Real Time- Rod Bearing Carnage

[CruisinGA]

Reference these threads for background.-
https://forum.ih8mud.com/80-series-tech/210792-low-no-oil-pressure.html
https://forum.ih8mud.com/80-series-tech/211312-below-spec-oil-pressure.html

Semester finally ended and I am getting to tear into this. See pic of all the rod bearings. I have no experience with bottom-end work, but these sure don't look good to me. Crank journals seem fine, smooth to the touch but two have barely detectable "ridges and valleys" that don't catch your fingernail but you can feel when you run your fingertip back and forth.

So, is this the kind of wear that could lead to the low oil pressures I was experiencing?

I'm going to pull at least one main to check, if it checks out would ya'll replace all the mains anyway or leave them be?

 

[CruisinGA]

Pulled the 2,3,4,5,7 main caps & bearings and I attached the picture.

A picture won't show it, but a few of the main and rod journals on the crank have very slight ridges and valleys in them, not enough to catch on a fingernail but enough to feel with a fingertip. It's been suggested that I go ahead and pull the crank and have it checked out by a machinist.

Any thoughts? Pulling the crank is a significant addition of work and expense, since I would have to buy a transmission jack.

 

[NLXTACY]

Do you know the tolerances of the rod bearings? In other words have you tried the thread gauge test to see how far off from spec you are? Thread gauge you can get from any auto parts store. Its usually located in the, "I'm-a-stupid-auto-parts-idiot-and-I-have-to-freaking-idea-what-this-is-aisle"

I would venture to guess by looking at those rod bearings that they are out of spec. Find out where they are and get new rod bearings. Normally I would say have the crank ground to true it out but thats a huge undertaking to drop the crank too.

I've never done it in a landcruiser but I've done a few hundred otherwise. Previous life.

 

[NLXTACY]

Honestly, you are already there. I would take the time now, being as you have done 90% of it, and remove the crank and have it ground. Then you can test the spec and see what oversize main/rod bearings you need.

 

[Cruiserdrew]

Ouch. You are fawked.

This motor was run with an oil starvation situation. I'll bet the mains will have the same wear.

While you could replace the mains and the rod bearings, my guess is that this motor is done. Time to rebuild or replace.

 

[NLXTACY]

I wouldn't really say that. He has the entire bottom out basically out. If he has the crank tested and ground, bottom end should be ok. As long as the pistons are out, take off the head. How do the sleeves look? Are they heavily grooved? If not then you can probably just run a ball hone down each cylinder and then get the head cleaned up and surfaced. You can do the rebuild yourself. Its not that hard. You "could" do an in chassis rebuild. This is assuming you dont have serious oil coking going on. If thats the case then you need a total R&R. I've seen much much worse.

 

[CruisinGA]

I described the situation showed a couple rod bearings and described the crank to a guy at work who is a research tribologist (friction scientist) who also has a lot of experience building engines.
He is certain that the amount a wear on the crank I am seeing is normal for an engine with my mileage, and that the rod bearing wear is the culprit for my low oil pressure when hot. His opinion is that I can just replace the rod and main bearings with new stock units and run it.

There is no scoring on the cylinder walls that I can see, and the engine still ran fine after the incident, just with below spec oil pressure when the engine got hot. Haven't seen any oil coking in the parts of the engine I have exposed.

I'm leaning heavily towards just replacing the bearings and buttoning it back up.

 

[NLXTACY]

Seriously you would probably be fine. I would say for me, if I had that much of the bottom end out, I would definitely have the crank ground. And please please please use thread gauge and torque to find out what your tolerance is. You don't want it to be too far out of spec and spin a bearing. But if you decide to run with just new rod/main bearings I would say you would be ok....JUST spec it!!! Thread gauge is your friend.

 

[CruisinGA]

I feel you on the "you're this far" mindset, but getting the crank out would be twice as much work as I've done thus far and require tools I do not have nor have the money to buy. (trans jack, 300 ft lb torque wrench etc).

If it really wasn't that much more work I probably would go ahead and pull the crank.

 

[NLXTACY]

You can rent them both. AutoZone and PepBoys have rental programs. And its cheap....as long as your aren't late

 

[Tools R Us]

From your pix I would guess that your crank is OK. Is there any bearing metal transfered onto the crank? Can you shoot some closer shots of the rod bearings, preferably some at an angle to the bearing face?

