wjk_glynn

Done.

jjrichar

Below are a few extra videos for people if interested.

I re-published the rear cover video as I came across some new information about the sealed bearings (I can't edit the post above unfortunately), so I made a video just about these bearings to explain what seems to be involved to find replacements as well as another covering the rear casing with the bearing info.

Also made a video digging more deeply into the valve body and one on the clutch section electrics.

jbaker136

[QUOTE=jjrichar;18470295]Below are a few extra videos for people if interested.

I re-published the rear cover video as I came across some new information about the sealed bearings (I can't edit the post above unfortunately), so I made a video just about these bearings to explain what seems to be involved to find replacements as well as another covering the rear casing with the bearing info.
/QUOTE]
Another great video. I can see how those bearings could be a future service item but I wonder at what mileage. I have 5 PDK cars from 997.2 to 981 Clubsport with mileage as high as 60k with many track seasons and zero issues on any of the transmissions. My guess is that those bearings would be good for 150k plus miles assuming good maintenance practices.Even so, it's great to know that if they do need replacement it's $200 or less in bearings and machine shop.

Jeff

toddlamb

We haven’t seen bearing failures in any boxes yet but they are replaced when we do a full PDK rebuild as preventative maintenance.

jjrichar

/QUOTE]
I can see how those bearings could be a future service item but I wonder at what mileage. I have 5 PDK cars from 997.2 to 981 Clubsport with mileage as high as 60k with many track seasons and zero issues on any of the transmissions. My guess is that those bearings would be good for 150k plus miles assuming good maintenance practices.
[/QUOTE]

I have no idea how long they would be good for. I expect they are very high quality, but knowing how long Porsche sports cars stay on the road there will be the need for replacement at some stage. I'm not a bearing expert in any form, but I could guess that a lot of track time at high RPM would reduce the lifetime.

As stated by toddlamb above it doesn't seem to be something that is near term problem, which gives me some peace of mind. They clearly see a lot of these transmissions and if there was a problem it would show up in their workshop. I'd be interested in getting some feedback from toddlamb on the number of miles on the transmissions they see and if they do see a lot with large mileage or track time. .

toddlamb

We have done several at 100k-150k miles and the main wear issue with those is the clutch material. Bearings showed no issues.

jjrichar

Thanks for the feedback. Much appreciated.

Do you see any with significant issues within the gear set? Sychromesh especially? I'm wondering with age if the gear actuation within the valve body starts to degrade that might cause some accelerated wear.

jjrichar

Looking for the help of an electronics expert to determine how to replace the electronics within the distance sensor. With my very limited electronics knowledge I'm thinking a linear hall sensor that has the correct sensitivity would fit the bill. Cost of these components from the research I've done seems to be very low, in the order of a few dollars.

The sensor gets a common 5V supply and ground with a single output voltage from each sensor that gives the position. I was using three AA batteries with a total output of 4.5V. Sensor response is about 4.2V with no magnet present, and about 0.4V with a strong magnet very close. The central position gives an output of about 2.5V.

Sensor construction is an aluminium shell that seems to have the electrical components installed and then filled with epoxy. I can't see that it would be too hard to grind out the old epoxy, install new electronics and then re-fill with epoxy.

Video below shows all of this and more. Any help would be appreciated.

You Tube

jjrichar

Anyone got a distance sensor that isn't working that they'd be willing to donate to the cause? I'm gathering parts to repair a distance sensor just to see if it can be done. I can make a test bed but to really see if it works I need a sensor I can repair then install to see if it works OK. Plan is to put all the information out there for everyone when done. More than happy to pay the postage to get it here down under. I'll send it back working if everything works out ok.

It looks like a cheap and relatively easy fix, with only a few components and very little electrical work.

