Reflash ZF 850re Transmission after oil change????

Maximus Gladius

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Anybody heard of having to reflash your transmission after doing an oil change or flush on the newer Chrysler ZF transmissions?? -

My short story: My gladiator Rubi has 6500kms and I’ve come to learn from “ZF Service Information - Oil Change Kit for ZF 8HP Automatic Transmission”
- “ZF automatic transmissions are filled with specifically developed SEMI-SYNTHETIC oils. “

So that means that ZF Life Guard 8 is not full synthetic. Now then, short of buying a $40 bottle of it and running it to the lab to confirm, OR drawing a sample of it from the transmission and take that to the lab, I’m going with what ZF has published on their product sheet....for now.

This is not a plug for Amsoil but I know their Signature Series ATF is 100% synthetic so I enquired with my Amsoil distributor, as to if their ATF is compatible with this ZF 850re transmission? and yes it is. The concern back from Amsoil’s tech department was that if a flush or oil change is done, a reflash is necessary to reset the transmission to “relearn” the new oil”. I’ve never heard of this.

Amsoil stated a case they became involved with where a Dodge Charger was taken to a dealership and the work order had them swap out the Life Guard oil for Amsoil to which the service department did. A week later, the transmission suffered a catastrophic failure and Chrysler blamed Amsoil. Amsoil fought back and supported the customer and their product and Chrysler determined the tech that did the oil change forgot to reflash the tranny. Chrysler warrantied the transmission and Amsoil put up a bulletin stating it necessary to reflash the tranny. The bulletin has since been taken down. I will post a YouTube concerning the data pulled on the ZF’s oil.


check out: 13:21 and 18:17 but listen to the whole vid.

I’m not wanting to start any fights on what oil is better or I shouldn’t be touching this Life time oil good for the life of the tranny... I just want to stick to the question at hand plz.





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bgenlvtex

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I'm going to suspect that the reflash is setting pump parameters to compensate for different viscosity at different temperatures as I alluded to in the other thread, that is however speculation.

I personally would not ask them to reflash the computer just so I can use a different fluid unless there is solid empirical data to support the fact that the design fluid is inadequate. In doing so you are using unproven hypotheses to circumvent design function.

Will Amsoil go to bat for you if your transmixer shits the bed? Possibly, but is the juice worth the squeeze? Almost certainly not. Truck is down,litigation,more cash out of pocket than a replacement transmission. I just don't see the value.

I honestly think you are attempting to fix the unbroken, but if you feel compelled to do so have at it.

Have you attempted to contact ZF for their input? I strongly suspect I know how that would go on a couple different levels, but would be interested to hear he story regardless.
 
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Maximus Gladius

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I'm going to suspect that the reflash is setting pump parameters to compensate for different viscosity at different temperatures as I alluded to in the other thread, that is however speculation.

I personally would not ask them to reflash the computer just so I can use a different fluid unless there is solid empirical data to support the fact that the design fluid is inadequate. In doing so you are using unproven hypotheses to circumvent design function.

Will Amsoil go to bat for you if your transmixer shits the bed? Possibly, but is the juice worth the squeeze? Almost certainly not. Truck is down,litigation,more cash out of pocket than a replacement transmission. I just don't see the value.

I honestly think you are attempting to fix the unbroken, but if you feel compelled to do so have at it.

Have you attempted to contact ZF for their input? I strongly suspect I know how that would go on a couple different levels, but would be interested to hear he story regardless.
Glad you came over to read the whole story. My solid empirical data would suggest a semi-synthetic oil (ZF Life Guard) would fail in comparison to a full synthetic (several other ATF’s with SAME viscosity as ZF claim this, (however Amsoil is thicker viscosity )).

I am critically thinking this. I don’t think I’m going down an “unproven hypothesis”...in part.
There’s a lot of us drivers and self maintainers here that know a petroleum oil cannot perform as well and as long as a synthetic. ZF claims their transmissions have “semi-synthetic oils” in them. To me, semi ‘something’ means the other part of it is not, therefore we have a part synthetic and part petroleum oil in the “good for the life transmission”. Following me so far?

