ZF Gear Change Slip

[G6ETURBO]

Hi, I'm getting some slip in 2-3 and 3-4 down load  mainly and on light-medium loads. I turned down ZF00900 (Nominal slip table) down by 50 on all light loads, Went for a drive and the issue had gotten alot worse. Does this stuff need time to re learn in those areas before i start to feel changes?

 

Thanks.

[hjtrbo]

Probably a bit out of line replying as I'm still learning so take none of this with any salt at all.

Still yet to peak through all of the ZF DMR's in the logger but if you could find these...

From w

From what I've (lightly) researched these figures are supposedly a quick way to check the over all health of the box. As I believe any bullshit that is out there, if they are significantly elevated they indicate wear / leaks etc in each of the valve circuits. I've heard numbers thrown around that something under +/-700mBar is ok but I've yet to look into it more so this is all hearsay. The UK forums are good for this sort of info if you are bored and want to dig some more. 

In lieu of you fixing it or someone else getting involved, I guess in your case to rule out your ZF tune, you could take everything ZF back to stock temporarily, reset the adapts using ZF03182 (search for how to do it) and drive for a few hundred k's gently and see how it goes. Also check DTC's with Forscan.

 

[hjtrbo]

I reckon these are the ones. I'd be interested to see what yours are?

[G6ETURBO]

Hey mate, thanks for the information. I have attached a photo of those parameters on the logger. these numbers did not move as i was driving just stayed the same. Can send log if you would like.

 

 

[hjtrbo]

Cool, next step is to work out if they're in range or not. Forum search time.

Won't hurt to throw up a log. Could even by the converter you know...

Make sure you've got turbine speed and engine speed.

[hjtrbo]

Page 31 and onwards of the attached 'bible'

Your e is just out of range. Not used in 1st and 2nd so not your complaint.

And also some other resources that you might find helpful to read when things at work get a bit slow...

https://www.bimmerfest.com/threads/zf-transmissions-full-workbook.907228/
https://www.bimmerfest.com/threads/zf-transmission-adaptation-values-tracking-comparison.961306/
https://www.audiworld.com/forums/a6-s6-c6-platform-discussion-58/interpreting-tiptronic-adaptation-values-what-your-gearbox-telling-you-2973888/page5/
https://www.youtube.com/watch?v=20Wz03GFa5k
https://www.youtube.com/watch?v=QEz1caz0loM

ZF_Workbook-transmission-6-8HP.pdf

[G6ETURBO]

I'm actually only gettiing this slip when the box is cold. I cant find the exact table to up line pressure with lower temps to try and fix this issue. Would you by anychance know which tables i should be looking at?  Also could my numbers be out of range at all due to it being a 6r80 Built box.

[Bill]

On 8/5/2021 at 9:58 PM, G6ETURBO said:

Hi, I'm getting some slip in 2-3 and 3-4 down load  mainly and on light-medium loads. I turned down ZF00900 (Nominal slip table) down by 50 on all light loads, Went for a drive and the issue had gotten alot worse.

Have you compared the G6E strategy to a F6 or XR6T strategy?

 

12 hours ago, G6ETURBO said:

I'm actually only gettiing this slip when the box is cold. I cant find the exact table to up line pressure with lower temps to try and fix this issue. Would you by anychance know which tables i should be looking at?  Also could my numbers be out of range at all due to it being a 6r80 Built box.

I'm only a novice & taking a guess here, so if you try any of the below & are successful, please let us know what worked.

If you were to log the ZF temp to determine the temperature at which the slip occurs & is no longer present, you could compare that against these tables & make adjustments.

Note: Some parameters are still in development & require the workshop version to see them.
Even if you're unable to view or change the parameters, I recommend datalogging temp so you know when the issue occurs & at what temp it's resolved.

Someone with more experience might be able to comment on this.

[G6ETURBO]

9 hours ago, Bill said:

Have you compared the G6E strategy to a F6 or XR6T strategy?

I'm only a novice & taking a guess here, so if you try any of the below & are successful, please let us know what worked.

If you were to log the ZF temp to determine the temperature at which the slip occurs & is no longer present, you could compare that against these tables & make adjustments.

Note: Some parameters are still in development & require the workshop version to see them.
Even if you're unable to view or change the parameters, I recommend datalogging temp so you know when the issue occurs & at what temp it's resolved.

Someone with more experience might be able to comment on this.

No i haven't done that.

Unfortunately i only have the professional version so im unable to view those parameters. But i will log the temp and find out exactly when its happening. 

Will playing around with Nominal Slip time (ZF00884) and maximum shift time (ZF01636) be able to help at all? 

