main bearing fried or thrust bearing?

[spyder1219]

The photo is the middle main bearing, not sure if that is also referred to as the thrust bearing? Well looks like i need a replacement either way. This is the only bearing that looks like this too. So what does this imply?

Does the crank need machining and/or polish (i have read to NOT machine the oem cranks?)

Can i get away with just new ACL trimetals and solve this problem?

Do i need to buy a new crankshaft?

On a side note, what is the best way to remove the center bearings? Those bastards are on there super tight with that lip. It took a flat head and hammer to pop them off. Any other easier methods for the center bearing?

Just click the pic to get to a bigger shot

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[DSMDEMON93]

Yes the middle bearing is referred as the Thrust Bearing. It is interesting that is the only bearing that shows wear. It's possible that the rod bearings were replaced at an earlier time. The crank should be alright. If you are not sure, rub the edge of a penny on the journal and see if copper rubs off. If it does, it will need machining. Also, look for discoloration around the bearings, feel the journal for graininess. Look for damage if the crank rubbed into the block. If all of the above check out ok, slap in some new bearings and keep going. The easiest way to remove those bad boys is to use an older bearing as a little dowel pin, and use a hammer on the outside to pound the old bearing out, so the old bearing does not damage any surfaces.

 

[bryanwheat]

With that kind of damage you need to remove the crank and have it machined or replace it. I would be willing to bet money that the crank is out of spec.

 

[evileagleawd]

Mic the crank if you dont have a mic run it down to your local machine shop they will take a look at it but bare minimum it probably need to be polished! Also did you inspect all the main and rod bearings? You might have a oil supply issue!

 

[JacksonAuto]

Is this the only bearing that shows damage? I cannot tell from the photo but did the bearing spin? If so you'll be needing a new block.

At the very least you're going to want to tear the engine down to clean and inspect everything. You will want to clean and magnaflux the crank to make sure it's not cracked. A lot of times when a bearing is damaged that badly a tremendous amount of heat builds up and destroys the crank. If it's not cracked, the crank can be saved. It is possible to machine these cranks with no ill effects. Clean all of the parts and be sure to flush out the oil galleys in the head and block. Take it to a machine shop to have this done. They'll be able to inspect everything and they know what to look for so then they'll be able to suggest what needs to be replaced and what likely caused the failure.

 

[BogusSVO]

Is this the only bearing that shows damage? I cannot tell from the photo but did the bearing spin? If so you'll be needing a new block.

At the very least you're going to want to tear the engine down to clean and inspect everything. You will want to clean and magnaflux the crank to make sure it's not cracked. A lot of times when a bearing is damaged that badly a tremendous amount of heat builds up and destroys the crank. If it's not cracked, the crank can be saved. It is possible to machine these cranks with no ill effects. Clean all of the parts and be sure to flush out the oil galleys in the head and block. Take it to a machine shop to have this done. They'll be able to inspect everything and they know what to look for so then they'll be able to suggest what needs to be replaced and what likely caused the failure.

^^^^^^ ALL Of this!!

The engine needs to come out and be cleaned!

What I will add is that the oil cooler needs to be replaced, so no metal will be in the new engine on start up.

Also, have the big end of the con rods checked, to make sure they are still in spec.

With the thrust bearing, looking like that, loss of oil, the mains get oil first then the rods.

Look around where you removed that main/thrust bearing, if the area around the main bore is black. You will need to replace the block!

But if you are feeling a bit lazy, and do not want rebuild your own engine.

Pick up the Phone and call JAM and order you one of their short blocks!!
(Shamless supporting vendor plug!!)

 

[spyder1219]

my apologies if youre colorblind!!

i think the block is toast already, heres why. the yellow circle is missing something important. The red circles are stripped completely and the green circle that mates to the transmission, inside the transmission is the broken bolt.

I have a set of calipers, anyone know off hand the size i should be looking for on my crank? all the rod bearings are looking good and the other main bearing are pretty decent for being 20 years old. At least i think so. i didnt ask the previous owner if he rebuilt or not. I bought it like this.

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[BogusSVO]

Yep you have a nice door stop with that block.

Time to hunt up another block.

 

[92AWDHX40]

Yes look for another block i see them in classifieds and ebay for cheap.

 

[JacksonAuto]

I have a set of calipers, anyone know off hand the size i should be looking for on my crank? ]

You'll need an outside micrometer. A set of calipers will measure to .001". You need to measure to .0001" ACCURATELY.


We've got a bunch of 6 bolt core blocks if you want us to put something together for you.

Thanks Bogus for the shameless plug!