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Old 09-21-2007, 12:03 AM   #1
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Default Thrust bearing Issue

I need to figure out the problem before I put another motor in. I need you turbo gurus to help me out here.

http://forum.miata.net/vb/showthread...18#post2706018
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Old 09-21-2007, 12:10 AM   #2
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Won't having too much preload on your clutch from not adjusting it cause your throwout bearing to go bad prematurely? Did you adjust it after clutch install?
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Old 09-21-2007, 12:17 AM   #3
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Quote:
Originally Posted by cjernigan View Post
Won't having too much preload on your clutch from not adjusting it cause your throwout bearing to go bad prematurely? Did you adjust it after clutch install?
Adjust the clutch pedal? I didn't adjust anything.
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Old 09-21-2007, 12:22 AM   #4
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You installed your ACT and didn't adjust the clutch pedal?
Your clutch could be partially depressed all the time if not. Which would cause premature failure of the TOB.
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Old 09-21-2007, 12:23 AM   #5
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I don't know I bought the car with the ACT clutch installed.
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Old 09-21-2007, 12:32 AM   #6
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Adjust the bolt out so that the pedal has slack for sure, then retighten the bolt to where it just touches the master cyl shaft so you know it doesn't have any preload.
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Old 09-21-2007, 12:33 AM   #7
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Any questions why my thrust bearing keep going bad?
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Old 09-21-2007, 12:34 AM   #8
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Excuse my confusion, i was thinking throw out bearing.
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Old 09-21-2007, 12:43 AM   #9
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well there was a thrust bearing issue for 99 motors that was solved. Its only on cars with certain vins...check here.

http://www.miata.net/solo/99miatathr...ngfailure.html
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Old 09-21-2007, 12:49 AM   #10
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this is a 91 long nose crank motor.
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Old 09-21-2007, 01:39 AM   #11
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oh, me being the owner of an NB thats how my mind works. Sorry
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Old 09-21-2007, 11:00 AM   #12
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It has long been said a heavy pressure plate causes premature thrust failure (in the DSM world where "crankwalk" is common). I don't know if I totally believe in that but I'd only ever run as much clutch as I need.
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Old 09-21-2007, 06:27 PM   #13
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anybody?
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Old 09-21-2007, 06:42 PM   #14
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Anybody WHAT? You have gotten a whole host of different possible answers here and on M.net. What the hell do you want? It could have failed for any number of reasons. Without a full failure analysis nobody here is going to be able to give you any better guesses, and even then a lot of people are still going to say "it's the clutch."

Who assembled the engine in question and did they properly install the crank and align the thrust bearing? Was assembly lubed used? Was the oil pump primed before the first startup?
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Old 09-27-2007, 05:06 PM   #15
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Is a O2 Clamp must to have if I'm only using bipe acu?
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Old 09-27-2007, 06:03 PM   #16
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Actually having the clutch preloaded CAN cause premature thrust wear. Think about it. If the slave is pushing the clutch assembly that's bolted to the crank, then the entire assembly is pushed against the thrust bearing. So every time the car is started, the crank bearing face at the thrust, is pressed against the bearing w/o any oiling.
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Old 09-27-2007, 09:05 PM   #17
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Quote:
Originally Posted by m2cupcar View Post
Actually having the clutch preloaded CAN cause premature thrust wear. Think about it. If the slave is pushing the clutch assembly that's bolted to the crank, then the entire assembly is pushed against the thrust bearing. So every time the car is started, the crank bearing face at the thrust, is pressed against the bearing w/o any oiling.
So do I need to adjust the clutch pedal?
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Old 09-27-2007, 09:15 PM   #18
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yes, like cj said- check and make sure there's "slack" or "free play"
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Old 09-27-2007, 10:12 PM   #19
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so move the nut for the adjusting clutch pedal until it barely touch the clutch switch right?
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Old 09-27-2007, 10:36 PM   #20
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focus on the free play of the pedal- you should have at least an 1/8" of movement before you actually have the pedal assembly engage the slave (feel the resistance of hydraulic pressure)
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