Prairiedawg

That's awesome that you are putting the time and effort to get more information about these transmissions in the public square. I think that it's been commented on this thread elsewhere that there's nothing special about the distance sensors. They just require some electronics knowledge (that I don't have) to understand how they work and what's required to make better updated one's. I believe even @PV997 has complained that the new aftermarket one's out there are way overpriced for what they are and are taking taking advantage of the captive PDK market. I don't want to put words in his mouth but I think that was said. If that's the case then please, be part of the process to de-mystify these boxes. Everyone on this thread has done a ton of work to help do that but the distance sensors are still the mysterious electronic boxes. I have no problem with people/vendors profiting on their time, investment, and labors offering solutions where there was none. That's the free market. But if they're getting thousands of dollars for a part that costs just a couple hundred that is just using off the shelf technology, that makes them no better than Porsche offering only new boxes at that point. The guys tearing down the transmissions and putting the hours in are those who I sympathize with. There was a post above regarding the number of hours involved removal, tearing down, and replacing and programming. There's a real cost involved with that. I'm a mechanic by trade myself, but in another industry. I see first hand what's involved with major surgery in mechanical things and even when everything goes right, there's still hiccups and hours spent on the small stuff. A lot of it gets eaten by the shop.

I have no distance sensor to offer, only encouragement. I diagnose, troubleshoot, and repair things for a living. I have found it amazing that once you dive deeply in complex machines, you understand they are all man made and not nearly as sophisticated as they look. They're all made up of thousands of individual parts and mass produced, put together by other machines or hand. Once you understand even the most complicated and sophisticated things are all just simple but clever designs, it's much easier to have your "Aha" moment.

Hopefully someone will be king enough to send a sensor your way. Great video's by the way.


.

jjrichar

Thanks for the positive words. Much appreciated.

If anyone is interested there is a thread running on Planet 9 in the 981 Chat section titled 'Seeking the help of an electronics expert'. I'm in discussion a pretty knowledgeable person on how we are working out what parts etc are required.. Honestly it looks like there is about $10 of parts in there. I am a little amazed how inexpensive a hall sensor is, especially considering how complex it is inside. If you were making the sensor case as well I think this is where the majority of the cost would be. Hence why I personally think a good option is to keep the existing casing and just replace the components.

I'm more than happy with what T design have done with their pricing. They did the work to find an alternative, and have priced where they are comfortable. The problem is when someone comes along and thinks it's a bit pricey and they can do it cheaper. It's capitalism at it's best. The more people in a market the better, and I guess that's what I'm trying to create.

Floyd540

This is not useful and I am a ME (mechanical engineer) and not a degreed or licensed EE, but we still have the ability to say stuff. Back in the day we designed in LVDT's for no contact precise position measurements in hostile hard to get at conditions. Highly accurate, realible, cheap, long life (200 million cycles common) and any electronics can be mounted externally. Hall effect units work well , cheap and reliable but with on board electronics that will go bad. Useful devices as long as they can be serviced easily like in cam position and flywheel sensors. One bolt and you replace it. PDK position sensing is a simple task but servicing them is impossible. Seems dumb to me.

docdrs

iirc. Someone on here already diy’d a sensor replacing the internals and repotting it. Can’t remember if it worked, but it was shortly after that that the aftermarket ones became available. I think he was the developer and then he or someone ran with the idea to make some $$$$. However , the testing , the warranty of this product has to be considered. The labour is the factor, unless it’s diy, if the sensor is defective or something….. and everyone likes to point fingers…..I constantly think about what I will do when mine goes as I plan on keeping the car for a long time. But then I also look at the HPFP and wonder if We should start a buy group to source these out as they seem to be a consumable ?

PV997

@jjrichar - Apologies, just saw this. We've corresponded in the past and your stuff at Planet 9 is top-notch (particularly your PIWIS stuff), I like how you think and it's good to see you posting over here. If you still have my email please drop me a note or send me a PM and I'll send you my email address. I finally cleaned out my inbox after being full for a six months.

I have a sensor and would welcome the opportunity to work with like-minded people to develop a low cost, not-for-profit alternative sensor. This would be done as a community project and people would use the sensor at their own risk. I considered doing this about a year ago but became tied up with my day job and family stuff and have not had the opportunity. I need help with the housing (machined, cast, or AM), PWB layout, and the potting. I understand the circuit and programming, that's the easy part. Turning it into a useable, reliable assembly is where help is needed.

If people have a background in any of these areas and are like-minded, please send me a PM. This is not a business solicitation but a non-profit, crowd-sourced opportunity to help the Rennlist community.

jjrichar

More information on the distance sensor for those who are interested.

Big thanks to PV997 for his help over the last few days. There is clearly a massive brain on his shoulders and his knowledge is going to be key in making the project a reality.