Suspension Lock and Gearbox Oil Change - CONFLICTING INFO???
07-23-2018, 10:33 AM
#1
Suspension Lock and Gearbox Oil Change - CONFLICTING INFO???
Hi guys!
Currently have my 955 Cayenne Turbo on my two post lift undertaking some work with a leaking ATF pipe that attaches to the top radiator.
The suspension was locked before lifting the car, and when I replace the ATF pipe I will need to top up the ATF fluid. Looked into this process, being level, fine, topping up whilst getting second person to shift P>D>R back and forth to distribute fluid, fine, keep topping up until fluid is 40 degrees Celsius, all fine.
With one exception...
To get it up to 40 degrees the engine will of course need to be running, which means the second person changing the gears will be making the wheels turn when in D and R gears (or do you keep your foot on the brake and not let the wheels move?)
I noted that the air suspension lock with automatically switch off when you drive off. So will selecting the gears make the car think it's driving and switch off the suspension lock whilst on the ramp?
Or, does the second person hold the brake down whilst shifting the gears so that the wheels don't turn, and so the lock won't switch off accidentally?
Any help much appreciated!! :-)
Currently have my 955 Cayenne Turbo on my two post lift undertaking some work with a leaking ATF pipe that attaches to the top radiator.
The suspension was locked before lifting the car, and when I replace the ATF pipe I will need to top up the ATF fluid. Looked into this process, being level, fine, topping up whilst getting second person to shift P>D>R back and forth to distribute fluid, fine, keep topping up until fluid is 40 degrees Celsius, all fine.
With one exception...
To get it up to 40 degrees the engine will of course need to be running, which means the second person changing the gears will be making the wheels turn when in D and R gears (or do you keep your foot on the brake and not let the wheels move?)
I noted that the air suspension lock with automatically switch off when you drive off. So will selecting the gears make the car think it's driving and switch off the suspension lock whilst on the ramp?
Or, does the second person hold the brake down whilst shifting the gears so that the wheels don't turn, and so the lock won't switch off accidentally?
Any help much appreciated!! :-)
07-23-2018, 11:24 PM
#2
Do not let the wheels spin. Suspension regulation is irrelevant. By the book, if you open the cooler circuit, then you need to get the trans to 90c so that the the thermostat will open and purge the cooler/lines of any air. (90c is not the cracking temp of the thermostat but the fully open temp. Cracking is around 74c.) Let the trans cool to 40c and then do the fill procedure.
Sounds like you are committed to working on the Cayenne. The best advice I can give you is to get yourself a factory service manual. There are threads here that talk about where to get them but they are not hard to find.
Sounds like you are committed to working on the Cayenne. The best advice I can give you is to get yourself a factory service manual. There are threads here that talk about where to get them but they are not hard to find.
07-24-2018, 06:05 AM
#3
Thank you for the reply - much appreciated :-)
Yes, I got the instructions from two sources actually:
https://www.pelicanparts.com/techart...ter_Change.htm
and also on this forum:
https://rennlist.com/forums/cayenne-...il-change.html
They only mention the 40 degree's (c), but I guess like you mentioned as a pipe is being replaced that attaches to the cooler then that will contain air and so that needs to be purged. Will the gearbox get to 90 degree's c just idling??? What's the approx maximum working temp of the gearbox?
---
BTW, I have a workshop manual which is in PDF form actually. When I open it in a web browser it does not load the entire thing as hundreds of pages. I'm going to download acrobat reader and see if that will load the full doc in one so I can do a text search to try and find what I need as there is no kind of navigation or menu system.
Yes, I got the instructions from two sources actually:
https://www.pelicanparts.com/techart...ter_Change.htm
and also on this forum:
https://rennlist.com/forums/cayenne-...il-change.html
They only mention the 40 degree's (c), but I guess like you mentioned as a pipe is being replaced that attaches to the cooler then that will contain air and so that needs to be purged. Will the gearbox get to 90 degree's c just idling??? What's the approx maximum working temp of the gearbox?
---
BTW, I have a workshop manual which is in PDF form actually. When I open it in a web browser it does not load the entire thing as hundreds of pages. I'm going to download acrobat reader and see if that will load the full doc in one so I can do a text search to try and find what I need as there is no kind of navigation or menu system.
07-24-2018, 12:16 PM
#4
RL Community Team
Rennlist Member
Rennlist Member
Why not fill it as far as you can on the lift, then set it down on the ground, put it into a taller mode like terrain mode or special terrain mode where you can be under it topping up while someone is inside doing the shifting while holding the brakes with the parking brake also on? If you can't get it high enough that way, you should be able to get it high enough where you could drive up onto 4 Rhino Ramps either forward or backward, which would still keep it level and give you another 8" or so. Having 2 pairs of light and strong ramps can come in handy from time to time.
07-24-2018, 01:17 PM
#5
Hi there! That's for the reply, but I can't see how that would benefit over a two post lift 
The height is not an issue, and having looked at the workshop manual (works better in Acrobat Reader!!) J'sWorld is spot on. Needs to be allowed to get up to 90 degree's for the cooling circuit to switch on and pump it around the oil cooler etc.