Let’s go to the extreme then and look at an engine oil that is strictly petroleum with no synthetic...they are usually good for 12 months or 5k or so before an oil change is suggested. So how can ZF claim the ‘petroleum’ side of their “life time” oil will have the same life expectancy as a full synthetic? Its ludicrous. They say that ZF Life Guard will last the life of the tranny. We also know death is a part of life so we can take comfort when we crack open the dead tranny in 100k or more that globby black shit will still be in there but sorry, it’s on the other side of the warranty time and were shelling out how much for a new one.

I haven’t pulled the pin yet and now that I think what happened in that tranny catastrophe in my opening post is viscosity related, I would at the very least do lab samples as we go along with the ZF but if I actually do change things out, it’ll be full synthetic and the same viscosity.
 

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Glad you came over to read the whole story. My solid empirical data would suggest a semi-synthetic oil (ZF Life Guard) would fail in comparison to a full synthetic (several other ATF’s with SAME viscosity as ZF claim this, (however Amsoil is thicker viscosity )).

I am critically thinking this. I don’t think I’m going down an “unproven hypothesis”...in part.
There’s a lot of us drivers and self maintainers here that know a petroleum oil cannot perform as well and as long as a synthetic. ZF claims their transmissions have “semi-synthetic oils” in them. To me, semi ‘something’ means the other part of it is not, therefore we have a part synthetic and part petroleum oil in the “good for the life transmission”. Following me so far?

Let’s go to the extreme then and look at an engine oil that is strictly petroleum with no synthetic...they are usually good for 12 months or 5k or so before an oil change is suggested. So how can ZF claim the ‘petroleum’ side of their “life time” oil will have the same life expectancy as a full synthetic? Its ludicrous. They say that ZF Life Guard will last the life of the tranny. We also know death is a part of life so we can take comfort when we crack open the dead tranny in 100k or more that globby black shit will still be in there but sorry, it’s on the other side of the warranty time and were shelling out how much for a new one.

I haven’t pulled the pin yet and now that I think what happened in that tranny catastrophe in my opening post is viscosity related, I would at the very least do lab samples as we go along with the ZF but if I actually do change things out, it’ll be full synthetic and the same viscosity.
I think it's a bit tough to compare engine oil vs. transmission fluid (think apples to oranges). Where is this solid empirical data you speak of?

The way I look at it--if ZF is putting in semi-synthetic and claiming it'll last the lifetime... Then leave it at that. I would trust a corporate with over $40 billion USD in revenue to have done their proper R&D.
 
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Maximus Gladius

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I think it's a bit tough to compare engine oil vs. transmission fluid (think apples to oranges). Where is this solid empirical data you speak of?

The way I look at it--if ZF is putting in semi-synthetic and claiming it'll last the lifetime... Then leave it at that. I would trust a corporate with over $40 billion USD in revenue to have done their proper R&D.
Where's the data to prove synthetic is better than petroleum? Are you suggesting there isn't because you're asking to see proof? I'm sure the stack of data proving that is out there. Do I need to go get it all to prove it here? I don't think so. Am I persuaded by marketing to then believe synthetic is better,... yes, partly and actually using product for the other part. I'm not a chemist nor an oil and gas engineer but I have driven and maintained my vehicles since the 80's. Synthetic oils in engine, transmissions, diffs, gear boxes and pumps have always out performed petroleum. There won't be too many people boooing me here.

Anyway, I was hoping to have my forum posted question answered about the reflashing. There's been a couple good guesses so far.
 

bgenlvtex

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Glad you came over to read the whole story. My solid empirical data would suggest a semi-synthetic oil (ZF Life Guard) would fail in comparison to a full synthetic (several other ATF’s with SAME viscosity as ZF claim this, (however Amsoil is thicker viscosity )).

I am critically thinking this. I don’t think I’m going down an “unproven hypothesis”...in part.
There’s a lot of us drivers and self maintainers here that know a petroleum oil cannot perform as well and as long as a synthetic. ZF claims their transmissions have “semi-synthetic oils” in them. To me, semi ‘something’ means the other part of it is not, therefore we have a part synthetic and part petroleum oil in the “good for the life transmission”. Following me so far?

