Modify PK Tensioner for Black edition
#61
Nordschleife Master
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Red Dog to Blue Squirrel, Red Dog to Blue Squirrel, the Cardinal has received the package - I repeat the Cardinal has received the package.
Thought the levity would be good here and maybe crack a little smile on some.
The Dark Side is growing strong here.
Thought the levity would be good here and maybe crack a little smile on some.
The Dark Side is growing strong here.
#62
Former Vendor
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BTW. The fellow who phoned asking about the transmission gave me a slightly different story. At first you didn't know it was one of the fellows whom I have done tons of work for, he asked about a guarantee on the transmission and you would offer none. A brand new box you claim, and to stand behind your products, but you wouldn't guarantee that it would not even work on arrival. Then you found out that I would be installing it and you gave him a rant. He knows me well, and the work I do. He said he wouldn't buy anything off of you after how you behaved on the phone.
Again you distort facts, and purposefully twist things around to suit your narrative.
You have one thing partially correct. He did ask for a warranty. I did not dismiss this request, out of hand, until I was told you were doing the work.
There was never a phone call.
There was never a rant.
I sent your customer a VERY short email telling him I did not trust you and would prefer to not be involved.
End of story.
Now, who is it that twists things around to suit their own point?
Here's why I can't warranty the thing, if you are installing it or working on it, has your gearshifter in it.
Your idiotic gearshifter mounts solid to the chassis, while the engine and transmission is able to move back and forth in the chassis. Every time the engine moves back and forth, the internal shift forks (held solid by the chassis mounted shifter) act like a portable lathe in the sliders. I don't know how long that takes to those parts....but it will and is ruining those parts on every single car that has your gearshifter.
That's just basic, irrefutable engineering common sense!!!!!
How do I warranty that?
Porsche attached the gearshifter to the torque tube so it moves with the engine and transmission, so it wouldn't force the shift forks for and aft when the engine and transmission moved fore and aft!!!!!
Pretty much everyone, in the entire world, knows not to rest their hand on the gearshift lever....for this very reason. With your gearshifter, they don't have to worry about this.....you're ruining their transmission for them.....every single time their cars hits a bump and the engine and transmission moves back and forth!
How do I warranty that?
Last edited by GregBBRD; 07-07-2014 at 03:30 PM.
#63
Former Vendor
#64
Inventor
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Business must be r-e-a-l-l-y slow if you have time to work on these colorful posts all day long.
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#65
Rennlist Member
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I’m rolling up on 5 years on mine and this is the first I’ve heard of it – so although not the original intent of the thread, I’m personally glad it got there in the end.
#66
Inventor
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The flat head bolt, not lettered, behind the tensioner/damper (apparently) snapped after the flange head bolt(s) became loose, allowing the bracket to move fore and aft.
No other flat head bolts have been reported broken or loose.
FWIW, Jim C's flat head bolt was still tight after >70,000(!) miles of use.
No other flat head bolts have been reported broken or loose.
FWIW, Jim C's flat head bolt was still tight after >70,000(!) miles of use.
#67
Drifting
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Ken, have you looked into Shoulder Bolts instead of using the screws only? This will fit better in the pivot hole (hardened precision shoulder) then the bracket could have a tight fit counterbore on the shoulder bolt diameter and a thru hole with a nut (fixture plate in the picture would be a through hole with nut instead)? The bottom of the counterbore would need to be a set depth for the correct fit when tightening the nut and the diameter would set the perpendicularity. Just a suggestion
http://www.mcmaster.com/#shoulder-bolts/=sqjec8
http://www.mcmaster.com/#shoulder-bolts/=sqjec8
#68
Racer
Thread Starter
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I must say I had no idea what kind of ****-storm I'd be raising by asking about the design change. I just spent 20 minutes reading a personal argument that didn't educate me one bit, really... except that now I know there's drama between two well-respected members of the community.
Hopefully mods can go through this thread and remove all the irrelevant posts (including this one)... so that future rennlisters can find it useful and not have to sort through all the crap to find quality content.
I asked what modifications had to be done to turn my gold bracket into the 'black edition', and got that answer on page 1 of this thread. A lot of people use Ken's tensioner system and it's been installed on many many cars without issue. I'm sure that Ken or Roger can supply that information, though I'm not asking for it. I am still happy to install this product on my own car.
The engineering behind the design is sound, even if it took a few versions to get where it is today. I've RARELY heard of "Part V 1.0" being perfect... and anyone reading this who is also an engineer can attest to that. I fully expect the design to change further in light of this thread and and any FMEA that occurs with time, and have no issue with it. I don't see why anyone else would have a different opinion or expectation. As has been said before, any time one decides to purchase a aftermarket part, there is risk involved. Jim Corenman's response (#53 in this thread) is probably the best one so far.
Hopefully mods can go through this thread and remove all the irrelevant posts (including this one)... so that future rennlisters can find it useful and not have to sort through all the crap to find quality content.