Just amazed it gets to 90 just idling. Driving, yes, as I would assume 90 degree's is about it's normal working tempurature, just hoping it will get there ok just idling.
I've replaced the leaking pipe. I may have to do the standard 40 degree top up procedure to ensure there is enough fluid in there, then after that run it up to 90 to get the cooler circuit to open, then let is all cool down and repeat the 40 segree procedure to get the final level spot-on. That's the plan anyway
The height is not an issue, and having looked at the workshop manual (works better in Acrobat Reader!!) J'sWorld is spot on. Needs to be allowed to get up to 90 degree's for the cooling circuit to switch on and pump it around the oil cooler etc.
Just amazed it gets to 90 just idling. Driving, yes, as I would assume 90 degree's is about it's normal working tempurature, just hoping it will get there ok just idling.
I've replaced the leaking pipe. I may have to do the standard 40 degree top up procedure to ensure there is enough fluid in there, then after that run it up to 90 to get the cooler circuit to open, then let is all cool down and repeat the 40 segree procedure to get the final level spot-on. That's the plan anyway
07-24-2018, 02:05 PM
#6
RL Community Team
Rennlist Member
Rennlist Member
Hi there! That's for the reply, but I can't see how that would benefit over a two post lift
The height is not an issue, and having looked at the workshop manual (works better in Acrobat Reader!!) J'sWorld is spot on. Needs to be allowed to get up to 90 degree's for the cooling circuit to switch on and pump it around the oil cooler etc.
Just amazed it gets to 90 just idling. Driving, yes, as I would assume 90 degree's is about it's normal working tempurature, just hoping it will get there ok just idling.
I've replaced the leaking pipe. I may have to do the standard 40 degree top up procedure to ensure there is enough fluid in there, then after that run it up to 90 to get the cooler circuit to open, then let is all cool down and repeat the 40 segree procedure to get the final level spot-on. That's the plan anyway
The height is not an issue, and having looked at the workshop manual (works better in Acrobat Reader!!) J'sWorld is spot on. Needs to be allowed to get up to 90 degree's for the cooling circuit to switch on and pump it around the oil cooler etc.
Just amazed it gets to 90 just idling. Driving, yes, as I would assume 90 degree's is about it's normal working tempurature, just hoping it will get there ok just idling.
I've replaced the leaking pipe. I may have to do the standard 40 degree top up procedure to ensure there is enough fluid in there, then after that run it up to 90 to get the cooler circuit to open, then let is all cool down and repeat the 40 segree procedure to get the final level spot-on. That's the plan anyway
07-24-2018, 02:33 PM
#7
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07-24-2018, 03:27 PM
#8
Instructor
Hold your foot on the brake when you're shifting the gears. It takes a few seconds of rolling for the service mode to come off. I just did this myself this weekend, no problems.
07-24-2018, 03:57 PM
#9
Did you do the standard 40 degree's ATF fluid change/top up, or did you have to do the full 90 degree pipe replacement top up like I'll be having to do?
07-24-2018, 04:21 PM
#10
Instructor
I did a pan drop and oil/filter change, which you might consider doing so you're only in there once.
This process is exactly the same for most modern German cars (Merc, BMW, etc.). You want the transmission and fluid cold. Fill through the fill port until fluid comes out.
Turn the car on, run the trans through the gears (just the shifter is fine) while holding foot on the brake. Leave the car in Park and running and run the lift back up, then watch your trans temp (you can use SW or just use an infra-red thermometer on the pan). When the trans temp reaches 40c (about 104f) then finish the fill until fluid comes out. Quickly replace the fill plug and you're done.
This is not a race against time - it can be +/- 40c when you do this just get it in the ballpark. You want the fluid WARM - not overly hot (unlikely to happen with the car in just idling) but also not cold as it will be overfilled.
I actually suspect that the manufacturers use 40c more for safety than anything else so you don't have scalding fluid coming out.
This process is exactly the same for most modern German cars (Merc, BMW, etc.). You want the transmission and fluid cold. Fill through the fill port until fluid comes out.
Turn the car on, run the trans through the gears (just the shifter is fine) while holding foot on the brake. Leave the car in Park and running and run the lift back up, then watch your trans temp (you can use SW or just use an infra-red thermometer on the pan). When the trans temp reaches 40c (about 104f) then finish the fill until fluid comes out. Quickly replace the fill plug and you're done.
This is not a race against time - it can be +/- 40c when you do this just get it in the ballpark. You want the fluid WARM - not overly hot (unlikely to happen with the car in just idling) but also not cold as it will be overfilled.
I actually suspect that the manufacturers use 40c more for safety than anything else so you don't have scalding fluid coming out.
07-24-2018, 06:27 PM
#11
Hi there! That's for the reply, but I can't see how that would benefit over a two post lift
The height is not an issue, and having looked at the workshop manual (works better in Acrobat Reader!!) J'sWorld is spot on. Needs to be allowed to get up to 90 degree's for the cooling circuit to switch on and pump it around the oil cooler etc.
Just amazed it gets to 90 just idling. Driving, yes, as I would assume 90 degree's is about it's normal working tempurature, just hoping it will get there ok just idling.
