babyfood1217

I have been scouring a number of the sections within YT for a DIY/writeup for a rod bearing service job, but haven't come across much. In fact, I only found one post with only two pictures, so I'm hoping someone can either post a link or at least explain a little in the spots where I have missed...

My truck:

1988 4runner - 22re with a 5speed

Why I need to do this:

Starved the engine of oil. The shop I had put in my new OER motor this spring fouled up big when they failed to remove the paint from the block where the timing cover mates. They also failed to scrape the old gasket from the timing cover when they put it back on. Just tossed a new gasket on and and tightened it up. I caught a little from this area months ago, but tightened the bolts up and it went away. Well, many miles later and after a cross-country trip to Seattle from Wisconsin (I moved out here for work and love and life) the leak showed up again. Smaller at first, but getting exponentially worse. So bad in fact, that on Friday, Oct. 29th, I sprung such a bad leak from behind the cover, that by the time I could safely pull the vehicle off the road and out of traffic, it started knocking and died. Had it towed to a shop where they fixed the timing cover gasket leak (hence finding the gasket remnants and paint left on by the previous shop.) After running the truck and letting it warm up, they too heard the knock. The owner said it was most likely a rod bearing. He said I could drive it gingerly for a little while, but should address it ASAP.

So, to fix it I have narrowed it down to either taking it to a shop or doing it myself.

Shop:
-Pay them a ton of money to do it. Job done.

Me:
-Systematically pull one plug wire at a time and run the engine. Hopefully the knock will get quieter at one of the 4 cylinders when I do this, more closely indicating a rod bearing. If the knock does not disappear with this method, I've likely got other fish to fry.
-Get a plast-gage set (green I think) After finnagling the oil pan off and out (I have a couple threads on that bookmarked right now too), I will remove the rod caps and visually inspect for cracks//damage on the bearing and for gouges on the crank. Crank damages mean it will need to come out for an overhaul (grinding and oversized bearings.)
-No crank damage assumed, I will wipe clean the bearing surfaces and install a plastigage, reinstall the rod cap and torque appropriately. Subsequent removal of the cap and measuring of the plastigage will reveal what bearing would be appropriate (OE spec, or undersize. Uneven thickness in plastigage reading may reveal the need for a crank regrind.)
-No uneven thickness assumed, I then determine which bearing set to get. I haven't looked at the FSM yet, I know there are tabs on the bearings to aid in alignment/placement. What I don't grasp is how the bearing will come out. Do I gently pry at it? Will I need to use a drift and carefully pound it out? I'm sure I could manage to get the bearing out of the cap, since it won't be stuck in the engine still, but getting the bearing half out of the rod worries me. I feel like I'll have to drop the caps, and systematically rotate the engine some to allow for clearance to pull the upper half of the bearing away from the rod. Correct?

Any sort of writeup on this would be greatly appreciated..

-Chris

MudHippy

Use a piece of hard plastic to poke the upper bearings out. Get them started out and then use a metal pick, or similar, to slide them the rest of the out. Careful not to scratch the journals with the tool. That should work for the rod bearings. A roll out pin would be useful for the main bearings. Which you might as well do too.

New bearings can be lubricated and slid into place by hand.

babyfood1217

So I just had a chance to run through the motor and try the systematic "pull the spark plug wire and see if the knock goes away" trick. Well, after running front to back (1-2-3-4) the sound/knock was there on all but number three cylinder. Yup, with the number three wire pulled, the knock disappeared. The engine didn't sound great as I cautiously gave it some throttle, but there was no knock. It was obvious and easy to hear when trying this trick with the other cylinders, however. This leads me to believe (not confirming anything!) that perhaps I spun my number 3 rod bearing.

So...

When I get a another clean/dry weekend here in Seattle (yeah, right) or perhaps can secure a garage or dry space to work in, I am hoping to tackle not only the oil pan drop on an IFS truck, but also measure and hopefully replace the rod bearings.

Things I am sure that I need...
-Assortment of wrenches and sockets (and extensions)
-Torque wrench
-Plastigage (green, correct?) for determining which bearing kit to get*
-RTV sealant for putting the pan back on
-Jack stands
-floor jack
-beer
-patience

Concerns...
-I've never done the oil-pan drop before. Read some threads on here describing easy and well as horrible experiences. Biggest concern I have about this is making sure I get an good RTV gasket built up so I can not have more oil leaks
-I've never used plastigage before. Seems pretty straight forward: lay down strip, torque everything back together, undo, measure strip. I believe I would then divide the number by two to determine the correct bearing, right? The motor has less than 15k on it, so I'm hoping I'm close to standard bearing size.
-I'm obviously worried that once I get the pan off, and take the rod caps off and look at the rod-bearing-journals on the crank, I'll find gouging. That would mean not only did I do this work for nothing (the engine has to come out for a crank machining) but I would also have to shell out for a crank machining.
-I'm just freaked out about all of this either way. This is technically my daily driver (currently, sitting outside my apartment, not being used.) so I don't want to risk to much down time by starting to tackle something I can't finish. I am WAY TO SCARED to drive it right now, albeit gingerly, with that rod knock happening. Just too scared.

Does anyone have any tips, suggestions or warnings about this procedure that they feel would be helpful? I'm obviously scouring as many threads as I can hoping to gleen as much info as possible, but I'm bound to miss something...

