Brutal,

With all the recent folks changing or considering changing their S-Type's transmission fluid during the past few months, I thought I'd ask your opinion on when to do it.

Our owners manuals all say the fluid is "lifetime", but what does "lifetime" really mean? Some of these cars are carefully driven and pampered all their lives. Some of these cars are driven like a bat out of hell every day during the commute to and from work. And some of these cars fall squarely in between.

Our S-Type is well-cared-for. It is never abused. It is never raced or floored. It is never J-gated. It does twice as much highway mileage as it does city mileage. It does not exhibit characteristics of "the lurch". It continues to run its factory fill of ZF Fluid (Shell M1375.4 mineral oil) and by the time my wife gets back from Florida with it next week, it will have approximately 44,000 miles on the odometer.

So when should I start thinking about changing the transmission fluid just for routine maintenance purposes and to help minimize the risk of transmission failure down the road? With a normal vehicle that runs typical transmission fluid (by that I mean no more than $6 or $8 per quart regardless of what type or brand of fluid is specified for it) and is easy to drain-and-fill, I would probably start thinking about changing the fluid somewhere between 75,000 and 80,000 miles. But this S-Type is not a normal vehicle. The fluid is a wallet-killer and the procedure is far more difficult in scope than just a typical drain-and-fill.

So what do you tell your customers, Brutal? I realize that every case is different, but I'm just looking for a guideline here.

As always, thanks for your consistent and valuable contributions to this forum....

 

Your car will just love that kind of journey. Pretty kind to the tranny, I'd think. But like you I'd like to know Brutal's opinion or indeed any other tech opinions.

We hear the horror stories about car problems on forums, which probably makes things seem far worse than they actually are, of course.

I was on another (non-jag) site where things could look scary sometimes but the actuality was that most cars lasted about 150,000 miles and 10+ years. Mine did more and I never needed to change its ATF, though I half-planned to. It had a traditional dipstick, and I kept a close eye and nose on the fluid - very reassuring.

I've been tempted to try to acquire a used STR ZF box cheaply and store it. If I had the covered space I'd go for an entire crashed car.

 

My 11 year-old 1999 Dodge Ram pickup still has its factory fill of Chrysler ATF+3 at just under 58,000 miles. Still shifts like a dream and the fluid remains bright red with no visible or smellable impurities. No plans to change the fluid anytime soon, but that transmission is known for being bulletproof for decades....

My wife's 2004 Lexus RX330 AWD gets a drain-and-fill every 30,000 miles because the previous RX300 AWD transmissions were known to be underengineered with high failure rates after only 50,000 to 70,000 miles. Each drain-and-fill exchanges 4 to 5 quarts of fluid, enough to ensure that about half the fluid is new, and costs me $25 to $30 using Toyota Type T-IV fluid. Don't even have to jack the vehicle up in the air to do it. Takes all of 20 minutes, start to finish, and most of that time is just waiting on the last few drops to finally drain out....

These S-Types are more like brain surgery in both cost and complexity when it comes to changing the transmission fluid. I hope the techs will chime in here with their opinions and recommendations for us. One thing is for sure - these ZF units should come equipped with dipsticks....

 

I'm not Brutal, apologies, and know he'll weigh in too, but since you've opened it up to others:

I'm of the opinion (opinion being the operative), that changing is better than leaving it. You have to interpret seal for life carefully. Think of who Jaguar (and other car companies) is talking to. They're talking to their customer, the first owner. The average first owner (and ideal owner to Jaguar) buys new, keeps the car approx. 4 years or 50K miles then trades in on another new one. To that customer Jaguar offers an almost maintenance free product. Other than oil changes, which Jaguar provides for free, the rest of the units are sealed for life. Legally, that definition and subsequent obligation by Jaguar ends at 50K miles/4 years. If you doubt it, try a seal for life argument with Jaguar if your transmission fails at 51K miles.

I've serviced a number of 5HP24s and 6HP26s. To me, there is nothing that much different about the mechanical technology in thes transmissions than there was in the previous generation transmissions where regular preventative maintenance was recommended. The only glaring one is the use of Synthetic fluids which does extend change intervals. But, nothing last forever.

Dealers need to and will speak the company philosophy which is drive it until there is a problem then we'll replace it. It is a remove/replace at the unit level instead of unit repair company policy. So they're speaking correctly to you as the second, third, nth owner, just as long as you can afford the $6K, $7K unit replacement cost.

That doesn't mean they're not going to break down when you change fluid anyway, I just believe it helps extend the "End of Life".

 

I guess it's kinda like how on a box of cereal they'll tell you that it has a certain number of servings per box. If you look at what they consider a serving to be, it's usually nowhere near the amount anyone actually eats. But, it is what they (the company) are basing their statement on. All the same, I hope more techs post up on this subject. (I like gaining more knowledge.)

