928 Crank Thrust bearing, The Weakest Link
06-25-2007, 11:06 PM
#46
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Originally Posted by FlyingDog
The three slaves (two cars) I've pulled out all had significant force pushing on the fork and little or no preload on the master.
Originally Posted by Steve Cattaneo
This is why the master cylinder PUSH rod (not the salve cylinder push rod) must be adjusted correctly; preloading the push rod by one turn, will position the master cylinder push rod to were it will barely touch the master cylinder piston, any more (not adjusted properly) would pressurized the salve cylinder, in turn disengaging the clutch, almost like riding the clutch.
I wonder how much of the front-side TB wear on 5-speeds is the result of driver's starting the motor with the clutch disengaged and/or keeping the clutch disengaged for long periods at idle (when oil pressure is low) while at stop lights?
06-25-2007, 11:22 PM
#47
I remember on the 89 that the clutch was so heavy I rarely left it in if I didn't need to shift.
06-26-2007, 08:50 PM
#48
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Originally Posted by worf928
IIRC it takes some force to get the slave in place, but once it is in place the force necessary to keep it there is only a few pounds.
07-02-2007, 08:06 AM
#49
What are the tell-tale signs of impending tbf? My GT has an aftermarket hd clutch, fitted by the PO, and occasionally makes a whirring sound when I'm releasing the clutch. I only notice it when pulling away with a cold engine - can't tell if there's any noise or not once on the move.
The sound 'goes away' after a few miles.
Graham
'84 Strosek auto
'90 GT
The sound 'goes away' after a few miles.
Graham
'84 Strosek auto
'90 GT
07-02-2007, 09:40 AM
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If there's any doubt whatsoever, I'd check it out. The consequenses of TBF warrant it unless the noise is totally obvious something else. High stakes gamble with possible TBF.
H2
H2
07-03-2007, 03:48 AM
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I may be experiencing TBF; for the purpose of my inquiry let's assume that is my problem. Would it be best to replace the engine altogether or rebuild? I'm asking from the cost perspective and durability. I realize that cost is relative to the level of damage and what specific parts/labor would be needed, so let's just assume 50% of TBF before engine seizing (sorry if that's too vague). I also realize durability is relative to the rebuilder's talent.
I've been recommended by one of the Big 3 to replace the engine and that there aren't too many success stories out there for a 928 rebuild after TBF. He expressed concerns about bearing sleeve thickness, bearing surfaces/clearances, building up/re-machining surfaces, etc. I would have to rely on someone else to complete the work as I am not as mechanically inclined as many of you guys. To that point, is there a particular shop/person that you could suggest to perform a successful rebuild that I could trust if that is your recommendation? Any ideas as to where I might find a good 90-91 engine if replacing the motor is your recommendation?
Thanks,
I've been recommended by one of the Big 3 to replace the engine and that there aren't too many success stories out there for a 928 rebuild after TBF. He expressed concerns about bearing sleeve thickness, bearing surfaces/clearances, building up/re-machining surfaces, etc. I would have to rely on someone else to complete the work as I am not as mechanically inclined as many of you guys. To that point, is there a particular shop/person that you could suggest to perform a successful rebuild that I could trust if that is your recommendation? Any ideas as to where I might find a good 90-91 engine if replacing the motor is your recommendation?
Thanks,
