PDK / Gear oil

[Boxsters]

Hello,

Has anyone changed Gear oil on PDK gearbox ? DIY ?

[JFP in PA]

Depends, as you will need the PIWIS. The PDK requires two different lubricants, one for the wet clutches, the other for the gearbox itself. Both should be changed. As very limited information is available for the PDK, the OEM lubes whould be the best choice.

From the manual:

PDK transmission oil - approx. 3.12 quarts / 2.95 liters ATF transmission oil Mobilube PTX Formula A (SAE 75W-90) GL 4.5 - change at 120K miles or 12 yearsPDK clutch oil - approx. 5.49 quarts / 5.2 liters Pentosin Gear Oil FFL 3 - change at 60 K miles or 6 yearsThe following procedure is from the 2009 Technik Service information book:Oil fillingThe correct hydraulic oil level is important for operating the transmission withoutrunning into problems. The following preconditions must be met in order to check orcorrect the oil level:• Engine must be idling• Vehicle must be horizontal in both longitudinal and transverse axis• Hydraulic oil temperature between 86° F. and 104° F. (30° C and 40° C)• Selector-lever position “P”• Clutch cooling volume flow must be switched off (using PIWIS Tester in Oil fillmode)• Retain the described states for approx. 1 minute to allow the oil to settle• Open screw plug on oil overflow bore and collect emerging oil until only drops ofoil are emerging• Once there is no more oil emerging, top up the clutch fluid until oil emerges atthe oil overflow bore• To avoid damaging the clutches, the procedure must be completed within 5 minutes(PIWIS Tester exits Oil fill mode automatically after 5 minutes)The correct oil level is also important to avoid damaging the gear wheels in thetransmission. There is also an overflow bore for this, which is located on the oppositeside. The oil level can be checked in the usual way here.

[Boxsters]

Thanks JFP,

I have a 997 S / PDK and think it to long for first oil change with 12 years / 120 K miles.

I have seen that procedure in the 2009 Technik Service information book,

Is PIWIS needed for the (PTX) gear oil change also, Shouldn´t that be more or less a drain and

refill procedure ? I can have it done att dealer but qurios if it would be possible to change out just the

gearoil easily.

[JFP in PA]

Thanks JFP,

I have a 997 S / PDK and think it to long for first oil change with 12 years / 120 K miles.

I have seen that procedure in the 2009 Technik Service information book,

Is PIWIS needed for the (PTX) gear oil change also, Shouldn´t that be more or less a drain and

refill procedure ? I can have it done att dealer but qurios if it would be possible to change out just the

gearoil easily.

I would tend to agree that 12years/120K miles is a long way to go on any lubricant, particular one that is keeping a $17K gear box alive.

Porsche is using the PIWIS to control how the lubricants are moving inside the gear box while setting the correct fluid level, and in particular the clutch hydraulic fluid. I would be concerned that skipping that step could lead to either an over or under fill condition, either of which can lead to problems. The PTX gear oil is a conventional overflow type fill like those found on regular manual gearboxes. You should also note that both lubricants where initially difficult to find over here, and were only available from a dealer.

As the current dealer standard procedure for dealing with a PDK that is acting up is to put a new one in the car, which is fine while under warranty, you really don't want to find yourself having to buy one. Like most sequential manual gearboxes on the market, there is no field service for these units, hurt one and they have to go back to the factory.

[Boxsters]

Thanks JFP,

Ok,i was not aware that both of the fluids needed to be controlled to get the correct fluid levels inside the box.

It doesent sound to me that is a risk i am willing to take and mess upp things...which will end

up costing me $$$.

[JFP in PA]

As you have to change the clutch fluid (which must use the PIWIS) twice for every time the gear oil is changed once, the dealer (or indy with a PIWIS) would be the safer bet.

[stronbl]

Slight variation on the above request (great info and feedback by the way) ... is it possible to simply "inspect" the PDK for proper levels and top off as necessary (I don't believe I need gear oil change service)? I suppose a good tech (indy or dealer) could handle it. But I track my car and want to ensure the PDK is ready and willing before the up coming track season and would like to DIY if possible. Any comments?