 

According to the ZF list of lubricants, its sealed for life unless there is severe driving. If thats the case, the interval is 50 to 75k miles or 8 years. I believe people claim that Jag recommends 100K intervals (but I have not seen this in writing.

I believe that babying a transmission actually makes things worse since shifting at lower RPM causes more torque stress. I had a 04 T6 Volvo XC90. First transmission at 30k miles, second at 15k miles. First was driven normally, second was babied. Assuming that the accelerating rate or speed is the same, then the input power and output power of the transmission is equal (ignoring losses). Since power = rpm * torque, higher gears imply lower RPM and higher torque to the input of the transmssion, increasing the stress.

For the Jag, I believe that using the sport mode and a bit more throttle causes the adaptive software to shift at higher RPM, reducing the transmission stress with a slight reduction in MPG. Unlike the old solid 3 & 4 speeds, the newer 5, 6, 7, 8 speed transmissions are designed to shift sooner at lower RPM to improve MPG.

Besides needing to pump in the fluid and the need for an IR temp meter, the process is rather straightforward. The down side is its a bit more complex however, the process is faster with less uncertainity about it being under or overfilled. In my experience, it takes forever to get a good dipstick reading after pouring fluid down the tube to top it off. Also, the process of checking the fluid - engine hot after at least xxx miles and taken with the engine running in P leaves quite a bit of uncertainity in under or over filling. In both cases, a large amount of fluid remains after a drain and fill.

The real leap of faith is in the selection of the fluid. I believe there is really just 4 choices

1) ZF lifeguard 6** (or Jag factory stuff). Made for the the transmission, partial synthetic oil*** and very expensive.

2) Pentosin* (true synth, right color, doesn't meet ZF6 shell spec, big base of BMW users, $10-12/qt, mail order)

3) Redline (true synth, wrong color, claims ZF6 shell spec, not used by too many, $9-11 qt, easily found locally)

4) Castol (non synth, wrong color, claims ZF6 shell spec, cheap, used by a few)

* Pentosin claims ZF ML11B spec in their datasheet. According to ZF list of lubricants, its in a list with the lifeguard5 and the Esso fluid (Esso to ZF5 as Shell to ZF6). There is a website that claims pentosin is shell compatible but I can't find any claims from pentosin to back this up

** ZF has a ZF-ML11 spec but it seems to be used for the lifeguard, 5,6, and 8 fluid. Approved non-ZF fluids from ZF only applies to ZF5, can't find any info for ZF6.

*** There seems to be different grades of synthetic oil. I believe redline and pentosin are made from the more expensive stock. Zf calls it's stuff a partial synthetic oil. Shell has a process to turn "mineral oil" into a low grade synth oil. Because the process still has a wide variation, the shell process based oils can be called synthetic in the US but can't in Europe. I guess thats why its called a "mineral oil". Funny how Jaguar calls it "mineral oil", references the Shell spec as a requirement, and ZF calls it a partial synthetic oil - proves that selling price and cost is not related.

I think it comes down to this. If you think using a fluid that meets Jag's requirement (shell spec) and a synth fluid is a requirement, then the redline is the way to go. If you go by what most people have used and liked (mostly BMW guys), then pentosin is the way to go (BTW, if you think the ZF5 spec fluid is ok for the ZF6, there are many other options). If you go by what ZF says, then the lifeguard6 at 2.5-4x the cost is the way to go. If you don't care about synth. fluid and care about the Jag spec, castrol is the way to go (1/2 the cost). With the pentoin or redline option, its cost is pretty much inline with most transmissions.

 

Some great information guys, thanks for sharing. I've added this thread to the FAQ for you s-typers, plus added a few of those pdf links to our Xk8/R FAQ. Great addition.

 

I pretty much agree with these statements. At our dealer we were told specificly DO NOT do flushes of transmissions unless we want to pay for the trans. Its not that its harmfull, its that we live in a dishonest, and a take a pill to fix everything society. On the dishonest side, and Ive seen this stuff happen and I just shake my head at peoples charector or lack there of....
Joe blow comes in with a shifting or other issue with his trans, wants a tranny flush, we do it, and suddenly he's in the service managers office stating that before WE worked on the tranny it worked fine. Now it slips, or doesnt shift right,etc.....and wants a new trans. It takes an awfull lot of profit from flushes (not the full cost) to pay for this situation. Then there is the 1 pill fixes all syndrome. You have a tranny issue and are told that it may or may not do anything, sign that you understand. Then when it doesnt fix your problem, suddenly that paper doesnt meen you "REALLY" understood and want your money back.
Or lets see a tranny flush now gives me a "warranty" against trans problems down the road right!!!!!
Also you reach a time when you should NOT do a fluid change. When you let it go so long, the fluid is dirty and the trans seals worn(it still works fine) you change the fluid with clean new fluid and now the seals can no longer seal clean non dirty fluid and now you do have trans issues. I actually had this happen to me. I knew it was risky, so I saved the old fluid, drained it, changed it and bingo, I couldnt back it up, only forward, pushed it back in the stall, drained the new fluid, and put the old back in. It worked fine and sent the customer on their way(no it wasnt a Jaguar, but you get the point)
These are ALL issues delt with all the time at dealers, I dont make this crap up....
My personal feelings are...is "If were my ZF, I would change the fluid as a full flush with new pan(which is the filter) every 60k, or I would at least do a drain and fill every 30k....

