Nooooo, gearbox is dying!

[DiscoJeffster]

I knew this day would come.
Yesterday - went to accelerate from some lights, nothing. Car literally moved off at 1kph. It eventually started to go and then woke up, but then didn’t feel right. Later, noticed that changes were flaring, noticeable slippage instead of lock up when I know it would normally lock and get a boogie on. Very much not behaving as normal.

No dash errors, nothing logged in IID, including pending.

I do have a Zip kit to put through the valve body, filter, etc and new ZF fluid (20L) for a multi-fluid change so I’ll now do that and see if it helps. Really don’t want to spend $8000 on a rebuild!

274,000km.

[Pippin]

I knew this day would come.
Yesterday - went to accelerate from some lights, nothing. Car literally moved off at 1kph. It eventually started to go and then woke up, but then didn’t feel right. Later, noticed that changes were flaring, noticeable slippage instead of lock up when I know it would normally lock and get a boogie on. Very much not behaving as normal.

No dash errors, nothing logged in IID, including pending.

I do have a Zip kit to put through the valve body, filter, etc and new ZF fluid (20L) for a multi-fluid change so I’ll now do that and see if it helps. Really don’t want to spend $8000 on a rebuild!

274,000km.Sorry to hear that, the fluid you take out will tell you a lot. Good luck.

[PeterJ]

Not sure what sort of use the cars had as far as towing and everything but 274000, well I think that's not too bad. Hope your flush fix works out.

[ATH]

I'm getting mine serviced soon at 80K as I do tow a light van. Just a precaution really as it shows no sign of not working correctly....yet.
AlanH.

[justinc]

Did you check the adaptions? If it IS the transmission, I would expect to see a series of incorrect ratio or TC lock faults...

[DiscoJeffster]

Did you check the adaptions? If it IS the transmission, I would expect to see a series of incorrect ratio or TC lock faults...

I tried for some useful live values on the GAP IID today but couldn’t find any I could make use of. I’m not seeing any errors, and I agree, I’d have expected to see something, but maybe I’m overly sensitive and know the car, so maybe I’m sensing the issue before it’s flagging faults. It’s definitely not locking up as I’d expect it - noticing a lot more slushiness.

When you say check the adaptations, do you mean reset them and see if it helps, or check the adaptation stored values?

I’ve got the Sonax Zip kit plus all the other bits required to rebuild the valve body so I think I’ll give it a try. I don’t have new solenoids so I’ll be taking a bit of a punt that they’re ok. I guess if it doesn’t fix it I can pull the valve body again and fit new solenoids. At that point I’ll give up and get it rebuilt.

I just dropped nearly $10k on the engine semi-rebuild body off etc so if I can get the box to last another couple of years before I have to rebuild it, that’d help the finances somewhat.

[Graeme]

I wouldn't touch it until fault codes start being logged because if it doesn't work afterwards then you won't know if the original problem persists or whether you've created another problem. The cross-checking of shaft sensors etc will soon detect any faults.

Are any engine faults being logged?

How is the park brake?

[DiscoJeffster]

I wouldn't touch it until fault codes start being logged because if it doesn't work afterwards then you won't know if the original problem persists or whether you've created another problem. The cross-checking of shaft sensors etc will soon detect any faults.

Are any engine faults being logged?

How is the park brake?

No faults logged for anything. Park brake working perfectly. Definitely not behaving correctly though.

[josh.huber]

Brake light switch? I've been through 3 of them now. Same thing, car won't move. Also if the steering sensor is off. It won't take off from a standstill.
I don't always get the lights on when the brake light switch dies. Mostly not. I noticed at at busy roundabouts most. Then eventually the lights come on

[shanegtr]

Did you check the adaptions? If it IS the transmission, I would expect to see a series of incorrect ratio or TC lock faults...
I'd agree with this. When my trans failed I experienced similar issues to the OP and it logged incorrect ratio fault codes

[PerthDisco]

There’s a bunch of important seals that seem to age and give trouble in the ZF box as well. I’ve seen them replaced on different fix videos for different model cars with 6 speed and 8 speed.

