Thrust Bearing Failure
#17
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The 4.7 seems to lack the torque needed to pull the driveshaft from the flexplate clamp. However if the trans or torque tube has been removed it is POSSIBLE to preload the flexplate if done incorrectly. But thrust bearing failure is almost always an 87 and newer automatic problem. Plus the early cars had shims and a snap ring installed to prevent movement when new, may or may not still be there.
#18
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Every 928 automatic owner should check for drive shaft pullout and their crankshaft end play.
From the research we've done and from the customers we have serviced over the years, it can hit any year 928 automatic regardless of engine type or suspected service history.
Cheers,
From the research we've done and from the customers we have serviced over the years, it can hit any year 928 automatic regardless of engine type or suspected service history.
Cheers,
#19
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Manual cars should also be checked as the drive shaft migrates in those as well. Starting with a loose rear coupling bolt, the shaft migrates forward and the bolt rides up on to the splines. When that far forward the stub shaft can be rammed into the pilot bearing in the end of the crank, and thus exerts some pressure on the thrust bearing. My 82 was applying constant pressure to the crank ... but luckily endplay was still OK.
It's much less likely on a manual ... but I don't think they're necessarily immune from damage if left long enough. Why take the risk ... check them all including manuals.
It's much less likely on a manual ... but I don't think they're necessarily immune from damage if left long enough. Why take the risk ... check them all including manuals.
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#21
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I think it's a bit overborad to rag on a mechanic for following the factory guidelines. If we take this attitude, the 928 will become a DIY only car since we will eventually eliminate every good 928 mechanic after the two Greg's and a couple of others retire or get sick of us.
Fact is, the majority of 928's are serviced at indipendant shops with shop owners who have to keep track of thousands of vintage foreign cars. To expect them to know every single nuance of the 928 is absurd.
We should be helping to educate these shops, not wite them off as worthless.
Fact is, the majority of 928's are serviced at indipendant shops with shop owners who have to keep track of thousands of vintage foreign cars. To expect them to know every single nuance of the 928 is absurd.
We should be helping to educate these shops, not wite them off as worthless.
#22
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We still don't know if it's an auto or 5 speed, although as pointed out above 5sp's are potential victims too, and in your (pretty impressive, considering when you got it) list of maintenance completed, I don't see fuel lines. Absolutely critical, which you prob know from hanging out here. And checking the flex plate if it is an auto is duck soup, NOT a WYAIT.
Last edited by M. Requin; 05-04-2012 at 04:46 PM. Reason: ignorance
#23
Captain Obvious
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I think it's a bit overborad to rag on a mechanic for following the factory guidelines. If we take this attitude, the 928 will become a DIY only car since we will eventually eliminate every good 928 mechanic after the two Greg's and a couple of others retire or get sick of us.
Fact is, the majority of 928's are serviced at indipendant shops with shop owners who have to keep track of thousands of vintage foreign cars. To expect them to know every single nuance of the 928 is absurd.
We should be helping to educate these shops, not wite them off as worthless.
Fact is, the majority of 928's are serviced at indipendant shops with shop owners who have to keep track of thousands of vintage foreign cars. To expect them to know every single nuance of the 928 is absurd.
We should be helping to educate these shops, not wite them off as worthless.
#24
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Reminds me of my 944S and Zimbrick Porsche in Madison. I brought the car in for an oil change and to have them replace the cam chain & tensioner. I was told by the head mechanic the chain / tensioner were not wear items, it would be a waste of money to do.
Later that year my chain broke
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#25
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Hello ALl
Buchanans in AUstralai , who make their living from serviceing these cars , will argue that the thrust bearing migration will not occur if the engine oil is the right grade and the torque tube clamp bolts are torqued correctly and replaced when disturbed , be interesting if your mechanic is of the same opinion, as they are both trained Porsche mechanics, to date buchanans will state that they have not seen a car with this problem , that they have serviced . SO I would not be too fast to dismiss them , as there is a lot of experience there .
Buchanans in AUstralai , who make their living from serviceing these cars , will argue that the thrust bearing migration will not occur if the engine oil is the right grade and the torque tube clamp bolts are torqued correctly and replaced when disturbed , be interesting if your mechanic is of the same opinion, as they are both trained Porsche mechanics, to date buchanans will state that they have not seen a car with this problem , that they have serviced . SO I would not be too fast to dismiss them , as there is a lot of experience there .
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#26
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The Mechanic is not 100% wrong, but he should not discourage you from checking the endplay, however this sounds like a 'lazy' mechanic.
You can do this (and should) yourself. Its not 'hard', just difficult (I had to remove my exhaust to get the lower bellhousing cover off.).
You can do this (and should) yourself. Its not 'hard', just difficult (I had to remove my exhaust to get the lower bellhousing cover off.).
#27
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Leave the last two bolts that live under the exhaust off when you remove the bell housing cover. You don't need them. If you don't want to take the exhaust off, you can loosen them, then sawzall them off and unscrew the stub.