Hi Jeff, We installed wavetrac diff and changed the driveshaft becz of the damage happened in a drag race. After the installation (2x times), drive the car for 20 mins and pdk go crazy and throw the codes (transmission fluid pressure circuit A and B) Also, we noticed that clutch oil got/moved to the tans oil and mixed..!! The tech suspected the seal on the shaft caused the leak, and replaced it, still getting the same issue after 20 mins of driving. One more thing to mention, factory diff is operating by oil while the aftermarket wavetrac LSD is purely mechanical so we had to clog the oil input hole in the differential cover as instructed by the supplier. (I suspect that clogging this hole is mostly related to the following codes). However, how do we cancel oem diff oil line properly to convert to mechanical LSD??? The logs are throwing codes (p0841) Transmission Fluid Pressure Sensor Circuit A and (p0846) same but Circuit B. BTW, the car is 991 Turbo S 2014
This is beyond my level of knowledge/experience, but I'll pass some information that might help. If there is halfshaft or diff work done, one of the major risks is the double seal on the long halfshaft being displaced and so you get a lot of oil movement between chambers. This is the advice I've been given by a shop who specialises in track cars. This is occurs regularly from crashes. He has told me this then causes valve body damage. Why? I don't really know, but he fixes a lot of PDK track cars where a tech has incorrectly installed the seal, there has been consequent fluid transfer between chambers, and the VB is damaged. So is this your cause? I have no idea, but it might be worth investigating. Is the hole you are talking about the large one below the pinion gear? If so, I don't know why they say to block that as the diff will run dry. Below is an extract from the Porsche docs that explains all the PDK codes. This is for the P0841 but it's the same for the P0846, just the other clutch channel. It's basically saying there is a pressure deviation from what is expected at the different temperatures. I suspect this is occurring as things warm. A question. Are both codes occurring at exactly the same time, or is it happening kind of at the same time. If occurring at exactly the same time it might be a common electrical problem, either with the 5V supply or the ground that is common to both to both pressure sensors. P0841 Diagnosis information PDK control unit Pressure sensor 1 measured value implausible Diagnostic conditions I Driving in all gears Possible fault causes J Hydraulics faulty J Transmission faulty J Pressure sensor 1 faulty Fault setting condition(s) I Pressure deviation of clutch 1 adapted > threshold (temperaturedependent characteristic) 30 10 0 10 45 90 °C (22 14 32 50 113 194 °F) 1.75 1.55 1.45 1.35 1.25 1.25 bar I Pressure deviation of clutch 1 not adapted > threshold (temperaturedependent characteristic) 30 10 0 10 45 90 °C (22 14 32 50 113 194 °F) 2.25 2.05 1.75 1.5 1.5 1.5 bar Fault effects J Transmission limphome display in the instrument cluster control unit J Driving with gear train half 2 (only 2nd, 4th and 6th gears) J No R gear J No start/stop J Torque limitation J No emergency program diagnostics J All adaptations are deactivated J Clutchoverlap function is deactivated, i.e. one clutch is not closed until the other clutch is opened during the gearchanging process.
@@jeffrichardsoncardiy We have changed the drive shaft along with the diff. The holes got clogged are the two in the factory diff cover because the aftermarket LSD is purely mechanical so no need for the oil. Regarding the error/codes, both are coming together at the same time and the cluster shows a message Gearbox failure, No R gear. The car goes into limp mode and engine check light comes on. Do you think clogging those two holes could cause the oil to move from place to another and mix?
I also have have play in front right diferential flange on my panamera...maybe 3/8 of inch up/down or left/right. Is that normal? I m also getting noise like bad wheel bearing on that side.
The axle flange joint on the differential side on my pdk seems to be loose and have play. That’s not normal right? I have no leaks and the transmission acts fine but I hear noises at low speed as if the axle was going bad. Is it possible to just tighten it?
It should have a small amount of movement both in/out as well sideways. The spline isn't an interference fit and is just held there by the circlip. If there is excessive movement it might be the differential bearings. This would require much more force to make it wobble as the differential is quite heavy. If you are just holding onto the flange and it's moving a bit easily by hand that's perfectly normal. There's no way to tighten it. Very hard to diagnose a noise without being there, as there are loads of different moving parts in that area. I'm not sure how many miles the car has but I'd definitely recommend fluid changes as the first thing to do.
No idea. I didn't remove and measure. They might be something that can be bought off the shelf from a bearing supplier. Regarding the main shaft bearings, these came from a bearing supplier.
Excellent series. To replace a factory LSD diff with an aftermarket Guard LSD the instructions from the supplier are "the original differential bearing must be carefully removed from the stock limited slip and reused on the new limited slip unless you have a Clubsport, which in that case new differential bearings can be purchased from PMNA." Not sure why only the Clubsport has replaceable diff bearings. Do you think getting them off without damaging would be straight forward and is there likely to be an aftermarket source to replace the diff bearings?
Honestly I don't have the experience or expertise to answer these questions. I expect that the bearings on a clubsport are such that removal can't be done with a standard bearing removal tool, which is why they say to replace. You would have to remove the diff and inspect to see how easy it is to remove. I don't have one of these diffs to give you any guidance. Aftermarket bearings? Again you would have to get the diff in your hands and take a look at the part numbers and then search. You would expect the bearings to be off the shelf, but as I've discovered, many of these items are bespoke for the transmission.
Really helpful thanks. I need to remove the long shaft ("flange", as they call it). Manual seems to suggest I need to remove short shaft and diff to get long shaft out. Is that necessary? I just need to replace long shaft seal.
No. It should just pop straight out like in the video. It's in there surprisingly lightly. You don't really need a slide hammer. A long M10 bolt and piece of steel over it would probably be enough.