Between the mechatronics unit and the gearbox body there are 3 rubber plugs and another rubber piece they call the goggles that are prone to failure and cause issues.

[Pippin]

There’s a bunch of important seals that seem to age and give trouble in the ZF box as well. I’ve seen them replaced on different fix videos for different model cars with 6 speed and 8 speed.

Between the mechatronics unit and the gearbox body there are 3 rubber plugs and another rubber piece they call the goggles that are prone to failure and cause issues.You get all those in a Mechatronic Seal Kit a must to replace when doing the valve body. It may also be worth replacing the Case Connector while your at it. Nick

[INter674]

There’s a bunch of important seals that seem to age and give trouble in the ZF box as well. I’ve seen them replaced on different fix videos for different model cars with 6 speed and 8 speed.

Between the mechatronics unit and the gearbox body there are 3 rubber plugs and another rubber piece they call the goggles that are prone to failure and cause issues.


Noooo..not the 8 speed surely🤤

. And I thought it was almost bullet proof..can't find any issues so far when dr googling the 8 speed..I only find compliments. Surely with millions of them out there some issues would be reported on the net😞

[justinc]

Noooo..not the 8 speed surely🤤

. And I thought it was almost bullet proof..can't find any issues so far when dr googling the 8 speed..I only find compliments. Surely with millions of them out there some issues would be reported on the net😞

I'm not concerned with mine... you shouldn't be worried..

[Eric SDV6SE]

ZF are bullet proof if looked after. The 8 speed even more so.
You need to replace the mechatronic seal, plus the vb to transmission seals are a must, and whilst youre in there the solenoids. Look after it and will look after you.

[INter674]

ZF are bullet proof if looked after. The 8 speed even more so.
You need to replace the mechatronic seal, plus the vb to transmission seals are a must, and whilst youre in there the solenoids. Look after it and will look after you.

At what ks approx should seals etc be replaced..I've done the fluid change at 90000 ks?

[PerthDisco]

I’m at 225k kms on ZF6 and coming up for third oil flush. Thinking now would be good time for the mechatronics service kit.

[Eric SDV6SE]

Hmm, good question. I had the first full flush done at 120k kms, then i rebuilt the vb at 160k km as the gear changes were getting harsh and reverse selection took a few seconds. I bit the bullet then and preventatively did the full vb overhaul inc new mechatronic seals, solenoids and steel pan, duoprene gasket etc.. Was about 1200 in parts including 20l of penrite BMV iirc.

Now at 200k km (199562 to be exact) and no issues. My recommendation would be at around 140-160 IF the fluid has never been changed, otherwise do it when you notice the gear changes getting harsh and gear selection is longer than a second or two.

I am planning the new full flush at 240,000km, so 80k km between fluid changes seems ok to me.

[DiscoJeffster]

Car was on its best behaviour today. Still, full valve body rebuild planned.

Just need solenoids

https://uploads.tapatalk-cdn.com/20200531/abe81f71e279db1f3c14a9acb610c990.jpg

[goldey]

Car was on its best behaviour today. Still, full valve body rebuild planned.

Just need solenoids

https://uploads.tapatalk-cdn.com/20200531/abe81f71e279db1f3c14a9acb610c990.jpg

DiscoJeffster

If not too much trouble would you please list out the parts that you've assembled for the valve body rebuild? I feel that our 2012 SDV6 is at 158k kms and the 6 speed is doing some 'strange' things. Are you doing the work at home or are you enlisting a reputable Indie to do it? I have rebuilt multiple engines and diffs, but never touched an auto before (box of black magic.......). When my old Series 1 Disco tdi ZF auto box destroyed itself I got a replacement done by my local Indie. Willing to give it a go with my newly acquired workshop manual if home doable.

Regards

Goldey

[DiscoJeffster]

Sure.
Note: I have the 6HP28 gearbox so internal parts are different to the 26 used on the 2.7L engines.

1 x Sonnax Zip Kit.
The Zip kit is a freshen up for the valve block and fixes most of the common internal leaks that occur from age related wear. It’s installable without and special tool and does not require reaming of bores etc. consider it DIY.

1 x Duraprene gasket. Obviously a new gasket to seal the pan. I have a steel pan.

