[ds968]

a tensioner design flaw causing everyone's lower pads to wear unevenly seems like a plausible explanation .. [img]style_emoticons/<#EMO_DIR#>/huh.gif[/img] sheesh, if they had to screw up, why couldn't the defect cause the upper pad to be the one with accelerated wear so people can at least see it on inspection [img]style_emoticons/<#EMO_DIR#>/dry.gif[/img] f'n Porsche !

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[xrad]

seems like if the exhaust cam is turning clockwise (and since 'chains' don't 'push' very well) more stress is put into tension on the lower half of the chain as it tries to pull the intake cam(especially during the 'advancing' stage). This could cause uneven wear. Also why the teeth tend to curve towards the clockwise direction.

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[rustech]

<!--quoteo(post=75788:date=Jul 19 2009, 01:09 PM:name=xrad)-->QUOTE (xrad @ Jul 19 2009, 01:09 PM) <{POST_SNAPBACK}><!--quotec-->seems like if the exhaust cam is turning clockwise (and since 'chains' don't 'push' very well) more stress is put into tension on the lower half of the chain as it tries to pull the intake cam(especially during the 'advancing' stage). This could cause uneven wear. Also why the teeth tend to curve towards the clockwise direction.<!--QuoteEnd--><!--QuoteEEnd-->

I think what you described is the largest part of it. Other factors might be where the pads tend to be located (distance) relative to the midpoint (cam to cam) during retarded vs advanced timing and at what RPM. I'm sure there's more wear the further from the midpoint as well as at high RPM.

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[GREYGHOST]

last weekend I started to do a t/belt. got everthing ready. had a new v/cover gasket. pulled it up to inspect the pads. looked at them they did not seem bad,
but the spockets are toast it will have a tooth then jump three or four nubs.
was running just fine a little over 200K on it.

well I just stopped there and coming up with a game plan. I have a used motor but it has the mounting surfaces for the ALt/a/c bracket broken off. Do I build up the spare motors, head. and build the good bottom end.

thanks Rob

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[jlm968]

My $0.02 worth, is that you can change the parts that need changing in order to get the car going, and plan/budget a rebuild the spare engine over the next few months or through winter. You can use the cams from the spare engine. Other parts like the timing chain and pads you can buy new, cheap compared to finding cams.

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[gbarrier]

Amazing the difference. At 100K when I bought mine I pulled the cover to find half the sprocket teeth missing. Pads had minimum wear.

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[Lear35A]

Maybe this thread is dead, but what the heck.
A lot of the above posts mention their top pads looking ok, so they just buttoned it up again. As other posts have mentioned, the bottom pad wears a lot more. My bottom one has much deeper grooves and pitting (after 100K mi). The rail on the left is the bottom one.

BTW, anyone out there with the compression tool that would let me beg, borrow or rent?
Lance

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[Ryan]

Rob,

RS Barn can re-sprocket your cams. Give Pete a call.

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[RS Barn]

What is really interesting is the variocam is lowered most of the time while driving. This should reduce the pad wear and even it out.
It just doesn't hapen that way.
BTW 944s and S-2 have different tensioners and a higher failure rate.
Pete

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[marazas]

Hi!
I got scared after reading all those post so I started looking through older receipts. My car is at 100K right now and these receipts (quite a service):
http://farm5.static.flickr.com/4047/450338...b75e5913d_o.jpg
http://farm3.static.flickr.com/2755/450338...ca7c5c738_o.jpg
looks like the pads are changed. Is there any reason for opening and performing an inspection? The receipts are from less than 30K ago and I guess I need to replace gaskets if i open to inspect, right?

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[DaveN]

You don't need to replace the valve cover gasket to inspect. I just clean mine well and put a film of hi temp RTV on the faces before re-assy. Just watch the torque on the cover bolts, very little required - 5 ft/lbs I believe.

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[marazas]

Thanks! Maybe I should do the inspection anayway. It should probably not be needed if the receipt is right and everything was replaced..

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[dwsjung]

I have 61K on my 968, and thinking about having the pad variocam pad replaced (chain if required).  Anybody know what I can expect to pay a shop to do this work ? 

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[williamoss]

Prior to going the small claims route I would speak to an attorney. Here in Oregon if the defendant wants to he can ask to have the case moved up to a higher level of small claims court where attorneys are required I believe. It might be prevalent to have an attorney file the motion in case there is a class action here. The main problem is in a class action is that there is not a large class. Since there were only about 4500 cars imported to the USA and how many are still on the road today, etc etc. it is a small class. A lot of attorneys do not cost anything for the initial discussion.

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[Sculler]

dwsjung.


I bought my car last year with 55,000 miles. After retrieving the car I found the bottom pad to be in very poor condition. I would highly recommend that you get this work done and make sure it's done by a shop that has experience with 968 belts and Variocam. Next thing is, you might as well have water pump replaced at same time.


Oh the joy of owning an old Porsche.

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[williamoss]

I just spoke to my mechanic regarding the changing of both the top and the bottom pads . His opinion, and he has not had to do this job for a few years, was that the bottom pad is not sold separately.  If that has gone bad one has to buy the entire Chain Adjuster (part # 944 105 201 AX). Is this true? Does anyone have a supplier of both top and bottom pads? Or perhaps another manufacturer of a remanufactured Chain Adjuster brand. If so what is the name of the supplier and what is the part number of that supplier? I called Sunset and the part # I mentioned above is a remanufactured part which costs $2,000.00. Porsche no longer has new parts, only a remanufactured one, and no pads. You have to buy the whole thing. The timing chain is cheap at $33.00.

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[Sculler]

Just looked up my invoice from last year. Pads were $44.00 a piece. Chain $46.00. Gasket and seal $125.00. Labor $787.50. Total invoice $1,084.51.


These are maintenance items so got to believe they are still available. I would look for new shop.

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[williamoss]

so you were able to change both the top and the bottom pads? I ask because according to Sunset they agreed that only the top pad was changeable, while the bottom one was not and you had to buy the whole unit.

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[Sculler]

Yes you can change bottom and top. Maybe try Pelican for a different opinion.

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[vliegwielolaf1234]

top and bottom are the same pads on the 968 .

S2 has different bottom pad

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