Edited October 23, 2021 by G6ETURBO

[hjtrbo]

Slips when cold but not warm. Something is mechanically wrong. I'd be willing to put a pineapple on it being your valve body to case seals. Can be changed at home, under 2 hours to get done. 

https://mjproducts.com.au/shop/landrover-zf-6hp26-genuine-valve-body-seals-plus-adapter-seal-block-and-mechatronic-plug/

https://mjproducts.com.au/shop/ford-non-genuine-zf-6hp26-6-spd-steel-pan-conversion-kit-10-litres-of-oil/

 

[Bill]

9 hours ago, hjtrbo said:

Slips when cold but not warm. Something is mechanically wrong. I'd be willing to put a pineapple on it being your valve body to case seals. Can be changed at home, under 2 hours to get done. 

https://mjproducts.com.au/shop/landrover-zf-6hp26-genuine-valve-body-seals-plus-adapter-seal-block-and-mechatronic-plug/

https://mjproducts.com.au/shop/ford-non-genuine-zf-6hp26-6-spd-steel-pan-conversion-kit-10-litres-of-oil/

 

I was thinking this was a possibility too. I wonder how long ago the 6R80 box was built, if it's a relatively new problem or if it's always been an issue @G6ETURBO

[G6ETURBO]

Box was built just under 2 years ago, I have had the issue for the past 5-6 months.

 

Thanks @hjtrbo I will take it back to the guy who built my trans to take a look as its still under warranty.

[hjtrbo]

Is your box properly built or just rebuilt OEM? That will change things as a properly built box likely has extra clutches and different clearances etc so will require tuning by an expert.  

If just an OEM rebuild then by all means take it back. A stock strategy on a stock box should not have issues between cold and hot. Back in the day when the car was new, it would have gone back to the dealer as a warranty claim for this behavior. 

[G6ETURBO]

Its properly built with extra clutches.

[hjtrbo]

Righto. You're in a different league. Disregard everything I've said.

[Bill]

10 hours ago, G6ETURBO said:

Box was built just under 2 years ago, I have had the issue for the past 5-6 months.

If the box was built 2 years ago but only started having the issue in the last 5-6 months, then the ZF tune was working ok.

 

10 hours ago, G6ETURBO said:

Thanks @hjtrbo I will take it back to the guy who built my trans to take a look as its still under warranty.

Have a chat with the bloke who built the box, let him know about the issue & get his opinion on whether it's possibly got a valve body to case leak as this is still a possibility.
As suggested by @hjtrbo it could also be the tune. The box now has some running time & although it may have been working ok when new, with a little wear, the tune may need adjusting.

[Bill]

5 hours ago, hjtrbo said:

Righto. You're in a different league. Disregard everything I've said.

The valve body to case leak is still a possibility. The box wasn't slipping for well over a year from what we've been told.

[G6ETURBO]

@BillIm going to take it in next week to see what he says about it. 

 

I done a few tests over the past few days in regards to it being temp related, It seems to be the first 3-4 Shift after key on (when cold) is the only time it will slip. After that first 3-4 shift if i slow down then go for another 3-4 shift its fine. Other than that first shit i cant fault the box at all its been really good.

[Bill]

4 minutes ago, G6ETURBO said:

@BillIm going to take it in next week to see what he says about it. 

 

I done a few tests over the past few days in regards to it being temp related, It seems to be the first 3-4 Shift after key on (when cold) is the only time it will slip. After that first 3-4 shift if i slow down then go for another 3-4 shift its fine. Other than that first shit i cant fault the box at all its been really good.

If it only does it once & is ok after that, you might need to leave the car overnight so it can be checked & datalogged when cold.

[G6ETURBO]

Yeah thats the plan, Also im trying to log the Trans Torque in NM. Does anyone know the right paramter to log for this. I tried logging Trans input torque but thats not the correct one. 

[G6ETURBO]

If i reduce E Clutch Boost time slightly in the tempertures im feeling the slip could that potentially help, Along with increasing Shift pressure tables 34 on low loads.

[hjtrbo]

3 hours ago, G6ETURBO said:

Yeah thats the plan, Also im trying to log the Trans Torque in NM. Does anyone know the right paramter to log for this. I tried logging Trans input torque but thats not the correct one. 

 TQ_NET might be worth a look...

3 hours ago, G6ETURBO said:

If i reduce E Clutch Boost time slightly in the tempertures im feeling the slip could that potentially help, Along with increasing Shift pressure tables 34 on low loads.

Sorry man, no help here, but I wanted to wish you were in GM world, you'd have no problem getting sorted with the changes and / or direction that you need. Don't know what it is about Ford land but the guys that know the info rarely give it up. A great example of this is a reputable workshop I deal with has openly given me pointers on getting my HSV tune closer to optimum and allowed me into their tune. But when I try to move the conversation towards my XR6T, the lips go tight.

Roland will shoot me for this next bit, hope he doesn't read this post... Back in the day HP Tuners had just enough to get the job done before PCMTEC came along and blew them out of the water. Long shot, but check out their forum. Also, grab their software (free) and a stock ZF strategy from their repository and check out some of the tables they mapped with regards to temperature just like Bill previously mentioned above. Whilst HP have nothing in the range of tables PCMTEC does, they only mapped the basics which sometimes can be a blessing as less can be more, you might get lucky.