Thanks.

PS - the car is a 2010 997.2 C4S

[JFP in PA]

As I mentioned is postings # 2 & 4 above, it is my understanding that the system has to be active and connected to the PIWIS to set the correct fluid levels for the clutch, while the gearbox is a simpler overflow system like a manual gearbox. At this time, I am not aware of an aftermarket alternative to the PIWIS, such as Durametric, being able to do this step. So the indy would need to have a PIWIS.

With enough of these systems on the street, I am sure someone will develop a "work around" to get it done, or that the aftermarket will develop diagnostic tools to help, but right now I know of none that will do the job.

[paul29]

"Clutch cooling volume flow must be switched off" may I assume this means a fluid coolant circulating pump/circuit is temporarily disabled, now is there an electrical connection to this pump or solenoid valve that can be opened/energised to achieve the same condition as using the PIWIS?

[JFP in PA]

"Clutch cooling volume flow must be switched off" may I assume this means a fluid coolant circulating pump/circuit is temporarily disabled, now is there an electrical connection to this pump or solenoid valve that can be opened/energised to achieve the same condition as using the PIWIS?

The clutch lubricant is circulated to a oil/water cooler on the side of the gearbox, the controls are internal to the PDK control computer. The clutch oil pump is inside the bell housing, not unlike an traditional automatic transmission:Changing the clutch oil flow requires activating a valve inside that pump, hence the use of the PIWIS to control it.

[2003996C2]

Depends, as you will need the PIWIS. The PDK requires two different lubricants, one for the wet clutches, the other for the gearbox itself. Both should be changed. As very limited information is available for the PDK, the OEM lubes whould be the best choice.

JFP,Would it be unusual to see some small slivers of metal when the gear oil is drained for the first time? Mine was drained today at 53k miles and my reputable indy said there were some but it was minimal and I shouldn't be concerned. I've read that is not unusual to see some debris left over from the manufacturing process in the oil pan when it is pulled for the first. Has that been your experience and do think it would apply on a PDK? Thank you.

[JFP in PA]

Like just about any new gear box, or engine for that matter, there will always be some build/break in debris in the first lube change, which is why many make the first change early just to clean it out. I would not be at all concerned unless the quantity or debris pieces themselves are plentiful or particularly gritty.

[2003996C2]

Thanks for the input!

[slicky rick]

it seems with the pdk tech coming to 5 years no one has really gone into changing the clutch oils and the gear oils of the pdk. why is this? is it fear of something new? has anyone documented a real clutch oil change and gearbox oil change?

in addition, i am a bit confused, my 10C2S has limited slip diff. is there a separate gear oil for this or is the oil for this part automatically renewed when gearbox oil is changed? i hope jfp is still in town and can enlighthen us on the subject.

[JFP in PA]

it seems with the pdk tech coming to 5 years no one has really gone into changing the clutch oils and the gear oils of the pdk. why is this? is it fear of something new? has anyone documented a real clutch oil change and gearbox oil change?

in addition, i am a bit confused, my 10C2S has limited slip diff. is there a separate gear oil for this or is the oil for this part automatically renewed when gearbox oil is changed? i hope jfp is still in town and can enlighthen us on the subject.

Yes, the differential in inside the gearbox (see the cutaway photos in my post #10 above). Except for the gear selection controls, the gearbox is very similar to the manual seven speed gearbox, but the larger issue is changing the clutch oil (which is different) and requires the use of a PIWIS system to accomplish.

[Mijostyn]

"Clutch cooling volume flow must be switched off" may I assume this means a fluid coolant circulating pump/circuit is temporarily disabled, now is there an electrical connection to this pump or solenoid valve that can be opened/energised to achieve the same condition as using the PIWIS?

The clutch lubricant is circulated to a oil/water cooler on the side of the gearbox, the controls are internal to the PDK control computer. The clutch oil pump is inside the bell housing, not unlike an traditional automatic transmission: Porsche manual vs PDK cutaway.jpg Changing the clutch oil flow requires activating a valve inside that pump, hence the use of the PIWIS to control it.

