate so it uses the oil hold to rotate out... Check... no scratchy scratchy..

I'm still a bit cornfused regarding the crank end play measurement you indicated I do...
We can get into that as it become evident... I'm thinking you mean verify what you have and plan to put it back the same? Or there's more to set up that I'll need to learn...

So I'll bump this thread when I can answer the questions you and Bextreme04 have asked.​

a Gen VI, you will need Chevrolet performance #1 and #5 bearings to get the correct stock clearance. The rest are identical to Mark IV and Gen V BBC.

This ^^^ is why I shouted out for help... Without this engine's manual, I'd be lost...

The bearing set's I mentioned above, may not work correctly and they came up as being for the Gen VI 7.4L and did not state there was several different placements and sizes. IDK

There's also a Clevite-V series which use lead and 2 layers... and a groove, sold individually. No idea if you can mix them... I would think not...

I did not see the GM Performance bearings offered for that engine, so I'll have to research where your knowledge goes...

Will bump this thread when I can answer the questions you and Bextreme04 have asked.

You guys Rock!

 

[Bextreme04]

The rods have studs. You would need to take everything to a machine shop if you mess with them. The main bolts are beefy and not one time use. Gen VI and Gen VII are all four bolt mains. If they aren't broken or visibly deformed, reuse them.

Again, I would FIRST mechanically check the oil pressure with a priming tool and known good mechanical gauge. The oil pressure gauge in the cluster is fed from the three-wire sensor near the distributor on the back of the block. It has a one wire sensor and two wires for a fuel pump switch all in one sender. If you get 0 oil pressure on the mechanical gauge with a priming tool running, then you need to get into pulling the oil pan and inspecting bearings.

 

[RanchWelder]

The rods have studs. You would need to take everything to a machine shop if you mess with them. The main bolts are beefy and not one time use. Gen VI and Gen VII are all four bolt mains. If they aren't broken or visibly deformed, reuse them.

Again, I would FIRST mechanically check the oil pressure with a priming tool and known good mechanical gauge. The oil pressure gauge in the cluster is fed from the three-wire sensor near the distributor on the back of the block. It has a one wire sensor and two wires for a fuel pump switch all in one sender. If you get 0 oil pressure on the mechanical gauge with a priming tool running, then you need to get into pulling the oil pan and inspecting bearings.

Great.

Do not mess with rod studs, reuse mains... Check
3" rubber hose over studs... now that makes sense... check

Is there a place on the block or cylinder heads, where I can verify oil pressure without ripping off the manifold and accessing the rear sensor on either config?
If I need adaptors or metric threaded brass fittings, for the area you recommend, I'll need to order them and have them delivered so the testing does not get held up with small parts...

What are the odds of removing either oil pan on the Burban... Concerned if it turns out to be the 8.1 it may be impossible to drop the pan...
Is the Gen VI any better if it's the 1999?
Will lifting the engine off the mounts be required and would you recommend removing the flex plate to converter bolts before pushing and pulling the crankshaft to determine existing movement?

Awesome...

 

[Buck69]

Is there an earlier thread related to this one? Not sure if I missed something, but what symptoms led to a bad oil pump diagnoses? Checking pressure with a mechanical gauge would be step one for me. If the engine has a knock, opening the filter and looking for debris would be the direction I went.
As Ricko1966 says, pull it if there is any trash in the lube system.
You don't want to be trying to clean up any scarred journals while in place, if you are looking for any kind of longevity.
Sorry, not familiar with this particular engine, but I do build diesels for a living.
Kicked out a DT530 Navistar last week and have an L10 Cummins and 60 series Detroit on the floor this week.

 

[RanchWelder]

I'm not certain Buck69...

All I know is the gentleman gave me the impression 2 years ago, it had an 8.1L... and a bad pump diagnosis... asked me if I could fix it. Because the 2 repair shops here in town get kinda weird if I help someone out, it turns into: "He's taking a customer from us", so I politely turned down the job.
Small town stuff... can get very sketchy some times.

Then Monday when I asked to buy the truck from him, he said he thought it was a 1999 (which has the 7.4L, not the 8.1L) and told and told me it was mine... about fell out my chair.

So I'm prepping for my first Big Block crankshaft/oil pump repair and a bit in the dark until he calls me to come get it. It's probably frozen in 6" of ice around the tires, with who knows what kind of air pressure in them... and a dead battery. He has 2 remarkable yellow show tractors and a very large shop for his Pivot serving business, so I suspect the truck is the last thing on his mind with family and all his companies he manages. It was only used for plowing a few winters. He bought it from my previous landlord 5 years ago, so it's kind of in the friends and family program with a good pedigree of honest maintenance. Has a plow on it... not likely he's going to be able to use it anywhere else...