The bearings don't look that bad, looks like normal wear/startup scuffing, but it's hard to tell in those pix.

 

[Tools R Us]

....JUST spec it!!! Thread gauge is your friend.

X2, Plastigage is way cheap and will show your oil clearance. Stock speck is .0017-.0024", with a max of .0039". Get green Plastigage and check it, most good parts and/or hot rod stores carry it.

How To use plastigage to measure clearances | eHow.com

Summit SUM-PG1 - Summit Plastigage - summitracing.com

 

[Cruiser Jimmy]

Wow, those bearings have seen better days. I would have to error on the side of caution and say get that block out of the rig and polish up the crack to get any debris off the crack.

Rolling the top crank bearings out is going to be a chore in itself, but then getting some crockis cloth up in the journals while the crank is in the block then cleaning is even more of a pain.

 

[fj80toyman]

I understand why you don't want to pull the crank. I would be flipping the same coin. By the way, no auto parts store along the lines of auto zone has a torque wrench that will pop 304 ft-lbs - at least not in my neighborhood. Trans jack? Gotta go to the specialized tool rental place for that one too. Harbor Freight is your friend on both counts.

If you do just the rod and main bearings, plasti-gage at the minimum. Before that though, there's a trick for smoothing out the rough spots by taking some emery cloth just the width of the journal, wrap it around each of the journals. Then take a leather shoe lace, wrap it around the cloth once or twice and do a little back and forth for a minute or two on each journal. This will get the surface roughness out.

A double for that one!

After that do the plasti-gage and if it's out of spec, you're not out much coin - if it's in, you're likely good to go. Almost hate to give that advice but if you're going to drive it yourself you know what you've done. If you do sell it, be sure to let the next guy know what he's got.

Good luck.

 

[NLXTACY]

If its out of spec you can get oversized bearings. Should be able to get .001-.002 over if you are really intent on not removing.

X2 on emery cloth.

 

[CruisinGA]

The plot thickens...

While waiting on bearings from Japan, I decide to pull the throttle body and valvecover to do some much needed cleaning and resealing.

I found a little surpise under the valvecover- what I believe is a chunk of the timing chain tensioner slipper. See picture below.

Is my ID of this piece correct, and if it is, is it possible that the overextended timing chain tensioner could let enough oil pass to end up with a situation like I had?

To R&R the timing chain tensioner, is it necessary to pull the head?

If I have to pull this head then I am going to either pull the engine and rebuild it or do "something else" (diesel/v8).

 

[OGBeno]

Yup. That's the slipper Bailey....

You need to take the timing chain cover off to get to the slipper and the like.

You will need to take out all of the crap in front of it to get to the cover.

At this point man, you might as well start thinking rebuild.

Hate to say it.

Good luck and my offer still stands.

-onur

 

[Beowulf]

I found a little surpise under the valvecover- what I believe is a chunk of the timing chain tensioner slipper.

Bailey,
Your pictures appear to be of your '93 engine and not the '97 engine. We have had several reports on the early 1FZ-FE (93-94) of problems with that slipper breaking apart as yours has done.

You don't have to remove the head to remove the timing chain cover. Still a good bit of work though and you have done most of the work by removing the 2 oil pans. Read C-Dan's oil leak thread to get an idea on the job and the things you should do "while you are in there..." In fact, you may want to replace the 10-cent plug that popped out on his.

You also have a substantial oil leak at the front of the engine. Maybe the dizzy O-ring but probably the front main.

-B-

 

[CruisinGA]

Onur- thanks for the offer. If it comes down to rebuilding or R&R on the head, I'm just yanking the engine.

B- It is the '93. I talked to Dan today about his oil leak repair. I am going to attempt to replace the tensioner slipper without removing the head, like Dan did. All that oil is from the valvecover and dizzy O-ring. The front main and upper oil pan also leaked. All of which is getting replaced.

Basically, my long term plans for the truck don't include this engine, and since the crank looks fine, and early trucks are statistically less likely to blow a headgasket, I'm just trying to get the truck running as quickly/inexpensively as possible without taking shortcuts. It also looks like I never actually ran the engine out of oil, but rather the overextended tensioner was letting a too much oil by. If I had to pull the head/crank or engine I would just yank it all and start on my other plans.

 

[OGBeno]

start on my other plans.

He, he, he...and what might these be?