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"fixing" crankwalk and now advice on my motor build

I know this topic has been discussed before, and that there are a million opinions out there, but I wanted to get some advice on my specific situation. I rebuilt my motor about 20,000 miles ago, and it has had clutch play, and classic crankwalk symptoms since the start. I had the block, rods, and head machined by a reputable machine shop in my area. The people at the shop ordered all the rod bearings, and main bearings according to how they machined it. I am now having a few other problem that are leading me to want to just yank the motor and deal with everything at once. If I do yank the motor, is there something I can do to fix the crankwalk without replacing major components? Can a thicker thrust bearing be purchased? Are there other things that can be done?

Any ideas/advice are appreciated.
 
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Barnes

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So.. did it crankwalk before AND after the rebuild? Is this a 7-bolt motor by any freak chance? Have you actually measured the crankshaft end play with a dial caliper?
 

SouthCaliVR4

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Ohh, my fav subject /ubbthreads/images/graemlins/devil.gif real responce will take some writing I'll post agin when I have a moment.
 

Quoting BarnesMobile:
So.. did it crankwalk before AND after the rebuild? Is this a 7-bolt motor by any freak chance? Have you actually measured the crankshaft end play with a dial caliper?



This is a 6 bolt motor. No, no crankwalk before the build.... just mad amounts of knock for about a year, and then the timing belt went. When I took the motor out I measured crank thrust before I disassembled the motor and it was in spec (.005 if my memory is right). Finished rebuild, and it runs fine, but the clutch depresses in left turns, and idle drops slightly when the clutch is depressed.

Edit: I have not measured crank thrust on the rebuilt motor. I can do that today or tomorrow. I was just wondering if there was a possibility that the wrong size thrust bearing was installed or something to that effect
 
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SouthCaliVR4

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" the clutch depresses in left turns" please clarify. And the six bolt dosen't have big time crank walk issues unless the clutch is huge, that is a seven bolt issue. they have wee thrust brgs.
 

Barnes

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You can still crankwalk a 6-bolt. It isn't nearly as common as the 7-bolts, but it does happen.
 

belize1334

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The drooping idle could be a symptom of a bad TOB. As for the left turn issue, I would think that if the clutch assembly were slipping to the outside of the turn then the clutch pedal would rise, not fall.
 

SouthCaliVR4

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Quoting BarnesMobile:
You can still crankwalk a 6-bolt. It isn't nearly as common as the 7-bolts, but it does happen.



Didn't mean to imply they "don't" just that it is not a common issue, I had two 6's crankwalk but it was a result of owners never doing oil changes, otherwise "I" have only seen it happen on heavy clutch cars, wich is not to say it wont happen otherwise.

My thing is the clutch switch, pushing the crank against the thrust brg wile cranking the engine over, This is of course my own humble opinion & I am not looking to start an off topic post war on the issue this time around. /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/devil.gif
 

Quoting SouthCaliVR4:
" the clutch depresses in left turns" please clarify. And the six bolt dosen't have big time crank walk issues unless the clutch is huge, that is a seven bolt issue. they have wee thrust brgs.



When I go around left hand turns the pedal looses pressure (I can push it about 3/4 of the way down without it doing anything, and it will stay this way until the first time I use the clutch after the left hand turn. Once I push the clutch in once, it "re-sets" and acts normal until another left turn is encountered.

It does have an ACT 2600 in it.... that will get changed if i yang the motor
 

Quoting belize1334:
The drooping idle could be a symptom of a bad TOB. As for the left turn issue, I would think that if the clutch assembly were slipping to the outside of the turn then the clutch pedal would rise, not fall.



When you crankwalk a motor its a classic sign if the clutch depresses around left turns. It happens because the crank slides toward the clutch assembly side, and the fork and TOB don't move causing the clutch to disengage without you pressing down the pedal at all.
 

SouthCaliVR4

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two person test. use a pry bar to push on the crank bolt,eng off of course. The have a bud push the clutch pedal in & watch the crank pulley, if it moves you have crankwalk. if you can hook a mag mounted dial indicator it will tell you exactly how much.
 

Thanks, but Im not really trying to figure out how to test for crankwalk. I pretty confident it crankwalked, but I have a dial indicator so ill check it out after work and get a reading. My question is more along the lines of what I would need to do in order to fix this while the motor is out of the car.

Do they sell thrust bearing that are oversized on those "flanges" to compensate if you have crankwalk? What can be done to fix it?
 

SouthCaliVR4

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it will depend on whether the crank took any damage or if just the brg is worn. generaly if caught early it's just the brg. If however the crank is worn as well I would guess it would have to be welded & machined, I'm not sure off the top of my head if the brgs come in any oversize for thrust.
 

Okay, sweet. If I do this I'm also planning on going with a lighter clutch because my plans for the car have changed quite a bit since I installed that clutch. Hopefully that would halp, or at least make it less prone to do it again.
 

Barnes

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Do you have your clutch switch disabled? I.e. You can start your car without pressing down the clutch pedal.
 

No, I have to start the car with the clutch in. I've heard about that and know how to do it (in theory), but just never did on my car.
 

Barnes

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I recommend doing this mod. It is super easy. Just unplug the clutch switch that is depressed when you press the clutch (there are two clutch switchs). Just gotta be careful from now on that your car isn't in gear. This should help prevent crankwalk on cars with heavy clutches. The most wear is at startup when you have no oil pressure. This combined with the load from a heavy clutch creates a situation that can create significant wear. Disabling this switch prevents this wear during startup.
 

Okay, Ill get that taken care of weather the motor comes out or not....

What kind of low pressure clutch do you guys suggest? Im not planning on getting crazy with the car anymore (or at least for now). Maybe run a 14b or 16g on 10 - 15 lbs of boost. Are those Exedy OEM replacements decent?
 

SouthCaliVR4

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It is less about the press of the clutch than the clutch switch, if you have a big clutch & still push the pedal down when you start the car there is no oil flow to protect the thrust brg's. run any clutch you like just disable the clutch switch & break the habit of pushing it in when you start the car.

This is not a universal opinion but it has undeniable logic in my mind.

I have a center force but have been unimpressed with it's holding power, others are sure to chime in on better more current rec's
 

curtis

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Drop the exhaust , transfer case and the pan. Push in the cltch and use a long bar, stick of 2x4 to hold it in then go out under the car and use a pry bar and force the crank back and forth. If it moves its walking. You can simply drop the center main cap and change that bearing and call it a day with out pulling the motor. Its a bitch but can be done.
 
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