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Discussion Starter · #1 ·
not exactly MKIII specific but I know rod knock is a typical thing for us MKIII owners (knocks on wood).

Now, I've heard and read here a few times about people dropping their front cross member and pulling the oil pan...then changine the bearings from there. How does that work? Can you pull the drive shaft from underneath the car like that? If the crank bearings were out wouldn't pulled the drive shaft and having it checked be essential? How can the bearings even be replaced without pulling the shaft?

Please clear up this confusion for me...
 

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No offense man, but I suggest you take a long read through the TSRM and come back and ask questions that make sense.
 

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I think you mean crankshaft

usually, going from the bottom is ghetto (from my experience). If you are gonna do it, do it right, and pull the engine. Pulling a crank from the bottom would be a pain! Putting it back would be even harder! I don't see why you couldn't though.
 

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You would need to yank the driveshaft so you can drop the tranny, but other than that it's not really related to changing crank bearings at all.

While you could drop the cross memeber to do it, I have no idea why you would want to. It would be much faster to yank the engine/tranny up and out. Keeping things clean enough while working under the car is going to be next to impossible too.
 

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:agreed:

the driveshaft comes out the back of the transmission - I think you are talking about the crankshaft. Pull the motor.
 

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Discussion Starter · #8 ·
keep in mind that I did say it isn't exactly supra specific...I'm looking at a rod-knock victim. If I go that route then the engine will be pulled...it's just not the only car I'm looking at.

If an engine has suffered a spun bearing or has begun to thrash a bearing, would damage to the crankshaft be evident? Like, would there be obvious pitting and such? If there isn't noticable damage should I be concerned?
 

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The journals should look perfectly ground, with a surface finish around 4 micro inches RMS. I would advise you have someone who knows what they are looking at examine it with you. If everything is normal, the journals will usually wear a tenth or two over 100 kmiles, causing the need to go to the next larger size bearing.

In any case, if you spun a bearing, the crank is trashed, period. Replacing the bearing without fixing the problem will just cause you to go right back in again.
 

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Discussion Starter · #12 ·
so basically what the eye can't see can still hurt it? Cool...thanks man. I'll take it to pro to have it checked then.
 
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