2 x valve body separator plates. The 28 box had two models of separator plates (plates that seal the two halves of the valve block together. These generally need to be replaced as the rubber seal layered on them will be worn/brittle. I bought the two types so once I have it apart I’d have both alternatives and wouldn’t need to head out to find the one it uses. You can’t tell which one you need until it’s apart.

1 x mechatronic kit. Includes four seals plus the square seal, plus the external mechatronic seal. These should all be replaced as they go brittle, break and leak.

1 x Solenoids (not shown here). These are pulse width modulated (PWM) solenoids that control the oil flows. They do wear out, can leak and flow outside the parameters of the gearbox adaptations where it then impacts performance.

1 x filter. Obvious.


So the only issue this rebuild cannot help is if there is too much wear in any bushes causing fluid loss. Also cannot fix a worn out torque converter. The idea of this is that if the valve body is able to properly control the gearbox then there is less compensated wear in other components.

[loanrangie]

DJ does the zip kit not include the orings for the solenoids ?

[Pippin]

Sure.
Note: I have the 6HP28 gearbox so internal parts are different to the 26 used on the 2.7L engines.

1 x Sonnax Zip Kit.
The Zip kit is a freshen up for the valve block and fixes most of the common internal leaks that occur from age related wear. It’s installable without and special tool and does not require reaming of bores etc. consider it DIY.

1 x Duraprene gasket. Obviously a new gasket to seal the pan. I have a steel pan.

2 x valve body separator plates. The 28 box had two models of separator plates (plates that seal the two halves of the valve block together. These generally need to be replaced as the rubber seal layered on them will be worn/brittle. I bought the two types so once I have it apart I’d have both alternatives and wouldn’t need to head out to find the one it uses. You can’t tell which one you need until it’s apart.

1 x mechatronic kit. Includes four seals plus the square seal, plus the external mechatronic seal. These should all be replaced as they go brittle, break and leak.

1 x Solenoids (not shown here). These are pulse width modulated (PWM) solenoids that control the oil flows. They do wear out, can leak and flow outside the parameters of the gearbox adaptations where it then impacts performance.

1 x filter. Obvious.


So the only issue this rebuild cannot help is if there is too much wear in any bushes causing fluid loss. Also cannot fix a worn out torque converter. The idea of this is that if the valve body is able to properly control the gearbox then there is less compensated wear in other components. Where did you source your parts in Perth?

[DiscoJeffster]

DJ does the zip kit not include the orings for the solenoids ?

Yes it includes new o-rings for the solenoids but that’s not what goes wrong with them. They internally wear out. Even if their resistance is of spec, commonly vacuum testing will show they leak etc.

[PerthDisco]

Yes it includes new o-rings for the solenoids but that’s not what goes wrong with them. They internally wear out. Even if their resistance is of spec, commonly vacuum testing will show they leak etc.

Look forward to pics and hope goes easier than thermostat replacement [emoji23]

[Pippin]

Look forward to pics and hope goes easier than thermostat replacement [emoji23]Take care when you prise the two halves of the VB apart as mine fell apart when I picked it up after removing the bolts.

[loanrangie]

Yes it includes new o-rings for the solenoids but that’s not what goes wrong with them. They internally wear out. Even if their resistance is of spec, commonly vacuum testing will show they leak etc.

They would only leak if the orings have failed, i'd test them before replacing.

[DiscoJeffster]

They would only leak if the orings have failed, i'd test them before replacing.

No. There is a specific vacuum test that is performed to detect wear inside the solenoid which is nothing to do with the o-rings. The solenoids are a well known fault domain for poor shift control. Sure, stick with them but if you do all the work and it’s still not behaving, pulling it apart again to replace them? Stuff that. It’s also cheaper to buy a new set than three types of solenoid test kits plus a vacuum tester.

[DiscoJeffster]

They would only leak if the orings have failed, i'd test them before replacing.