Help!

-chris

TOYOTA 1

the bearing sizes will be marked on the underside of the old bearings.

the best way to remove the pan is to drop the front diff. it can be done other ways, but with that diff out of the way its much easier to get the pan off, do the bearing job etc.

ive saved a few motors by "rolling in new bearings". do one rod at a time. role the motor over until the rod that your working on(i would start with #1) is facing all the way down. pull the rod cap off. then slide some rubber hose over the studs. with your 2 thumbs softly push the rod/piston up into the cylinder. then role the motor until the crank journal is to the side of the block and out of the way. reach in there and pull the rod/piston down as far as it would be if it was connected to the crank( makes the bearing more accessible). use your thumb and push up on the edge of the bearing. the bearing will slide/role right out. clean the rod thoroughly, then install the new bearing. i line up the tang side first, then push the bearing the rest of the way in. do the same to the bearing that's in the cap. after the new bearings are installed/ lubed, push the piston/rod back up into the cylinder. role the crank back down so that the journal is facing all the way down. pull the rod on to the crank, then remove the rubber stud covers and install/ torque the cap. then do #2 #3 etc..

i probably could have worded that better but im kinda busy gaming at the moment

hope that helps a little, Mike.

BigBluePile

iTrader: (3)

Wow, that's quite the undertaking for an apartment dweller. But sound advice from the above posters. Yeah, unfortunaley, without a drop bracket lift on your truck you're gonna have to pull the diff. However, you'll be thankful that you did because you'll have all that room to work. Good luck!!

Cyberman

To help get the oil pan off, take a 2x4 or other piece of wood and whack the edge a little bit to loosen it up. Prying on it isn't quite as effective. Use black RTV and follow the instructions to make your pan gasket. Make sure the surfaces are clean and don't use too much.

As for the plastigauge, You want to check the tolerance against the FSM to determine whether they are ithin spec, and also how much more over stock you would need to get.

Also, I don't want to scare you, but when I had my spun rod bearing, it did score up the crank enough to need machined, in which case the engine needed pulled. The machining of the crank cost me around $150 but they also let me know exactly what size bearings to get. I've heard of others just putting new bearings in, but it usually results as a bandaid.

If you check out my rebuild thread, there are a couple of audio clips that give you an idea of how bad my knock was.

babyfood1217

Oh you did, don't worry...

Actually, I'm very nervous about all of this, simply because I AM AN APARTMENT DWELLER! No garage, no shop, no engine hoist, no other vehicle aside from a bicycle, and to top it all off, I'm new to the area and the area is Seattle, where it is about to start its' 4 month rainy season.

I don't know how to do it yet, but I'll try to take a video/audio clip with the engine running. Maybe one with all four getting spark and one with a spark-starved #3 cylinder (which is when the knock disappears. I pretty much just flushed my dollars down the drain to get my massive oil leak fixed, so I'm left without too much to ride on here. Ha, on top of that I'm pretty sure I'm going to need a root canal, also without insurance yet! Hooray!

xxxtreme22r

I would be willing to bet as razed said that if the bearing toasted there has got to be bearing material anywhere in the crank passages and most likely the block as well. if It's #3 then #4 bearing passage has to have bearing material in it as the #4 bearing is the last to get oil in these motors. I know this because while talking to Ted @ ENGNBLDR during my rebuild process he had mentioned it.

I really think changing bearings in instances like this is just a big waste of time and money. Now if you just bought a truck and notice a little bit of bearing knock then maybe it "might" work, but if you ran the thing out of oil and now there is a knock that wasn't there to begin with and the motor was run for any length of time with the oil light on then a rebuild is the only thing that is gonna work and this includes sending the block, crank and anything else that has oil passages into a machine shop to get hot tanked and whatnot.

xxxtreme22r

if #3 goes out the oil from #3 goes into #4 along with any material from #3 in which #4 would not be too far from going out if #3 failed had it continued to run. I have actually seen this first hand don't ask. lol.

I'm not surprised #4 is fine myself though as in theory because it's last in line actually has a lower oil pressure but it's also the last to get oil.

Hard to think about it in line though because it's really not. each rod is supplied by the same passage in the crank. But when you remove that oil flow from in the beginning of the chain then it might as well be a direct line. once the oil is done moving past the one hole it essentially sucks what material might be sitting there in the previous journal into the next one.

what gets real tricky to explain is if the bearing itself spins and blocks off it's supply hole. I don't think that's his problem though as if this were to happen there is a good chance the crank would seize. Like which was my case on my first rebuild.

TOYOTA 1

If you catch it quick enough it does work. I have done itO to a few motors. ie, Spun a rod bearing on my 91 in 05, drove it for 2 weeks with a slight knock. Roled in new bearings ran it hard for another 2yrs no noise. Blew a hg decided to rebuild it, machine shop said the crank was cherry. That was back in 07, been running it ever since with no problems / noise. Granted, the longer its ran that way the smaller the window of opportunity gets.

babyfood1217

I'm only run the engine with the knock for maybe an hour. Less than a minute or so when it first happened, I'm sure a few minutes in the shop when the techs were diagnosing, and then the 25 miles trip home from the shop, at less than 3k the whole way.

xxxtreme22r

Yeah I can see that because it's a small knock due to wear, this guy ran his out of oil !!!