Your experience: ZF Auto transmission failure after non recommended oil change to Box.

GT!

New member
Hi Fanatics. So after searching through numerous threads and seeing differing opinions. I wanted to see from personal experience how many of us have experience catastrophic 😄 box failure by changing oil anyway despite being advised after diagnosis that the box is not in spec and requires a rebuild. So are the different levels of “damage” of “not in spec” OR if it’s even slightly out out spec, the box is damned to a rebuild. Your first hand experiences please? Thank you.
 

Sleepa

Member
I have a 6hp28, was advised by ZF to not do the oil change at 108xxxkms, raced the car Michellin cup two years ago, finally rebuilt the box at ZF last year on 182xxxkms.

If you box is giving issue's get XHP, you will get safely another 40-50xxxkms out of the box when the software is done.... activate line bump in the software and your crisp gear changes return...
 

GT!

New member
Don’t have first hand experience, but I would listen to the experts (in this case OEM).

If you have trust issues, I guess the current special is a perfect opportunity for trial and error.
Thanks for the response. I always like to listen to the experts. I do however think we all can agree that for example with regards to dealerships the solution to fix the issue, more often than not, is to throw parts/rebuilds (and very expensive ones at that) to fix a relatively "small" problem. I do have trust issues hence this post :) I was hoping to benefit from someone else's trial and error. I have no serious issues with my box and to my mind it drives perfectly. To be told that at 180xxx KM an oil change is not recommended due to a diagnostic printout is what is worrying me.
Thats why i was hoping for some first hand experience if any.
Thanks again appreciate your input.
 

GT!

New member
I have a 6hp28, was advised by ZF to not do the oil change at 108xxxkms, raced the car Michellin cup two years ago, finally rebuilt the box at ZF last year on 182xxxkms.

If you box is giving issue's get XHP, you will get safely another 40-50xxxkms out of the box when the software is done.... activate line bump in the software and your crisp gear changes return...
Thanks for your response. If I may ask, what lead to you needing it rebuilt at 108xxxKM's. Was it total failure? I have seen posts regarding the software, and guess what I'm asking is what about doing the oil change and the software? Maybe my technical understanding here is what is causing the trust issues OR the hope that there is a proper cheaper cure :cool: .
 

Sleepa

Member
Thanks for your response. If I may ask, what lead to you needing it rebuilt at 108xxxKM's. Was it total failure? I have seen posts regarding the software, and guess what I'm asking is what about doing the oil change and the software? Maybe my technical understanding here is what is causing the trust issues OR the hope that there is a proper cheaper cure :cool: .
108xxxkm's - ZF gave me a diagnosis with shift times and adaptation values showing the box was out of spec. It had not failed yet but the shifts were no longer crisp and it felt like a slip was developing during daily use.

Loaded XHP at 108xxxkms and drove / raced it for another 74xxxkms till it needed a rebuild! Rebuilt on 182xxxkms and man its epic now!

Possibly a partial oil change would work? Some new mixed with some old?

My advice.... Load XHP and enjoy it.... till it fails properly.
 

R!Yo

Staff - Social Media
Staff member
Hi Fanatics. So after searching through numerous threads and seeing differing opinions. I wanted to see from personal experience how many of us have experience catastrophic 😄 box failure by changing oil anyway despite being advised after diagnosis that the box is not in spec and requires a rebuild. So are the different levels of “damage” of “not in spec” OR if it’s even slightly out out spec, the box is damned to a rebuild. Your first hand experiences please? Thank you.
Have you contacted ZF Services (our forum advertisers) and got their opinion?
 

GT!

New member
Have you contacted ZF Services (our forum advertisers) and got their opinion?
Yes I have. Their diagnosis is its out of spec and only a rebuild will fix. They say do not do an oil change as it "might" make the box worse. My question is has anyone had catastrophic failure after doing a oil change even though it was not recommended?
 

KPM3_30

Moderator
Staff member
My question is has anyone had catastrophic failure after doing a oil change even though it was not recommended?

Even if you get 10 responses that no one had an issue despite being advised against it, you may be the unlucky sod that tries it and the box bombs out. If you want to take the chance, pay R3.8k and get it done but have the R30k for a rebuild in your pocket should it fail.

I would suggest you either do a mixture of new oil into old, in varying ratios over time or just leave the box and save a bit every month to eventually rebuild it. I would personally spend the oil change money on XHP and save for the eventual rebuild.
 

individj

Well-known member
i recall reading a post here about someone doing the service and the box breaking not long after...
 

GT!

New member
Even if you get 10 responses that no one had an issue despite being advised against it, you may be the unlucky sod that tries it and the box bombs out. If you want to take the chance, pay R3.8k and get it done but have the R30k for a rebuild in your pocket should it fail.

I would suggest you either do a mixture of new oil into old, in varying ratios over time or just leave the box and save a bit every month to eventually rebuild it. I would personally spend the oil change money on XHP and save for the eventual rebuild.
Thanks for the response and I appreciate your suggestion. I would however feel better being the unlucky sod if there where 10 others posting that had a positive outcome. I’d just feel my odds would be better :)
 

Jakes4R

Member
I have also read about all of the warnings with regards to changing the oil in the gearbox if there are already issues.

I believe oil changes to auto boxes are what oil changes are to an engine : you do it as a preventative measure, to maintain and protect the parts to ensure proper functioning. If the damage is done, it's done. Oil can't repair damage, but some fresh oil might prevent further damage.