For example there are 3 tables that HP tuners has that relate to trans temp and shift pressure that might help. 1 of them you already mentioned (boost time) and Bill is on the right path

For example, A clutch or 1-2 shift || HP tuners -> PCMTEC

Boost Pressure || TCM41880 -> ZF00734 

Boost Time || TCM41870 -> ZF01729

Upshift Offset || TCM41771 -> ZF01446

 

[G6ETURBO]

First photo is the first gear change to 3/4 then a moment later with very similar temp is the second 3/4 gear change. Very different calculated slip times. for some reason it was only logging the trans so all the other numbers are the same.

 

@hjtrbo Thanks for that info mate appreciate it.

[hjtrbo]

You really need an expert to chime in here and guide you. In lieu of that, happy to throw some random shit at it.

Is it only the first shift of the drive (when cold) that does it? Clutch purge? 

Tangent, when tuning my 6L90 shift pressures I log trans slip. Very helpful to determine if my oncoming or off going clutch needed adjustment or overall shift pressure. In this case I just slowly bumped up shift pressure 5% at a time.

Also logging the clutch solenoid currents could help you to spot some patterns. I would log those at high resolution. Logging those will give you insight into on-coming / off-going clutch relationship.

 

 

[G6ETURBO]

More than happy to listen to some random shit!

Correct, Only happens on the first shit. The next 3/4 shift is fine. Would you happen to know the trans slip parameter on pcmtec for logging. Also applogies for the questions im still learning all this, In my case when the box is warm the shifts are good, I will make some adjustments in ZF01454 Shift 3-4 Offset at the lower temps and see if that gets me anywhere. I did make some slight adjustments to ZF01733 Boost time clutch e, Lowered the time at lower temps but dont feel asif it made a change, mind you im only lowering by 20 so also unsure if that would be noticeable or not.

[hjtrbo]

I just used the old school way to get trans slip. Created a math parameter input speed / current gear ratio - output speed. You can export your log to excel to make this with  a lookup table based on current gear PID to get the gear ratio. There is likely a trans slip PID but I haven't looked for it yet. 

Also, see if there is any clutch purge things you can see. Won't be in front of the laptop for a few days so am flying blind. 

The symptons are pointing towards a piston / circuit that is not getting the fluid it needs first up and then is properly filled after the first actuation. 

[G6ETURBO]

Hi All, Since this issue i have had to get a new set of clutches in the box. My Adaptations prior to the rebuild are as per the attached snip. with only doing 500k's on the box with the new clutches i am having harsh downshifts from 4-3 and also Reverse. I am just wondering how long the learn process usually takes as even after the 500k's my current adaptions are:

-39 mBar

-250 mBar

-182 mBar

-190 mBar 

-490 mBar

this is a built box with 6r80 internals and extra clutches.

 

@hjtrbo I saw some posts you have made regarding adaptation temperatures and reducing values to ensure the box is within the adaptation threshold. I am running a PWR exchanger and my temps usually are sitting around 84-87c. Just wanted to confirm if these are the correct tables relative to the adaptation thresholds.

[Puffwagon]

Take some pressure out of the shifts so it shifts normally, then add it back in later if needed. Drop it by 10% at a time as this will get you in the ballpark after a few flashes.  I found my built box would bang or thud into gear with gentle to normal driving, until I dropped a bunch of pressure out of it.

The opposite is needed for WOT, you'll have to up it like a mofo depending on how much power you're making.

[G6ETURBO]

1 hour ago, Puffwagon said:

Take some pressure out of the shifts so it shifts normally, then add it back in later if needed. Drop it by 10% at a time as this will get you in the ballpark after a few flashes.  I found my built box would bang or thud into gear with gentle to normal driving, until I dropped a bunch of pressure out of it.

The opposite is needed for WOT, you'll have to up it like a mofo depending on how much power you're making.

All shift pressures are standard in normal shifts, only upped for sport mode under high low/rpm, however the line pressure for low load is at 7.6 in 3rd and 4th, would it be worth lowering below stock for the shift pressures or try lower line pressure l?

[Puffwagon]

Line pressure is what holds the clutch pack together after the shift has been made. You add line pressure if it slips while in gear, you would rarely remove line pressure.

If the shifts aren't smooth at low loads and low to medium rpm, you have too much shift pressure.

I would start by lowering shift pressures. It is fine to lower them as much as needed to get the shifts smooth again.

[G6ETURBO]

On 9/30/2023 at 2:55 PM, Puffwagon said:

Line pressure is what holds the clutch pack together after the shift has been made. You add line pressure if it slips while in gear, you would rarely remove line pressure.

If the shifts aren't smooth at low loads and low to medium rpm, you have too much shift pressure.

I would start by lowering shift pressures. It is fine to lower them as much as needed to get the shifts smooth again.

Okay i will get this updated and report back with how it goes. Thanks for the help.