Let’s go to the extreme then and look at an engine oil that is strictly petroleum with no synthetic...they are usually good for 12 months or 5k or so before an oil change is suggested. So how can ZF claim the ‘petroleum’ side of their “life time” oil will have the same life expectancy as a full synthetic? Its ludicrous. They say that ZF Life Guard will last the life of the tranny. We also know death is a part of life so we can take comfort when we crack open the dead tranny in 100k or more that globby black shit will still be in there but sorry, it’s on the other side of the warranty time and were shelling out how much for a new one.

I haven’t pulled the pin yet and now that I think what happened in that tranny catastrophe in my opening post is viscosity related, I would at the very least do lab samples as we go along with the ZF but if I actually do change things out, it’ll be full synthetic and the same viscosity.
Yep,yep I get it.

But what you are missing it seems is that the composition of the oil regardless of the base stock will demonstrate a range of viscous behavior across the range of service temperatures. The transmission was designed to function across the full range of temperatures with the viscous behavior of the specified fluid.

If you can source a full synthetic that mimics that behavior there may in fact be some virtue to it. But the very nature of the full synthetic says that will be virtually impossible. Hence the warning about other additives. Those additives alter friction, which alters temperature, which alters pressures, which may or may not result in catastrophic failure or just diminished life.

So, lacking full knowledge of what the transmissions expectations are for viscosity across the full temperature range, it is impossible to say that anything is better than anything, because we just don't know.

Can we say full synthetic is better than semi? In some circumstances yes we can when ONLY the physical properties of the lubricants are considered, or ONLY the performance of those lubricants is considered. In the case of an automatic transmission the function of the fluid is about providing predictable and repeatable friction. Decreasing friction is counter productive.

Think of it like this:
A specific fastener calls for 500 lb/ft torque. 575 lb/ft is not better. The simple fact that you are exceeding the specification does not make it better .

So in the end if you are following the manufacturers maintenance schedule, does it matter if the fluid will last 50% longer? No. The only reason that would matter is if you are going to extend the service interval and completely ignore the manufacturers recommendation. Beyond that, the service life of the fluid is a moot point.

I'm a proponent of UOA's when there is an identifiable and significant value. Spending $25 for a UOA with the intent of extending service intervals on an individual component, when the cost of servicing that component at the manufacturers recommended interval is almost the same cost as the UOA is dumb. Just change it.

In this case where you are talking about dumping the factory fill when virtually new, fully negates any economic value to be gained from the extended service interval theoreticallygained by changing to full synthetic. You would have to (on the first service) double the interval just to break even on the cost, that makes no sense at all.
 
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Yep,yep I get it.

But what you are missing it seems is that the composition of the oil regardless of the base stock will demonstrate a range of viscous behavior across the range of service temperatures. The transmission was designed to function across the full range of temperatures with the viscous behavior of the specified fluid.

If you can source a full synthetic that mimics that behavior there may in fact be some virtue to it. But the very nature of the full synthetic says that will be virtually impossible. Hence the warning about other additives. Those additives alter friction, which alters temperature, which alters pressures, which may or may not result in catastrophic failure or just diminished life.

So, lacking full knowledge of what the transmissions expectations are for viscosity across the full temperature range, it is impossible to say that anything is better than anything, because we just don't know.

Can we say full synthetic is better than semi? In some circumstances yes we can when ONLY the physical properties of the lubricants are considered, or ONLY the performance of those lubricants is considered. In the case of an automatic transmission the function of the fluid is about providing predictable and repeatable friction. Decreasing friction is counter productive.

Think of it like this:
A specific fastener calls for 500 lb/ft torque. 575 lb/ft is not better. The simple fact that you are exceeding the specification does not make it better .

So in the end if you are following the manufacturers maintenance schedule, does it matter if the fluid will last 50% longer? No. The only reason that would matter is if you are going to extend the service interval and completely ignore the manufacturers recommendation. Beyond that, the service life of the fluid is a moot point.