That being said, I think it is necessary to distinguish between an oil change and a flush. An oil change is only replacing what you can drain from the gearbox sump, while a flush is a total oil change (sump and converter). From my reading, most of the issues experienced after an oil change stems from a gearbox flush where all the oil was replaced.

I think these auto boxes can definitely have varying degrees of damage. They read a value and compare it, so it can be 3% out of spec or 15%. I suspect there is a threshold value for recommending a service or rebuild, but I have no idea what the threshold is.

How close/far a gearbox is from spec values probably plays a big role in how the gearbox will be affected by an oil change/flush.

I did an oil change (about 5 liters) by myself in December last year without having the values read. The gearbox is still fine, shifts are also still the same. However, I didn't have issues prior to the oil change - no jerky shifts, no slips, no gear selection issues. The oil inside still had a brown tint to it, it wasn't completely black and burnt. These are the factors I took into account before going ahead with the oil change. I didn't have issues and I want to keep it that way by doing a preventative oil change.

You'll know better than us what your gearbox is doing or not doing, but an oil service will not reverse any issues/damage.

It does sound like you are in doubt about your gearbox being 100% - in that case just leave it until it gets worse and you can't hold off a rebuild any longer.
 

GT!

New member
Thanks for the response. I acquired a 320d that has been pretty well maintained besides the the gearbox oil change. The mileage is 180xxxkm and to my knowledge without a transmission oil change. I love the car and would like to do as much preventative maintanence as possible. Gear changes presently are acceptable IMHO but the question I asked which you touched on is would the oil change be preventative or catastrophic. Thanks again for your personal experience and advice.
 

///M Individual

Well-known member
Hi Fanatics. So after searching through numerous threads and seeing differing opinions. I wanted to see from personal experience how many of us have experience catastrophic 😄 box failure by changing oil anyway despite being advised after diagnosis that the box is not in spec and requires a rebuild. So are the different levels of “damage” of “not in spec” OR if it’s even slightly out out spec, the box is damned to a rebuild. Your first hand experiences please? Thank you.

No first hand experience bud.

But look at it this way.....ZF could take your service money and expect you to be back soon after to take more of your money for a rebuild if they wanted to.

Instead they giving you expert advice to not service which shows they have your best interest at heart. I personally think do not tempt fate and save for the eventual rebuild like others have said.
 

GT!

New member
No first hand experience bud.

But look at it this way.....ZF could take your service money and expect you to be back soon after to take more of your money for a rebuild if they wanted to.

Instead they giving you expert advice to not service which shows they have your best interest at heart. I personally think do not tempt fate and save for the eventual rebuild like others have said.
Or they could just be speeding up the rebuild instead of trying to prevent it. Sorry for being cynical but that is also a scenario.
 

Solo Man

Well-known member
I made use of ZF's special about two years ago when i think they charged R3k for a new filter and replacing of gearbox oil that drained out. Upon asking i was told that the special did not mean a complete oil change but a partial oil change as they do not put the gearbox on the oil pump system whereby they replace all the old oil with new oil. I think they changed about five or six litres of gearbox oil on my car. That means that some two to four litres of old oil was still in the torque converter and cooler.
 

sash

///Member
Personally I asked alot of questions when I was at ZF, but even prior , did alot of reading on the forums about the service. At some point I was also reading ZF documentation in relation to how intelligient the box+software and how capable it is , of masking a possible problem. This implies that while the box might drive fine, it doesn;t mean everything is good, the software is good at masking the issue. The other thing is that by the time you start to notice an issue, its probably gone too far in terms of a service helping.

My take is that ZF is analysing the oil in order to gauge how much wear and tear has already occurred ( from last service if it was serviced). The more particles in the oil, the worse it is. The problem is that the particles in the oil affect the way the clutches work and offer some form of friction ( a good thing in worn gearboxes). If the wear is past a certain point, removing the oil with its particles will affect how the gearbox works. By the time the gearbox adapts to its new oil ( keep in mind with worn clutches resetting the trans adaptions is not recommended), it would cause extra (faster) wear of the clutches. The only time ZF recommends resetting gearbox adaptations is when rebuilding, or there is little or no signs of wear.

The grey area is that ZF can only determine the spec based on oil and adaptations of the gearbox. The gearbox adapations and quick charge times is the only thing they can use without stripping the gearbox apart.

THere was some documentation from ZF that i read some time ago about the specifications and what is considered to be just out of spec, but I assume the guys in germiston would already be aware of this. If your is on the border of being out of spec and i was in your shoes, i would do the service.
 

Kyle

///Member
No first hand experience bud.

But look at it this way.....ZF could take your service money and expect you to be back soon after to take more of your money for a rebuild if they wanted to.

Instead they giving you expert advice to not service which shows they have your best interest at heart. I personally think do not tempt fate and save for the eventual rebuild like others have said.
ZF are safe guarding themselves by warning of potential damage that could be caused by an oil change really.... They don't want people claiming a rebuild from them because the box was "damaged" during the service.

Another point to remember is, the total capacity of the ZF6 is around 20l (could be a few liters off), and you are only replacing 6l during the service.
 

Avir

Member
Hi guys.
Sorry to bring this old topic up.
But would like to know from the “D I Y” guys,what after market oil can one use for the zf 8 45hp box.
I was told dexron 3 will work.
 

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