I asked what modifications had to be done to turn my gold bracket into the 'black edition', and got that answer on page 1 of this thread. A lot of people use Ken's tensioner system and it's been installed on many many cars without issue. I'm sure that Ken or Roger can supply that information, though I'm not asking for it. I am still happy to install this product on my own car.
The engineering behind the design is sound, even if it took a few versions to get where it is today. I've RARELY heard of "Part V 1.0" being perfect... and anyone reading this who is also an engineer can attest to that. I fully expect the design to change further in light of this thread and and any FMEA that occurs with time, and have no issue with it. I don't see why anyone else would have a different opinion or expectation. As has been said before, any time one decides to purchase a aftermarket part, there is risk involved. Jim Corenman's response (#53 in this thread) is probably the best one so far.
#69
Rennlist Member
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Remember that the thru-hole for this early bracket was 8.0 mm, which is a tight fit for a M8 screw. So it is basically acting as a dowel pin, and the forces on the fastener were primarily shear. Fasteners are pretty strong in shear.
I believe that the later brackets all have 9.0mm thru-holes for the countersink. If that is correct then that is a different situation: The combination of the incorrect countersink (making contact only at the top edge) and the oversize hole means that the fastener is stressed in bending, and not shear. Fasteners don't like bending, and tend to fatigue and break. Correcting the countersink reduces the lever-arm and the bending stress but I believe that the 8.0mm thru-hole was a better choice.
Last edited by jcorenman; 07-08-2014 at 02:17 PM.
#70
Racer
Thread Starter
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I'll measure the hole diameter on my gold bracket tonight, provided that I remember to do it.
For reference, I purchased my tensioner kit in October, 2013... and I'm just finally getting around to installing.
The end tank on my radiator cracked, prompting its replacement. No better time to do the timing belt than when the radiator is already out. Oh, the radiator is out? Well, I might as well do the oil pan gasket and motor mounts. Might as well remove that air pump that's been idle since the x-pipe went in. Hmm... that power steering rack could use new bushings and gators. And so it goes...
For reference, I purchased my tensioner kit in October, 2013... and I'm just finally getting around to installing.
The end tank on my radiator cracked, prompting its replacement. No better time to do the timing belt than when the radiator is already out. Oh, the radiator is out? Well, I might as well do the oil pan gasket and motor mounts. Might as well remove that air pump that's been idle since the x-pipe went in. Hmm... that power steering rack could use new bushings and gators. And so it goes...
#71
Instructor
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I'm fitting the Pk black this week. Do I use thread locker blue on the pulley bolts? I bought red for some reason, but common sense say id need to remove these at some point, eg after 100k miles of use on a pulley bearing?
Cheers, JB
Cheers, JB
#72
Rennlist Member
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Just got through reading this lot, I've gone from totally happy with the PKT to almost to scared to run the car.
I've had Ken's PKT fitted since 2009 and run 20,000 miles, I have not seen the email Roger sent out, as a coincidence I had one of the belt covers off last Thursday to check the belt and pulleys, all seemed fine.
Not sure what to do next, are the early PKT's OK, do I need to replace any hardware, i. e. bolts.
I've had Ken's PKT fitted since 2009 and run 20,000 miles, I have not seen the email Roger sent out, as a coincidence I had one of the belt covers off last Thursday to check the belt and pulleys, all seemed fine.
Not sure what to do next, are the early PKT's OK, do I need to replace any hardware, i. e. bolts.
#73
Rennlist Member
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928sRus sent out an safety advisory earlier this year to ALL customers on our system that purchased a PKensioner bracket or system this was also followed up with a more detailed appraisal for those that requested it.
If you did not receive it (some did end up in spam as it was a mass mail) just contact me roger@928srus.com and I will be happy to supply it.
Actions requested ----
Visually & physically check the system for any loose bolts - if bolts are found to be loose please report back (none reported at all)
A replacement countersunk bolt supplied free of charge and to be fitted when next convenient to do so.
For those that requested it a free upgrade to the "Black" system consisting of the nuts, bolts and instructions to make the change.
AT NO TIME HAS THERE BEEN A COVER UP of any type at any time. The issue has been discussed everywhere in a free way and customers and potential customers have a right to decide for themselves what they wish to do.
If you did not receive it (some did end up in spam as it was a mass mail) just contact me roger@928srus.com and I will be happy to supply it.
Actions requested ----
Visually & physically check the system for any loose bolts - if bolts are found to be loose please report back (none reported at all)
A replacement countersunk bolt supplied free of charge and to be fitted when next convenient to do so.
For those that requested it a free upgrade to the "Black" system consisting of the nuts, bolts and instructions to make the change.
AT NO TIME HAS THERE BEEN A COVER UP of any type at any time. The issue has been discussed everywhere in a free way and customers and potential customers have a right to decide for themselves what they wish to do.
