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zf6 slip fix


dat111

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hey yall.

currently trying to band aid an issue with my box (i have a 2nd box laying around) but trying to get max life (plus learning as i go) 
out of curiosity. has anybody played with transmission line pressure? eg if i was to increase 6th gear would it help holding it in gear?
 its  6th gear is slipping an then it trys to shift backwards an goes into limp mode it gives me an incorrect gear ratio 6. 
just thought i would post up on the group incase another person is having an issue they may be able to learn also. 

attached is 6th gear line pressure i have added .5 (nothing has been flashed in as of yet) 
also have added 0.1 across the board from 2500 onwards  with shift pressure 6>5,5>4>4>3
 

272814314_668429944193253_163157895068966412_n.jpg

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When you log currently, does 6th line pressure match up with what is in the tune? Reason I ask is trying to ascertain if it's your frictions that are fried or you may have a cracked piston / leaking seal etc. If it's just fried frictions and you already hitting commanded pressure (check your log) then you might get lucky. But if you have a split piston / leaking seal etc and it can't even hit commanded pressure now then I don't think you will have much luck. Nothing to lose, give it a go man. 

On a side note, even though it sux your box needs a rebuild, you are lucky in that you can make all kinds of random adjustments to see what it does without caring if it destroys itself. I'd take this opportunity to learn as much as you can about the ZF. Can I borrow your car for a month :) 

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Can't beat destructive testing!

We had a lot of fun testing out anti lag with our 220,000km old stock GT3582. We discovered (lol) that you induce shaft droop with minimal effort in your local carpark. We also discovered that the housing and compressor will finally make love after many years of sexual frustration.

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32 minutes ago, Roland@pcmtec said:

Can't beat destructive testing!

True that lol. I had a dead stock zf with just a tune and cooler handle 950awhp on the street! It eventually broke but lasted many months over 800awhp. The key to it lasting was not shifting it at WOT, just send it while in gear and backing off for shifts.

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hey lads. just an update. i have bumped up the line pressure. its deffs done something right.
currently in the process of looking at how much a new box will be (3k rebuilt) including TC service. 
 

in the meantime. im gonna have a go at dropping the pan, doing the valvebody sleeves/bridge seal/meca sleeve, new filter an some zf oil in it! 

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@Roland@pcmtec i have not.  i have spoken to a builder who also tunes. he said at the pressure its bumped upto (1.5 bar over standard) that it should be pretty hard kicking into gear. which its not. he said, dont bump it up anymore. 

but its maybe worth logging the pressure i guess. trying to understand the logger is bloody hard! 

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What I'm thinking out loud is if you can monitor the 3 adaption phase values and know the maximum upper adaption range, then that can guide you as to what areas to increase. Assuming box is sound, but needs a bit of help to hold back 400+rwkw on radials. 

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hey all. i had a fiddle around with the logger an found "adaptations" on the forum. 

from my uneducated guess. clutch E is pretty much toast, the rest are "okay" after going a quick google... on beemer forums they say that a box will still function under 700mbar 
after 326km on the box. i understand that wear is gonna be happening regardless. 

i havent logged line pressure as of yet.. does anybody know the actual ZF DMR is for the trans pressure lines? 

 

273183004_1040224146527863_57977306982499452_n.jpg

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Lol, 600 is pretty high. Each clutch has an adaption limit. Haven't found what they are yet. But the fact your is an even number strongly suggests 600 is it for the E clutch haha.

There is a bug fix in the works to fix the line pressure value. It is out by a factor of 100. This is what I log. Should help you out.

image.png.784be64e3759aaf8ab96e5ad30ec604a.png

 

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22 hours ago, hjtrbo said:

Lol, 600 is pretty high. Each clutch has an adaption limit. Haven't found what they are yet. But the fact your is an even number strongly suggests 600 is it for the E clutch haha.

@dat111 try logging these using the latest logging template in 2.10 to get values to confirm. It'll also confirm if the 600 value is the E clutch as mentioned by @hjtrbo
Make sure you're using the latest 2.10 Version
I could be wrong but I think the German logging names may have been updated in the new logging templates. Values in the new template are in PSI but the unit can be changed
image.png.9e2605e11334edced43cbef97aca9f78.png
 

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thanks guys!! 
just playing around with tunes at the moment. kinda chucking stuff at the wall an seeing what sticks posted a photo below which was taken yesterday, comparing the "wear data"

seems that its cut one of them in half. unsure what is going on.
before i install the old box i have sitting around. im gonna try do the sleeves an bridge seal. see if that has any benefit on the wear numbers (or in fact its truely toasted) 
an fill it up with Penrite BMV (36 dollars for 4 litres via work)

273062422_725950281724330_2649312057592444314_n.jpg

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1 hour ago, Puffwagon said:

This makes a box slip. I learnt the hard way when I used it.

Gulf western syn-ts is what I use and recommend.

I agree... bmv not good.  Have tried about 6 different oils transguard complete ok, penrite lv ok just change them out every 40k or so or when driven hard... i.e.  numerous runs at 120dec c oil temps.  

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Thanks for the response everybody! 

I realised even with staff discount 20 litres of gulf western is cheaper then 12 litres penrite BMV so I've decided I'll opt for gulf western. Syn TS an do the sealing sleeves,bridge connector an what not just to see if there any improvement 

I've also attached a video, that's another box I picked up for $450. Anybody got knowledge if that front shaft should be like that? I've asked a few people I've gotten a mixed answers. Box has 128km on it. 

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  • 2 weeks later...

should give an update on the new box i got i guess. hasnt been fitted. 

with some knowledge of people, an pulling off the trans sump it actually looks really clean inside there!!  spotless you might as well say!!
i also had a recommendation from puffwagon about the syn-TS.. i opted for the LV, i put another fella onto it. he suggested its better then the LG fluid.  