He's a very competent guy, with lots of irons in the fire... . Soon as I know what's going on... the actual issue will be more obvious...

Found this post on another forum LINK:

Questions on using a Gen VI 454
By: 442Olds
"One last thing, the rear main cap on the gen 5/6 uses a small oring under the cap where the oil passage from the oil pump goes from the cap into the block. DO NOT DISCARD this oring from your rear main seal kit, it has to be in there to keep the oil from leaking right out. It yeilds very low oil pressure if its not in there. I found this out from the first book listed below and was lucky enough to find it before I started the engine for the first time."

Here's the book 442Ols recommends buying... and is where this engine saving tip came from:

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Look at the price in this Amazon sale page^^^^^^^^^^^^^^^^^^^
This is from today, not the wayback machine or a photoshop, this book is $9,999.97 as I write this at Amazon Books.

This guy want half price:

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I'm kinda wondering if there's anybody who has ever had this tiny o-ring fail and lose pressure, like this guy mentions knowing will happen if you leave it out on a rear mail seal replacement...

Re Your advice:
Cut the filter: ... (Check...) ...is well received. If the plastic connector for the distributor drive rod or the small o-ring is in there, the mystery may be solved.
Had enough of finding metal shavings in my pan for a good long while... we'll see after it gets here for surgery.

Tried to find that book on the web, hoping it was a typo...

 

[Buck69]

Interesting. Hopefully this turns out to be a best case scenario and you don't have to tear into it too deep.
I get the small town thing as we live in one ourselves.

 

[Bextreme04]

That book is widely regarded as the one to have, but when I went to do mine it is almost impossible to find. I ended up finding specs for the engine at a few different places to use for the rebuild. There really isn’t anything too special about them.

I’m not sure how easy it would be to access in the truck, but you can pull the oil galley plug above the oil filter or right behind the power steering pump. Here’s some pics of the locations on my 97 Gen VI as it’s out of the vehicle and easy to see. It will be a bit different in the suburban because of the oil filter adapter and other differences on mine, since it is set up to go in a squarebody.

All the bolts and holes on a Gen VI are SAE. Gen VII is a weird conglomeration of metric and SAE.

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[RanchWelder]

Wow... that's cool. Looks 1/4" NPT in either location... I may have the fittings to make it work.
Not having a ride to run down to the parts store is going to make this interesting for certain.

I can use the fittings from my new transmission test system, if it's dead anyways, so that's what I'll do.
Spent all night digging through the parts and establishing a worst case scenario budget and compiled the must haves to get it tuned up and rebuilt.

Your engine is looking great. I see the pins all pulled for the Black Box to 0411 swap?

(The trade show dolly is cool too!)

The thought of having to try to use the oil switch hole back there was giving me a head ache.
You saved the brain pain.

What is the three wire sensor used for?

 

[Bextreme04]

Wow... that's cool. Looks 1/4" NPT in either location... I may have the fittings to make it work.
Not having a ride to run down to the parts store is going to make this interesting for certain.

I can use the fittings from my new transmission test system, if it's dead anyways, so that's what I'll do.
Spent all night digging through the parts and establishing a worst case scenario budget and compiled the must haves to get it tuned up and rebuilt.

Your engine is looking great. I see the pins all pulled for the Black Box to 0411 swap?

(The trade show dolly is cool too!)

The thought of having to try to use the oil switch hole back there was giving me a head ache.
You saved the brain pain.

What is the three wire sensor used for?

Yes, I have a 24x tone wheel in front with the distributor just providing the 1x cam signal and it is running an 0411 with coil packs. The stock oil pressure sender in back is actually a 1-wire sender and an oil pressure switch that provides a bypass power feed to the fuel pump all in one 3-pin plug. I decided to leave that in place and use it to run the oil pressure gauge in the stock dash gauge. The second sensor plumbed in over the oil filter is a three wire 5v reference oil sender that will feed oil pressure straight to the 0411 so that I can data log it and also have a backup oil pressure source. Apparently, you can get the sender with the correct 1/4"NPT thread from a 4.3l v-6, but the one I have is an LS sensor with an adapter from ICT Billet.

 

[RanchWelder]

Here's what I got coming...

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Wouldn't be a MT truck without the rodent nest...
The mystery is solved... Body looks great leather seats are nice.
Had a plow, had to be removed, so the parts are in the trunk... everything is mint-ish.. except that filthy engine bay...
Tires frozen in and rotten... but I have a set of 16"'ers to make it work.

My first Big Block since 1994... that one was stolen... 29 years a long time to wait for another BBC.
Your engine would look sweet in there...