Sonnax Solenoid Test Manifold Kit - 95430-VTK (https://www.sonnax.com/parts/4345-solenoid-test-manifold-kit)


“The leading cause of solenoid failure in Ford 6R60, 6R75, 6R80, ZF6HP19/26/32 (Gen. 1) and ZF6HP21/28/34 (Gen. 2) units is an inability to maintain an internal mechanical seal, resulting in a multitude of drivability concerns. Since it is not an electrical failure, it can be difficult to evaluate whether a solenoid is the cause of a particular problem.
Sonnax solenoid test manifold kit 95430-VTK allows quick, easy, cost-effective pass/fail verification of the solenoid's internal sealing integrity, taking the guess work out of replacing solenoids.”

[PerthDisco]

Sonnax Solenoid Test Manifold Kit - 95430-VTK (https://www.sonnax.com/parts/4345-solenoid-test-manifold-kit)


“The leading cause of solenoid failure in Ford 6R60, 6R75, 6R80, ZF6HP19/26/32 (Gen. 1) and ZF6HP21/28/34 (Gen. 2) units is an inability to maintain an internal mechanical seal, resulting in a multitude of drivability concerns. Since it is not an electrical failure, it can be difficult to evaluate whether a solenoid is the cause of a particular problem.
Sonnax solenoid test manifold kit 95430-VTK allows quick, easy, cost-effective pass/fail verification of the solenoid's internal sealing integrity, taking the guess work out of replacing solenoids.”

What do you reckon TransmissionRUs would charge to do this work?

[DiscoJeffster]

What do you reckon TransmissionRUs would charge to do this work?

No idea mate. Sorry. I guess parts plus about 4 hours labour? The trans fluid alone is enough. I’m going to do a triple flush with 20L of LG6. I’m switching back to LG6 after using an alternative. I’m not sure why other than I guess in the back of my mind I feel I might get more life from the box using it, but I can’t substantiate that at all.

[Eric SDV6SE]

DJ does the zip kit not include the orings for the solenoids ?

The zip kit improves the oem design by having two o rings for each end of line seal. This provides much better sealing. The kit also includes new clutch valve cylinder as these wear out. Finally, the zip kit also contains the accumulators with springs that sit at the end of each valve. The oem rubber top hats fkatten out and cause the harsh shifts as theres no spring in the system. This in turn causes wear on the vb and transmission. If the actusl clutch paks and torque converter are in good shape, a rebuilt vb will def. Improve driveabilty.

[Pippin]

The zip kit improves the oem design by having two o rings for each end of line seal. This provides much better sealing. The kit also includes new clutch valve cylinder as these wear out. Finally, the zip kit also contains the accumulators with springs that sit at the end of each valve. The oem rubber top hats fkatten out and cause the harsh shifts as theres no spring in the system. This in turn causes wear on the vb and transmission. If the actusl clutch paks and torque converter are in good shape, a rebuilt vb will def. Improve driveabilty.Having just fitted a Shift kit (TransGo) to my 6HP26 (Not a ZIP Kit which it should have been) The trans operates perfectly nice and smooth but I still have this problem:
On coast down for instance turning into a side road, if I accelerate to quickly as I straighten up I get a clunk (which seems to come from the diff) as if slack is taken up, it also happens in a straight line, if I delay the throttle a little its ok. I suspect a solenoid as I didn't replace them but it may be another cause. Any ideas would be appreciated. Nick

[INter674]

I think they all do that if you are coasting and hit the throttle..maybe just as the auto is down shifting. Our 8 speed does it occasionally..the TD5 did it more often.

[josh.huber]

Having just fitted a Shift kit (TransGo) to my 6HP26 (Not a ZIP Kit which it should have been) The trans operates perfectly nice and smooth but I still have this problem:
On coast down for instance turning into a side road, if I accelerate to quickly as I straighten up I get a clunk (which seems to come from the diff) as if slack is taken up, it also happens in a straight line, if I delay the throttle a little its ok. I suspect a solenoid as I didn't replace them but it may be another cause. Any ideas would be appreciated. Nick

Mine does it in such a way you can feel it. For me it's transfer case wear.. I've got one in the shed to put in when I get around to it. You need to drop shafts to isolate

[Eric SDV6SE]

Same here, to me its driveline wear. Transmission shift harshness is most noticeable if accelerating briskly, or downshifting in sport mode. The drivelibe is then loaded, so no freeplay like youd have when coasting and then applying power.