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  • 2 months later...

Hey guys,

Just looking through this thread as my ZF has started slipping 3-4 and clutch e is maxing out adapts.

I recently changed my trans cooler and topped up with Penrite BMV.

Is my trans cooked now or would changing the oil to lifeguard or gulf western potentially fix the issue?

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9 minutes ago, Dolan said:

Hey guys,

Just looking through this thread as my ZF has started slipping 3-4 and clutch e is maxing out adapts.

I recently changed my trans cooler and topped up with Penrite BMV.

Is my trans cooked now or would changing the oil to lifeguard or gulf western potentially fix the issue?

Is this one thats you have tunned? Or are you referring to standard

Does it have a pressure leak, if so do your three seals.

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15 minutes ago, BeerTurbo said:

Is this one thats you have tunned? Or are you referring to standard

Does it have a pressure leak, if so do your three seals.

I’ve made the shifts slightly faster and made the converter lockup in 2nd a lot sooner, around 1k rpm.

 I’m not sure if it has a leak, what 3 seals are you referring to?

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i have had some beer so my memory is not on point.

there is a bridge seal and three circle seals thats seal liquid from the top trans casing to the megatronics.

 

i the transmission is slipping in gear - have you played with the line pressures? if the pressure does not meet the target you might have a leak. if you have bad adaptations you might have a solaniod issue.

 

if it during the change, maybe put your shift times back up. or increase your tq reduction during shift. my 3-4 shift on terry was pretty bad but increasing the min TQ reduction time for the 3-4 shift helped this heaps.

 

 

 

 

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1 minute ago, BeerTurbo said:

i have had some beer so my memory is not on point.

there is a bridge seal and three circle seals thats seal liquid from the top trans casing to the megatronics.

i the transmission is slipping in gear - have you played with the line pressures? if the pressure does not meet the target you might have a leak. if you have bad adaptations you might have a solaniod issue.

if it during the change, maybe put your shift times back up. or increase your tq reduction during shift. my 3-4 shift on terry was pretty bad but increasing the min TQ reduction time for the 3-4 shift helped this heaps.

Haha, I’ll have to look at that if I take the box apart, I do want to try ‘fix’ it for now with it together if possible.

I haven’t played with the pressures at all, nor have I checked the pressure vs target. I will need to check them.

I’ve had these trans changes for over 2 years so far without issues, I think I’ll try increasing tq reduction timing and the main shift pressures and see where that leads me.

Would changing the fluid help me at this point?

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5 hours ago, Dolan said:

I recently changed my trans cooler and topped up with Penrite BMV.

Did the slipping start after changing to BMV or was it doing it prior? I've seen a few that have started slipping after changing to BMV. The Gulf Western Syn TS LV is a good option.

The seals leaking/bleeding off pressure is common & if you're going to change the fluid, do the seals at the same time.

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2 hours ago, Bill said:

Did the slipping start after changing to BMV or was it doing it prior? I've seen a few that have started slipping after changing to BMV. The Gulf Western Syn TS LV is a good option.

The seals leaking/bleeding off pressure is common & if you're going to change the fluid, do the seals at the same time.

It only started slipping a month after topping up the fluid. It could’ve been on its way out before that but I never data logged anything major trans related before then.

Yeah I defs will while I’m there.

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Dolan,

Engaging 4th gear uses the E-Drum - its calle the dredded e-drum for a reason.  For the oil to pressurise the e-drum it passes through the centre of the pump stator. There are teflon seals that keep the oil pressurising the E-Drum.  On the other side there is a bush that stops the oil passing.  So you rely on seal ring and a bush to maintain good pressure on the e-drum.  Most people keep increasing the pressures in the tune to compensate, but alas its a bandaid if the bush is worn or seal rings are not working properly.  Then you have clutch wear to deal with.  Then there is the valve body itsekf and internal accumulators.  I replace all bushes, install new accumulators and vac check the valve body.  Use Penrite LV or Lifeguard - ive had good success with either.  change the LV regularly.  Hope this helps? 

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  • 1 year later...

Hi guys bit of a thread mine but this thread had some awesome info (especially those youtube videos) and my problem is related.

My wifes stock G6ET started off throwing a ratio code (P0729 Gear 6 Incorrect Ratio) with load in 6th. I took it for a drive and managed to also get one in 5th (P0735 Transmission Gear #5 Incorrect Ratio). The car has been driving otherwise fine and is completely stock with 160k on it.

I have logged the adaptations to try and get an idea what might be happening. I can't seem to get the clutch name to show when logging - any tips there?

If I am guessing the letter correctly Clutch E adaptation is maxed out.

The box had a small fluid weep a while back (loose pan bolts) - I have not re-checked fluid level.

Am I right in jumping to the conclusion that the most likely scenario is a cooked E clutch?

image.png

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Yep definitely a service first before opening up the trans. Do not use Penrite BMV it will make the trans slip. Use GW Syn TS.

Gears 4,5 and 6 use the E clutch, that is where you can add 0.6 bar to the whole shift pressure map to correct the 0.6 bar it's adding. After that you can do a adapt reset and see where it ends up again. Don't worry about clutch B, that is for reverse so won't matter if you reset it.

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Fluid levels were good. ATF was the blackest I've ever seen 😲 I'd put 12L of Lifeguard through it 50k kms ago and it's mainly been doing school runs.

Speaking to a few shops, the root cause is a bushing on the shaft feeding the E clutch which wears, causing a pressure leak and then clutch slip. Being a mechanical failure bumping the line pressures would not do much, if anything, for long.

It's in for a rebuild now 😢

 

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