I'm going in asap to check both cars and advise the folks who have had the PKT system fitted by myself. (total of 5 IIRC)
A note for all; I have one of the very original PKTs on my S4 that Ken sold direct to myself..........many many years ago and 10s of thousands of kms with zero issues.
Glad to hear GM wasn't involved in the recall
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#74
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All three M8 fasteners were snug, but not torqued-to-20NM-and-left-in-place-for-years "tight". There was none of the typical "pop" as they came loose, as is typical for steel fasteners threaded into aluminum. That may mean nothing, or may be significant--I do not know.
The combination of the incorrect countersink (making contact only at the top edge) and the oversize hole means that the fastener is stressed in bending, and not shear. Fasteners don't like bending, and tend to fatigue and break. Correcting the countersink reduces the lever-arm and the bending stress but I believe that the 8.0mm thru-hole was a better choice.
The combination of the incorrect countersink (making contact only at the top edge) and the oversize hole means that the fastener is stressed in bending, and not shear. Fasteners don't like bending, and tend to fatigue and break. Correcting the countersink reduces the lever-arm and the bending stress but I believe that the 8.0mm thru-hole was a better choice.
The really strange thing about all of this is the idea that these details are even remotely important in relativity to the fact that you open up almost ANY 928 that has NOT had Greg Brown or Sean or... Some of us in it previously - and you will not see an OEM tensioner in good shape. Broken boots, no oil, worn pulleys, out-of-alignment arms, bolts stripped, etc.
I have had 11 (12?) 928s. How many has Mark Seen? Most people don't know squat about these cars, and even less about what is going on with these OEM tensioners. For the perceived faults, the Porken unit works fine for what its intended to do, and is also quite a bit cheaper. There are four big bolts holding the damn thing on. We all have "agendas" - or we wouldn't be human. But the discussion of where the shoulder is hitting on the bolt (Above) in relation to how the OEM tensioners are treated on 93% of the cars (that percentage not worked on by the experts here - and we are experts in many ways compared to the proletariat) is silly. It really is.
Its all very connected. Why does the 928 have a bad name? (Many people who know 928s as bad don't even know about us on this forum, so that's not a reason for a bad name either) The belt and the electrical. Is that a real reason? Not really - not when you understand the systems. The belt system is stupid. Sure - it works, but only when cared for more than most would EVER care for that system on a car.
#75
Three Wheelin'
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I have it, seems like a great design. I'm sure the factory one works well but I would rather have this on my car.
I will say the main part is to tighten that flush mounted allen screw first which has been talked about extensively on this forum.
This system reminds me of the 911 oil fed tensioners which I am most familiar with that sit behind the cam covers and tension the chain on both sides. It works very well and is always consistent and many people have upgraded this on their older 911's that were pre-tensioner equipped. Tension on the belt (in the 928) seems adequate as well and not too much. I would recommend this to anyone.
The last thing I will say... after purchasing my 928 (first one for me) I have been on this forum many times. In the past I was mainly on the 911 forums as I've rebuilt and restored older turbos over the years and still have one today as my avatar shows. Everything on this board including the people who own and the people who sell have been fantastic including everyone bickering on this thread. The only problem is the fighting back an forth... call each other up and discuss it, come to an agreement and post it then let the public decide. The suppliers going back and forth has got to stop... I shy away from these threads now because reading it all makes me sick.![banghead](https://rennlist.com/forums/graemlins/banghead.gif)
![banghead](https://rennlist.com/forums/graemlins/banghead.gif)
![banghead](https://rennlist.com/forums/graemlins/banghead.gif)
![banghead](https://rennlist.com/forums/graemlins/banghead.gif)
My .02... Bryan
I will say the main part is to tighten that flush mounted allen screw first which has been talked about extensively on this forum.
This system reminds me of the 911 oil fed tensioners which I am most familiar with that sit behind the cam covers and tension the chain on both sides. It works very well and is always consistent and many people have upgraded this on their older 911's that were pre-tensioner equipped. Tension on the belt (in the 928) seems adequate as well and not too much. I would recommend this to anyone.
The last thing I will say... after purchasing my 928 (first one for me) I have been on this forum many times. In the past I was mainly on the 911 forums as I've rebuilt and restored older turbos over the years and still have one today as my avatar shows. Everything on this board including the people who own and the people who sell have been fantastic including everyone bickering on this thread. The only problem is the fighting back an forth... call each other up and discuss it, come to an agreement and post it then let the public decide. The suppliers going back and forth has got to stop... I shy away from these threads now because reading it all makes me sick.
![banghead](https://rennlist.com/forums/graemlins/banghead.gif)
![banghead](https://rennlist.com/forums/graemlins/banghead.gif)
![banghead](https://rennlist.com/forums/graemlins/banghead.gif)
![banghead](https://rennlist.com/forums/graemlins/banghead.gif)
My .02... Bryan