[Pippin]

Same here, to me its driveline wear. Transmission shift harshness is most noticeable if accelerating briskly, or downshifting in sport mode. The drivelibe is then loaded, so no freeplay like youd have when coasting and then applying power.I think you are all on the money! I'll do some investigation and post my results. Thanks.

[josh.huber]

Hey jeffster, do you want to sell your new left over solenoids and left over valve body separator?

Also I changed my transfer case. Had to lube the splines anyway. Wasn't the TC. I bought it really cheap but. So I'm happy to have a spare at the price I paid.

My zip kit has arrived I'm now getting all the gear together to do a "mid life"
Solenoids, zip kit, gasket, oil, seals etc

[DiscoJeffster]

Yes mate. I’ll PM you.

[Eric SDV6SE]

I see Sonnax is now listing the tooling for fitting oversize pressure control valves etc. This is the next step to prolong torque converter life

Checked my Penrite BMV filled ZF6HP28 the other day, after 40000km fluid still as new. Re- torqued transmission mount bolt to 175Nm, was about 1/2turn in it!

[josh.huber]

I have emailed sonnax to enquire about other work they recommend while I'm in there.. I get a drive line snatch that I thought was transfer case.. on off throttle bump. I'll post up what they recommended aswell as results after I fit the kit

[DiscoJeffster]

I have emailed sonnax to enquire about other work they recommend while I'm in there.. I get a drive line snatch that I thought was transfer case.. on off throttle bump. I'll post up what they recommended aswell as results after I fit the kit

I get that post rebuild. Always have. I believe it’s simply on off throttle transition

[Eric SDV6SE]

I get that post rebuild. Always have. I believe it’s simply on off throttle transition

Signal latency between throttle application, 21 ECUs and about a billion bytes of data being transferred before the car says "Ok, I'll go" after your foot asks for it.

[josh.huber]

Mine's not a delay. If I get on and off the pedal aggressively I can make it sound like something is coming through the floor. I have suggested to sonnax is in the application of the Torque converter. It's getting worse too.

[Eric SDV6SE]

I was reading on their website that bypass in the pressure control valve leads to lower than acceptable fluid pressure, so the tc does not lock up correctly. This is what an oversize pressure control valve can solve and save the TC.

[PerthDisco]

Mine's not a delay. If I get on and off the pedal aggressively I can make it sound like something is coming through the floor. I have suggested to sonnax is in the application of the Torque converter. It's getting worse too.

This?


Discovery 3 worn front propshaft - YouTube (https://youtu.be/yteUwg5--eA)

[josh.huber]

I wish, all my shafts are checked and new. I've spoken with sonnax a little and called around. I've been put on to a tranny expert who can vacuum test the valve body and they have machinists ect working there. They were so friendly to deal with and reasonably priced I decided to just take my valve body and parts to them. He could have supplied cheaper but I already have most of it.

I am getting the whole block vac tested. Before. Then after to see what was worn to help others with diagnosis.. Because I don't want to open it again.. I'm doing all the optional boost control valves etc at the same time. This bloke has the tools to do the job.

I'll post up my reports when I'm done.. He also buys and sells sonnax parts. Was very conversant in 6hp28 boxes. I only rang to see if he could vac test after I did the zip kit. He was so easy and cheap I just said **** it. Let's not mix this up. Do the whole valve body and give it back.

[PerthDisco]

I note in Perth Driveline in Osborne Park are the Sonnax and authorised ZF agent but I’ve never heard anyone use them for transmission work.

Home - (https://drivelineap.com.au/)

Interesting read - TECH - (https://drivelineap.com.au/tech/)

[PerthDisco]

Good valve body rebuild video of Sonax kit installation

CAR NINJA! Valve Body REBUILD - YouTube (https://youtu.be/CBhpwIWLBLg)

[TDV6Robvdw]

Good valve body rebuild video of Sonax kit installation

CAR NINJA! Valve Body REBUILD - YouTube (https://youtu.be/CBhpwIWLBLg)

Thanks for sharing 👍