I'm a proponent of UOA's when there is an identifiable and significant value. Spending $25 for a UOA with the intent of extending service intervals on an individual component, when the cost of servicing that component at the manufacturers recommended interval is almost the same cost as the UOA is dumb. Just change it.

In this case where you are talking about dumping the factory fill when virtually new, fully negates any economic value to be gained from the extended service interval theoreticallygained by changing to full synthetic. You would have to (on the first service) double the interval just to break even on the cost, that makes no sense at all.
Now that’s and answer I can work with. Thanks for spelling that out.
 

bgenlvtex

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Now that’s and answer I can work with. Thanks for spelling that out.
Hope that helps and (A) that is only my somewhat educated opinion and should not be taken as gospel and (B) for my torque example it would be more clear if I had used the same torque value and lubricated or not lubricated as an example because that is much closer to what we are talking about here
 
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Maximus Gladius

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Hope that helps and (A) that is only my somewhat educated opinion and should not be taken as gospel and (B) for my torque example it would be more clear if I had used the same torque value and lubricated or not lubricated as an example because that is much closer to what we are talking about here
I got what you were saying about the torque spec. Your somewhat educated answer still provides a lot there to ponder and to ask about full synthetic with same property values. There’s plenty to consider here
 
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Have you attempted to contact ZF for their input? I strongly suspect I know how that would go on a couple different levels, but would be interested to hear he story regardless.
So, to be clear, I’m not promoting Amsoil, I’m just wanting a full synthetic for this ZF 85re tranny and I’ve now found out Chrysler/Mopar has published car manufacturer codes for oil companies to meet in order to be in compliance with ZF’s transmissions.

I asked my Amsoil dealer to reach out to Amsoil Tech to confirm Chrysler’s approval of their 100% synthetic ATF Signature Series oil and the reply back from Amsoil Tech is they didn’t go after an approval BUT their oil is in compliance with the codes. The list of codes on the 3rd pic is readable. The 2020 Gladiator Rubi falls under the first # “Chrysler Mopar 68157995AA”...

071489F5-FB5B-48D5-A030-BFED04E0B0BF.png


EAEC6BC1-178E-44CE-B07B-C542D8C54C3E.png


F01BBA30-48BE-48C9-ADE1-A41E04B2DC9D.png
 

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ZF has been in the transmission game for a long time. If their research showed that full synthetic would be better than the current formulation, they would be using it. I don't see the point in replacing the fluid with something not approved by ZF, just for warranty coverage, if no other reason. I do think a fluid change would be appropriate every 50k miles, to extend the life of the transmission.

The Allison transmission in my Duramax functioned better with full synthetic instead of the ATF supplied by GM, but that was a recommendation from Allison along with a specification for the fluid to use. It also had an external filter that was easy to change, along with a magnet to catch any loose metal particles.
 
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ZF has been in the transmission game for a long time. If their research showed that full synthetic would be better than the current formulation, they would be using it. I don't see the point in replacing the fluid with something not approved by ZF, just for warranty coverage, if no other reason. I do think a fluid change would be appropriate every 50k miles, to extend the life of the transmission.

The Allison transmission in my Duramax functioned better with full synthetic instead of the ATF supplied by GM, but that was a recommendation from Allison along with a specification for the fluid to use. It also had an external filter that was easy to change, along with a magnet to catch any loose metal particles.
I’d like to just make a note here to say I’m not reinventing something that hasn’t already been made available by Chrysler/Mopar. If you read the attached data sheet from Amsoil, on their published second page (3rd pic is cropped in to read the list better) Chrysler Mopar (and a multitude of other vehicles manufacturers) has a code spec that must be met by oil manufacturers) in order for their oil products to be “approved” for use in the 850re and other ZF transmissions and as you can see from the list, Amsoil met the requirements. If you also look just above that list and below, ZF is highlighted and Amsoil met those too. Amsoil didnt reach out to ZF to ask for their approval but ZF did reach out to all oil manufacturers with their codes to meet.