 

Thanks for all the comments, guys. These 6-speed ZF transmissions are spread around in a number of different cars by different manufacturers, and every one of them seems to have their own care-and-feeding recommendations. Finding something that works for me is going to require some compromise somewhere. I don't think I'm willing to compromise on the fluid, however. Mixing fluids could turn out to be a recipe for disaster.

If our transmission O-ring sleeve never develops that pesky and expensive leak, I expect to just do drain-and-fills with our S-Type for as long as we keep it. I haven't decided on the mileage interval. I'd like to see the cost of the ZF Fluid come way down first. It's come down in my neck of the woods by about $10 per litre since I bought the car in December 2008.

So Brutal, when you do just a drain-and-fill of a 6-speed ZF, how much fluid can you typically expect to drain out of that transmission plug once it's pulled? And is that plug really plastic or polyethelyne, not metal?

 

its plastic, and about 4-5litres for a drain and fill. If you leave it over night, you can expect to get at least another litre to drain overnight.

 

Thanks, Brutal. Never heard of a plastic drain plug on a transmission before....

 

The 6 speed ZF can come with a plastic pan with integrated filter but it is also supplied to other car manufactures with a steel pan. I don't know why the difference?
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The steel pan version is used on the 6HP28 trans, I believe and is not installed in Jaguars as far as I know. I think the 6HP28 is a truck application version. I cannot answer for very late model cars (08, 09), so I comment with those conditions.

BTW - on a 6HP26 wet drain (pan drained, removed, but not torque converter) I am getting about 7 1/2 qts. More than Brutal saw. I've measured it a couple of times and I am confident. The ZF wet refill calls for 8 qts. which adds up because you're going to add more fluid than needed cold running, then as the temp rises, spill about a half qt. If you only purchase 5 qts of replacement fluid you might find yourself running out to buy more in the middle of the job. When I just pull the plug and not the pan I get about 6 1/2 qts with over 1/2 qt. sitting in the filter, the other half draining from the trans if you let sit for awhile, or you do the trans drain from a cold car sitting over night, as Brutal commented.

 

Castrol's website clearly states that their Castrol Import Multi-Vehicle ATF has been tested and cleared for Jaguar use in applications requiring Shell M1375.4 mineral oil such as the 6-speed ZF units in our S-Types.

I called Castrol and spoke with their technical service department to attempt to gain a better feel for whether or not this is true. They claim the Castrol fluid is indeed mineral oil-based, just like Shell M1375.4. It is red in color as opposed to golden-colored for our OEM fluid. The cost differential is by far the largest attraction - this Castrol fluid can typically be purchased for $5 or $6 per quart at many of your local auto parts stores.

Is anyone out there running this Castrol fluid in your 6-speed ZF? If so, I'd sure like to see a synopsis of how long you've used it, how many miles you've used it, and what your general perception is regarding whether or not the product is indeed a sufficient substitute for the ridiculously-expensive ZF Fluid....


I found a local source here in Raleigh that sells ZF Fluid for the 5-speed ZF units. It's about $22 per litre. They don't yet have access to the ZF Fluid for the 6-speed ZF units, but they expect access sometime during 2010. I plan to check with them every couple of months and stay on top of how this turns out....

 

Jon89, thanks for posting that.

 

I just spoke with ZF Customer Service in Chicago. They told me about a transmission parts distributor out of Louisville, Kentucky called Whatever It Takes Transmission Parts (WIT for short). WIT's corporate office is (877) 634-5699, and their website is wittrans.com. They have branches around the country. The closest one to me is 2.5 hours away in Charlotte where joycesjag (Rick) lives. They currently sell a 1-litre bottle of 6-speed ZF Fluid (also called Lifeguard 6) for $38.08. To date, that's by far the best price I've ever been quoted for the OEM fluid....


For what it's worth, ZF Customer Service states that "under normal operating conditions", their fluid is good for at least 100,000 miles....

 

Check one of the other post's out someone has found a complete fluid change special around $230 I believe. Thanks Paul 2004 STR

 

Has anyone tried a dipstick conversion for the ZF trans?

5HP24 Dip Stick

Benefits? Drawbacks?

 

has anybody used this redline product as replacement for the shell in the 6sp ZF? ive always heard good things of redline
Red Line Synthetic Oil - Gear Oil for Manual Transmissions - D4 ATF

 

Fellow member ccc did.

Here is his awesome write up:
https://www.jaguarforums.com/forum/s...ics-faq-30991/