Nice picture JFP. Where are the solenoids that operate the gear box and clutches?? I hope they are easy to get to as they are the most likely parts to fail. It is cool that the gear boxes are almost identicle! I wonder how it gets itself into first gear in sub zero temps? The first shift at -10 degrees is like rowing through molasses. Does it go to bed in first gear?

[JFP in PA]

"Clutch cooling volume flow must be switched off" may I assume this means a fluid coolant circulating pump/circuit is temporarily disabled, now is there an electrical connection to this pump or solenoid valve that can be opened/energised to achieve the same condition as using the PIWIS?

The clutch lubricant is circulated to a oil/water cooler on the side of the gearbox, the controls are internal to the PDK control computer. The clutch oil pump is inside the bell housing, not unlike an traditional automatic transmission: Porsche manual vs PDK cutaway.jpg Changing the clutch oil flow requires activating a valve inside that pump, hence the use of the PIWIS to control it.

Nice picture JFP. Where are the solenoids that operate the gear box and clutches?? I hope they are easy to get to as they are the most likely parts to fail. It is cool that the gear boxes are almost identicle! I wonder how it gets itself into first gear in sub zero temps? The first shift at -10 degrees is like rowing through molasses. Does it go to bed in first gear?

A lot of the control system is internal to the gearbox and operated remotely by the computer, which is why a lot of independent's are kind of stuck on servicing the transmission (at this time, there is not an aftermarket system such as the Durametric that can even do the clutch oil change out, which happens with twice the frequency of the gearbox lube itself, due to the necessity of a PIWIS system). The transmission is decidedly not technician friendly, and the dealers are not going much beyond changing both oils and re-flashing the computer before swapping out the unit for a replacement when problems occur.

Because the trans is basically an "automated" version of the manual 7 speed, I think the trans stays in whatever gear it was shut off in (probably to facilitate the new auto start/stop function), but there is no real way of telling as it seems to go through a series of diagnostic checks as the car starts.

Here's one out of the car, and there really is not much to see:

[Mijostyn]

"Clutch cooling volume flow must be switched off" may I assume this means a fluid coolant circulating pump/circuit is temporarily disabled, now is there an electrical connection to this pump or solenoid valve that can be opened/energised to achieve the same condition as using the PIWIS?

The clutch lubricant is circulated to a oil/water cooler on the side of the gearbox, the controls are internal to the PDK control computer. The clutch oil pump is inside the bell housing, not unlike an traditional automatic transmission: Porsche manual vs PDK cutaway.jpg Changing the clutch oil flow requires activating a valve inside that pump, hence the use of the PIWIS to control it.

Nice picture JFP. Where are the solenoids that operate the gear box and clutches?? I hope they are easy to get to as they are the most likely parts to fail. It is cool that the gear boxes are almost identicle! I wonder how it gets itself into first gear in sub zero temps? The first shift at -10 degrees is like rowing through molasses. Does it go to bed in first gear?

A lot of the control system is internal to the gearbox and operated remotely by the computer, which is why a lot of independent's are kind of stuck on servicing the transmission (at this time, there is not an aftermarket system such as the Durametric that can even do the clutch oil change out, which happens with twice the frequency of the gearbox lube itself, due to the necessity of a PIWIS system). The transmission is decidedly not technician friendly, and the dealers are not going much beyond changing both oils and re-flashing the computer before swapping out the unit for a replacement when problems occur.

Because the trans is basically an "automated" version of the manual 7 speed, I think the trans stays in whatever gear it was shut off in (probably to facilitate the new auto start/stop function), but there is no real way of telling as it seems to go through a series of diagnostic checks as the car starts.

Here's one out of the car, and there really is not much to see:

What is that Blue knob at the top rear on the driver's side? What is that black knob down low a bit to the front with the diagonal grooves with the sheet metal bracket under it??

In general how are these boxes holding up? I'm hoping that they have most of the bugs worked out by now. Any weaknesses I should know about? I assume when you send these back they send you a rebuild and give you a core charge? How much??