I've replaced the leaking pipe. I may have to do the standard 40 degree top up procedure to ensure there is enough fluid in there, then after that run it up to 90 to get the cooler circuit to open, then let is all cool down and repeat the 40 segree procedure to get the final level spot-on. That's the plan anyway
The height is not an issue, and having looked at the workshop manual (works better in Acrobat Reader!!) J'sWorld is spot on. Needs to be allowed to get up to 90 degree's for the cooling circuit to switch on and pump it around the oil cooler etc.
Just amazed it gets to 90 just idling. Driving, yes, as I would assume 90 degree's is about it's normal working tempurature, just hoping it will get there ok just idling.
I've replaced the leaking pipe. I may have to do the standard 40 degree top up procedure to ensure there is enough fluid in there, then after that run it up to 90 to get the cooler circuit to open, then let is all cool down and repeat the 40 segree procedure to get the final level spot-on. That's the plan anyway
90c is fully open, 74c is cracking, I only know this because I tested it when deciding if I was going to keep it or not. My Cayenne does not use that trans cooler anymore as I now have a different one mounted in a different spot with its own dedicated fan and controller. It may be more work but your doing it right.
Starting at 150°C (270°F), the converter clutch is applied more frequently. If this does not result in cooling of the ATF, reduction of engine torque is initiated at 170°C (306°F). Should the TFT(temp sensor) fail, a substitute value is generated from the engine temperature and operating duration.There will be no controlled operation (ramping) of the converter clutch (ON or Off only) and no controlled shift adapt pressures, which usually results in harsh engagements.
07-25-2018, 12:50 PM
#12
Hi guys!
Just a quick update on this. Did it today. No drama's - all fairly straight forward really. It took over two litres to top it back up so lost a fair bit due to that leak. Thankfully it's been stood and not driven during most of that time.
However, as I half expected, the gearbox will not get to 90 degree's just idling. I had it idling for the best part of an hour and the highest it got was just touching 70 degree's C.
So to get it up to full temp I think it has to be driven. That's where diagnostic software like Durametrics comes inhandy (which I don't have) so you can see that the temp has definitely hit 90 out on a drive before returning back. Impossible using my little handheld infared temp gun, lol!!!
So I think basically give it a good run to get to 90 degrees and make the cooling circuit open up, then cool it all back down (overnight most likely) and repeat the normal 40 degree fill procedure if replacing a pipe like I had to.
But definitely was not going to hit 90 degree's idling. Unfortunately
Just a quick update on this. Did it today. No drama's - all fairly straight forward really. It took over two litres to top it back up so lost a fair bit due to that leak. Thankfully it's been stood and not driven during most of that time.
However, as I half expected, the gearbox will not get to 90 degree's just idling. I had it idling for the best part of an hour and the highest it got was just touching 70 degree's C.
So to get it up to full temp I think it has to be driven. That's where diagnostic software like Durametrics comes inhandy (which I don't have) so you can see that the temp has definitely hit 90 out on a drive before returning back. Impossible using my little handheld infared temp gun, lol!!!
So I think basically give it a good run to get to 90 degrees and make the cooling circuit open up, then cool it all back down (overnight most likely) and repeat the normal 40 degree fill procedure if replacing a pipe like I had to.
But definitely was not going to hit 90 degree's idling. Unfortunately
07-25-2018, 05:45 PM
#13
Hi guys!
Just a quick update on this. Did it today. No drama's - all fairly straight forward really. It took over two litres to top it back up so lost a fair bit due to that leak. Thankfully it's been stood and not driven during most of that time.
However, as I half expected, the gearbox will not get to 90 degree's just idling. I had it idling for the best part of an hour and the highest it got was just touching 70 degree's C.
So to get it up to full temp I think it has to be driven. That's where diagnostic software like Durametrics comes inhandy (which I don't have) so you can see that the temp has definitely hit 90 out on a drive before returning back. Impossible using my little handheld infared temp gun, lol!!!
So I think basically give it a good run to get to 90 degrees and make the cooling circuit open up, then cool it all back down (overnight most likely) and repeat the normal 40 degree fill procedure if replacing a pipe like I had to.
But definitely was not going to hit 90 degree's idling. Unfortunately
Just a quick update on this. Did it today. No drama's - all fairly straight forward really. It took over two litres to top it back up so lost a fair bit due to that leak. Thankfully it's been stood and not driven during most of that time.
However, as I half expected, the gearbox will not get to 90 degree's just idling. I had it idling for the best part of an hour and the highest it got was just touching 70 degree's C.
So to get it up to full temp I think it has to be driven. That's where diagnostic software like Durametrics comes inhandy (which I don't have) so you can see that the temp has definitely hit 90 out on a drive before returning back. Impossible using my little handheld infared temp gun, lol!!!
So I think basically give it a good run to get to 90 degrees and make the cooling circuit open up, then cool it all back down (overnight most likely) and repeat the normal 40 degree fill procedure if replacing a pipe like I had to.
But definitely was not going to hit 90 degree's idling. Unfortunately
07-25-2018, 08:47 PM
#15