[928uk] Thrust Bearing Failure

[Paul R Smith]

>    
You could argue that a 5W-40 is not specified as an alternative in the 
'91 driver's manual, but the reality is that the reason for that is that 
it probably didn't exist then. Porsche's current approval list contains 
lots of 5W-40 oils, so they could validly say that that they used a 
Porsche approved oil, and who are we to argue. A judge isn't going to 
accept that we know more than Porsche!

Smiffy

> Thanks Smiffy - Helpful advice as always.
> I never specified the oil - they chose 5W-40 - but neither did I ask 
> them to check thrust bearing clearance.
> Having said that, when I raised the subject of flex plate they told me 
> that they were very familiar with the problem, which also affects 968 
> tiptronics.
> Cheers.
> Graham.
>
>     -----Original Message-----
>     *From:* 928uk-bounces at lists.928.org.uk
>     [mailto:928uk-bounces at lists.928.org.uk] *On Behalf Of *Paul R Smith
>     *Sent:* 20 February 2012 00:47
>     *To:* 928uk at lists.928.org.uk
>     *Subject:* Re: [928uk] Thrust Bearing Failure
>
>     TBF is caused when the pressure from the flex plate exceeds the
>     film strength of the oil, so thin oil makes it more likely. If the
>     engine had 10W-40 in it, did they chose that, or did you?
>     Did they check the thrust bearing clearance, or just release the
>     flexplate pre-load?
>     Did you ever ask them to check the clearance? (This is where a 928
>     specialist is going to know what to do, but a "porsche specialist"
>     probably won't.)
>
>     A loose pinch bolt certainly suggests shoddy work, but didn't
>     cause the failure.
>
>     Cam sprockets wear. They will wear faster if the belt is
>     over-tensioned or loose. Was the belt tension checked, or just a
>     guess based on the wear. It the tension was checked, there should
>     be a figure quoted.
>
>     ATF is an acceptable substitute for gear oil "if the correct grade
>     is not available", so ATF in the diff implies extreme laziness or
>     incompetence.
>
>     I would suggest finding a few articles on flexplate TB checking,
>     print them out and show them to the garage. This will show them
>     that it is common knowledge amongst specialists that it is
>     important to check the TB clearance.
>     When they have had time to absorb that, point out how much money
>     you have paid them over the years, and ask them if they would like
>     to make a contribution to the repair replacement of your engine.
>
>     If you went to court, you would have a very difficult time proving
>     that anything they did caused the TBF or that anything they didn't
>     do could have been expected to have been done.
>
>     Smiffy
>
>
>     On 20/02/2012 6:19 a.m., go928 wrote:
>>
>>     Late last year my S4 auto suffered terminal tbf - the engine is
>>     probably a write-off.
>>
>>     Briefly, I've owned the car about 10 years, covering about 6,000
>>     miles a year.  She has 130k on the clock.  Throughout the last 10
>>     years she has been maintained and serviced annually by the same
>>     firm and a flex plate check has been specified at each service. 
>>     Over the last couple of years I have had a series of problems
>>     with difficulty starting, stalling and uneven running.  She has
>>     been back to the specialist on a number of occasions and fuel
>>     pump, MAF and ISV among other things have all been replaced. 
>>     Each time the immediate problem has been resolved, but the car
>>     was not running quite right, although it was hard to say
>>     precisely why.  I now suspect this was early symptoms of the
>>     pending failure.
>>
>>     My view is that the Porsche specialists who look after the car
>>     should bear some responsibility, but they do not agree and have
>>     washed their hands of my situation.  Maybe I am not being as
>>     objective as I should be so I would welcome any thoughts.
>>
>>     My reasons for blaming the firm who looked after the car are:
>>
>>         * Everything I have read about tbf seems to suggest it is
>>           unheard of where the flex plate has been checked and
>>           released regularly.
>>         * The engine finally seized only about 2,000 miles after the
>>           last service/flex plate check.
>>         * When the tbf was diagnosed (by a different firm) the pinch
>>           bolt was only finger tight.
>>         * The firm admit that they do not change the pinch bolt when
>>           they check the flex plate.
>>         * The cam belt rollers are damaged due to overtensioning of
>>           the belt.  (As they have changed the cambelt twice since I
>>           acquired the car, to my mind, even if they didn't cause the
>>           damage they should have spotted it and changed the rollers).
>>         * ATF in the diff.
>>
>>     The last two points have no direct bearing (ha ha) on the thrust
>>     bearing failure, but do indicate a questionable level of care.
>>
>>     My questions:
>>
>>         * Is it fair to pursue the firm for a contribution towards
>>           the cost or should I accept (as they claim) that the thrust
>>           bearing can fail at any time, even if the flex plate is
>>           regularly checked?
>>         * If I do have a claim, any thoughts on how best to get them
>>           to do the decent thing?  I will take them to court if
>>           necessary but would prefer to avoid all the hassle if
>>           possible.
>>
>>     Thanks in advance.
>>
>>     Graham
>>     (91 S4 auto)
>>
>>
>>     _______________________________________________
>>     928uk mailing list
>>     928uk at lists.928.org.uk
>>     http://lists.928.org.uk/cgi-bin/mailman/listinfo/928uk
>>        
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.928.org.uk/pipermail/928uk/attachments/20120220/751a2866/attachment.htm>