[JFP in PA]

"Clutch cooling volume flow must be switched off" may I assume this means a fluid coolant circulating pump/circuit is temporarily disabled, now is there an electrical connection to this pump or solenoid valve that can be opened/energised to achieve the same condition as using the PIWIS?

The clutch lubricant is circulated to a oil/water cooler on the side of the gearbox, the controls are internal to the PDK control computer. The clutch oil pump is inside the bell housing, not unlike an traditional automatic transmission: Porsche manual vs PDK cutaway.jpg Changing the clutch oil flow requires activating a valve inside that pump, hence the use of the PIWIS to control it.

Nice picture JFP. Where are the solenoids that operate the gear box and clutches?? I hope they are easy to get to as they are the most likely parts to fail. It is cool that the gear boxes are almost identicle! I wonder how it gets itself into first gear in sub zero temps? The first shift at -10 degrees is like rowing through molasses. Does it go to bed in first gear?

A lot of the control system is internal to the gearbox and operated remotely by the computer, which is why a lot of independent's are kind of stuck on servicing the transmission (at this time, there is not an aftermarket system such as the Durametric that can even do the clutch oil change out, which happens with twice the frequency of the gearbox lube itself, due to the necessity of a PIWIS system). The transmission is decidedly not technician friendly, and the dealers are not going much beyond changing both oils and re-flashing the computer before swapping out the unit for a replacement when problems occur.

Because the trans is basically an "automated" version of the manual 7 speed, I think the trans stays in whatever gear it was shut off in (probably to facilitate the new auto start/stop function), but there is no real way of telling as it seems to go through a series of diagnostic checks as the car starts.

Here's one out of the car, and there really is not much to see:

What is that Blue knob at the top rear on the driver's side? What is that black knob down low a bit to the front with the diagonal grooves with the sheet metal bracket under it??

In general how are these boxes holding up? I'm hoping that they have most of the bugs worked out by now. Any weaknesses I should know about? I assume when you send these back they send you a rebuild and give you a core charge? How much??

I believe it is the clutch oil fill.

Some of the early cars had software issues that caused surging complaints, but they have updated the system. Because these are an offshoot of Porsche Motorsports, these things should be very strong.

It's hard to get the dealers to give you straight numbers, but what I have heard is that the twin clutch unit (parts only) is $5-6K, and a replacement transmission, sitting on the ground in a crate, is about $15-17K. I have not heard any core swap numbers.

As you originally asked about the control system, thought you might enjoy this video of Jay Leno taking one apart and then beating Hell out of a car with one. Be sure to note what looks like an over sized valve body on the table by the opened up trans; that is your control system: http://www.youtube.com/watch?v=R0t2xia8xxs&feature=player_embedded

[Mijostyn]

Interesting video. Thanx JFP. I wish he would learn to pronounce Porscheeee correctly. He does it just to irritate us!

[JFP in PA]

Interesting video. Thanx JFP. I wish he would learn to pronounce Porscheeee correctly. He does it just to irritate us!

When you've got that much money, you can be as irritating as you like.............. :eek:

[Boxsters]

I got my PDK gearbox oil changed a couple of Days ago at my OPC dealer.

no Pictures though but looked very straight forward when i looked underneath my car.

Mobil PTX 75W/90 Oil  (also factory fill)

[JFP in PA]

I got my PDK gearbox oil changed a couple of Days ago at my OPC dealer.

no Pictures though but looked very straight forward when i looked underneath my car.

Mobil PTX 75W/90 Oil  (also factory fill)

 

The gear box oil change on the PDK is the same as any manual gear box; drain and refill until it seeps out the overflow.  The trick on the PDK is the clutch oil, which requires the use of a PIWIS to accomplish.

[Boxsters]

Yes it looks like it, only need to remove the first plastic underbody panel.

The drain and fill plugs did not have crush washers but a small rubber seal instead.

[slicky rick]

Boxsters, you watched them do it. How long did the whole procedure of changing both oils take, clutch oil and gear oil? Did you notice any difference in performance after the service?