Hello Guys / Gals,

What does a "spun" bearing sound like and how could I diagnose?

Is it fixable or does it damage the block and or crank?

I just picked up a '95 4Runner with the horrible 3.slow. The poor seller took a beating on it because he had just bought it 1-24-11 from a shady dealer and soon after changing the oil started hearing a loud noise. Whatever the Toyota dealership told him it scared him into selling it. I have never heard a spinning crank bearing but I don't know what else it could be (maybe torque converter?)

Here's my description:
Start the truck and notice an immediate chichcichichichichi quote loud inside and hard to say where it is coming from
Pop the hood and you can hear it but can't place the location.
Climb under and here it very loudly at the back of the oil pan or bell housing location. It is definitely not anything like a knock.

I'm going to buy a mechanics stethoscope and see if I can place it better.

Anybody successfully changed main bearings with the engine in the truck? Anybody heard of such noises coming from a torque converter?

Thanks in advance.

 

rod bearings are normally more of a thud thud thud follows engine rpm's gets louder when more throttle is givin, wrist pins or piston slap higher pitched clack clack clack typically happens at higher rpm and when letting off the gas. lifter noise is more of a tick tick tick.

 

rod bearings make noise when unloaded typically, meaning at idle and on decel as well as higher RPM. As well as on startup when the oil pressure is low.

It's almost the same symptoms as a 22r timing chain. But since his is the 3.0 then it's not his case.

Just slapping bearings in a motor already making noise is just a bandaide fix and could very well wear another bearing out very quickly.

This I know because I drove a full year and maybe 6,000 miles on a truck that evenually spun a rod bearing.

 

Thanks guys. It does NOT seem to get louder with rpm and it is there from startup till turning off. It also makes a grinding to a halt sound when the engine turns off. It is more of a light gauge metal scrape sound (high volume) than a thud or knock.

I'll get a video of it so we can play name that noise.

If slapping bearings in is a bandaid how is a rebuild different? If a main is spun do I have to get a new crankshaft? Is it possible to spin a main bearing or only rod bearings?

 

possibly to spin both, on a rebuild you are pulling the crank and having it checked and turned for oversize bearings if it's bad or just replacing the crank like I did.

 

Thanks to Autozone I picked up a cheap stethescope. It was pouring down rain and my new Runner was in a metal building so I almost didn't even start it up but I figured why not. I crawled unerneath it and could definitely hear the noise over the rain and engine. I poked around the engine and it sounded beautiful. Stuck it on the bellhousing and could hear the scrape / chuching sound. Off to the side of the bell housing it gets quieter centered (left to right) near the back it is the loudest. I guess I'll be pulling the tranny instead of the engine.

 

had the same thing happen to my 93 a few years back... I lost my drive shaft at 80 mph on the highway (long story) and as a result it bent the output shaft on the transfer... I drove it that way for about 17k miles before the torque converter finally pushed its way thru the bellhousing... Id get that tranny outta there asap, and see whats goin on....

 

sounds like it could be a broken flex plate, i used to have a dodge dart with a biult 318 that would break them all the time.

 

I finally got some time to look at it again while my wife and kids were napping this afternoon.
Turning the engine by hand with a breaker bar yielded some spots where it would catch pretty hard and i could hear scrapping sound. It sounded like it was coming from the bell housing but hard to place. I removed the brackets and plate covering the torque converter access and removed the bolts between the flywheel and TC. I again turned the crank by hand and it seemed like the catch was gone but now the flywheel is scrapping on the torque converter (TC not turning). I used a screw driver and an angled pry bar but cannot move the TC back at all. Cranking the engine just makes a terrible noise since there is no space between the TC and the flywheel. Shouldn't there be a way to back the torque converter away a few mm?

Should I take the transfer case off first or just leave it on the transmission?

 

I don't think you can remove the transfer case if it's an auto.

 

ok. Good to know. Seems like it would be a bear to get lined up on the way back in though.

I have changed a few front wheel drive trannys but never a 4wd. I might start pulling it tonight. I'd just like to be able to hear the engine run clean without the noise that way I know I'm pulling the right thing. It wouldn't be the first time I've swapped the wrong part. Maybe I'll just have to trust my $10 stethascope.

 

So, now that I have been laid off from my day job (factory closure) I can do my 2 other jobs during the day and some mechanics at night. Finally got the transmission out last night. I can't feel any catches or grinding when I turn the torque converter slowly. I pulled it out and can't see any grinding / wear spots or metal shavings. The flexplate / flywheel looks fine with no signs of wear or cracks.

I really hate to just assume that the transmission is bad and by a new one, stick it in, only to find out that my stethescope was misleading me and it is a main bearing. So I want to start the engine with the tranny out. I used shorter bolts and bolted in my starter to the plate that sits between engine and tranny (is this the flexplate or is the flexplate same as flywheel?) Of course it didn't crank because it was looking for park. So I removed the selector location sensor from the tranny and plugged it in but still no juice. I guess I have to put the transmission half way into place and plug everything back in before its going to let me crank it.

Any suggestions? I saw a transmission on craigslist for $250. Is this a good price? He wasn't clear on the mileage.

Jon

 

Also, what transmission do I have. All these codes floating around have confused me. It is an automatic 4x4 for the 3.0 in 95. Where is it shown on the transmission so I can make sure that one I get (if needed) is the same?

 

A flywheel and a flexplate are basically the same thing except a flexplate is used for auto transmissions and flywheels are used in manual transmissions. Did you turn the motor over by hand with the tranny out? Did it feel any different? And I believe you have the A340F transmission.

 

http://img92.echo.cx/img92/5992/vehid5yg.jpg Check this out. It will tell you how to identify your tranny.

 

this one might be easier to read:

 

Thanks Guys.

It looks like I have an A 340H. My truck must have been the last one shippped over. It was made in November of '95.

Yes I turned the engine by hand after I disconnected the torque converter from the flex plate. It felt different than when I turned it over with everything connected.

 

Sounds like a great excuse for a 5spd swap!

 

define felt different, because the engine under normal conditions is gonna be harder to turn with the trans connected and you still have to turn the input shaft of the trans. Even on an auto. IMO actually more so on the auto since you have to deal with fluid in the torque converter.

 

Felt different - when I turned the complete system there was the normal compression plus 1 specific point in the rotation that it seemed to catch (like a bad spot in a bearing).

When I turned the engine without the torque converter I only felt compression. Although, one difference might have been temperature as it was completely cold when I turned it by hand after removing the torque converter bolts.

I'll lift my tranny enough to plug it back in electronically tonight and see if I can't get the engine to run. If the engine still makes the noise I'll probably just part it out. I drive a 3rd gen DD otherwise I might go for a 3.4 swap with 5 speed. ; )