In my case specific, I always tend to lean toward “upgrading”, don’t we all. In this case, it’s oil. I’m not “pushing” Amsoil and I don’t sell it but I’ve used it a long time to know it’s very good and it’s 100% synthetic. My Gladiator has Amsoil...everywhere. I even dumped the power steering fluid and (before doing that confirmed what Amsoil recommended for the electric pump oil equivalent) and swapped it out and low and behold, the pump still works. I want things to run and operate better with full synthetic. I’m not looking to extend oil life though that is just what happens. All oil changes I do, a sample is taken to the lab for analysis and for my own records of maintenance I do this. The dealership and wrench monkey will rarely see this vehicle, if at all.

My first engine oil change was at 1000kms (621 miles). The lab sample showed “a trace of engine coolant” detected in the oil. Obviously I waited too long to get that factory shit out of there. I’m leaning toward contamination at the factory and not a head gasket leak. But next sample will be the judge. Levels haven’t changed in 5500kms.

You know from experience what your synthetic oil did for your tranny and your manufactured oil also met the code spec.
 

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I’d like to just make a note here to say I’m not reinventing something that hasn’t already been made available by Chrysler/Mopar. If you read the attached data sheet from Amsoil, on their published second page (3rd pic is cropped in to read the list better) Chrysler Mopar (and a multitude of other vehicles manufacturers) has a code spec that must be met by oil manufacturers) in order for their oil products to be “approved” for use in the 850re and other ZF transmissions and as you can see from the list, Amsoil met the requirements. If you also look just above that list and below, ZF is highlighted and Amsoil met those too. Amsoil didnt reach out to ZF to ask for their approval but ZF did reach out to all oil manufacturers with their codes to meet.

In my case specific, I always tend to lean toward “upgrading”, don’t we all. In this case, it’s oil. I’m not “pushing” Amsoil and I don’t sell it but I’ve used it a long time to know it’s very good and it’s 100% synthetic. My Gladiator has Amsoil...everywhere. I even dumped the power steering fluid and (before doing that confirmed what Amsoil recommended for the electric pump oil equivalent) and swapped it out and low and behold, the pump still works. I want things to run and operate better with full synthetic. I’m not looking to extend oil life though that is just what happens. All oil changes I do, a sample is taken to the lab for analysis and for my own records of maintenance I do this. The dealership and wrench monkey will rarely see this vehicle, if at all.

My first engine oil change was at 1000kms (621 miles). The lab sample showed “a trace of engine coolant” detected in the oil. Obviously I waited too long to get that factory shit out of there. I’m leaning toward contamination at the factory and not a head gasket leak. But next sample will be the judge. Levels haven’t changed in 5500kms.

You know from experience what your synthetic oil did for your tranny and your manufactured oil also met the code spec.
The point I was making is the full synthetic upgrade was recommended by Allison, where what you are planning is not specifically recommended by ZF.
 
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Maximus Gladius

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The point I was making is the full synthetic upgrade was recommended by Allison, where what you are planning is not specifically recommended by ZF.
I would assume that would be tough to get.
I’m repeating a lot here and as I posted at the very start, I have a question about the need to Reflash the tranny when an oil change is done?? I also said this forum isn’t about what oil is better, it’s not about selling a certain oil, and it’s not about others telling me I shouldn’t change the oil. It looks like people don’t read but to be fair and kind I engage with my Jeep family and try my best to be cordial.

As I pointed out, my Amsoil dealer went to Amsoil Tech and asked, “where’s the approval from ZF to use our synthetic ATF in the ZF tranny’s? Our customer wants to see it.” Reply back from Tech, “we don’t have it nor went after one. What we have is the specific code for the Chrysler Mopar ZF tranny they published that oil manufacturers have to be in compliance with in order to use our oil in that tranny”.

If you will,... consider an approval to use the oil (what ever oil) if it’s in compliance to the code.

I need a beer, and it’s only 10am
 

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What we have is the specific code for the Chrysler Mopar ZF tranny they published that oil manufacturers have to be in compliance with in order to use our oil in that tranny”.
Well, if you're quoting Chrysler specification code as authorization to use the alternate oil, then you need to use the Chrysler answer when they admitted fault after the tranny blew in your story above:

"Chrysler determined the tech that did the oil change forgot to reflash the tranny."

Therefore, yes, yes you do need to re-flash the tranny after an oil change.
 

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