Everything I've read, including posting emails from dealer service departments, says not to. One when so far as to say that staunch maintenance owners get really nervous at 100,000 miles and demand the change. Why would you change it? There is no reason to.

Do you own an 04 or newer XJ8? Did you own the previous incarnation XJ8? 1998-2003? If so, which do you like better?

 

Change it, at 50,000 mile intervals if possible. One need look no further than the archives of this, or any other Jaguar XJ8 user group, to establish a sense of the failure rate of ZF5HP24 transmissions used in 4.0 litre V8Jaguar models.

 

ZF also says the LifeGuard fluid for the 6HP26 is lifetime - not sure if "lifetime" extends beyond 100k or 150k miles.

It is quite costly tough - the cheapest I could find (online) was $37/quart and you need 6 (ormaybe7). Dealers charge as much as $99/quart.

There is also a TSB for an "ook" sound comming out of the trany which recomends replacing one quart or the trany fluid with LigeGuardPlus - no idea what that costs.

 

Where can you get LifeGuard Plus? Internet searches get me bathing suits!

 

To change or not to change that is the question, wether it be nobler!!
oops wrong site.

Change the fluid

 

Sorry the correct name is LigeGuardFluid6 and LifeGuardFluid6+.
LifeGuardFluid6+ is the fluid that goes in the Audi Q7 version of 6HP16 and the 6HP26A61 that goes in Audis with W12 engine. Jag P/N is C2C 37157. ZF p/n is S671 090 281 (this is 20 liter canister).
The TB for the trany noise is JTB00070

 

Correction: I don't remember where I read that tha additivementioned in JTB00070 is in fact LifeGuardFluid6+, but I might be mistaken. Use the correct Jag part number mentioned in the TB.

 

I agree with JagTechOhio, the fluid in the tranny is good up to about 60,000 miles according to ZF's own rebuild website (which is double normal, pretty amazing really!), but it should be changed in advance of this. What you read and hear from the dealer is wishful thinking and marketing, there is no such thing as a ZF 6 speedtranny that does not trash fluid over time and miles, no matter how good the fluid is. There is still friction material getting into it and incredible shear forces heating and decomposing it, bearings and friction plate steelsshucking metallic debris in it, rubber o-rings shearing material into itand so on.The tranny might make it 100K if you are lucky if you don't change the fluid. That's what the 98-03 XJ8 folks are finding anyway.There is a difference in the fluid from the 03 to the 04, but it is not that great, and it allows the squawk as the E clutch sticks, requiring a friction modifier to fix it,it allows a declutching shudder after stops ( haven't heard the reason for this yet) and so on, humans made it, and it has limitations, in fact, it'sgot more problemsthan the 4 speed ZF unit in my 96 as far as operation is concerned!Anything called "lifetime" is an obvioustrick, it means only "as long as it lasts", it does not mean your lifetime. I can't understand why we can't seepast this. Only the folks that want to keep their cars will change it, the original owners will sell them and it will be owner #2's problem, not Jags, notthe dealers, the owner.

 

Just had my tranny flushed as part of the squawk TSB @ 40K miles. Not only is the squawk gone but power hook up is noticeable and shifts are a lot smoother. Regardless of "lifetime fluid or not," I would strongly recommend a change out.

 

Did the Dealer do the flush? Did they flush it or just drain and refill? Did it cost extra and ifso how much? Wha tfluid was used? Sorry for all the questions, but not many have done this as far as I know.

 

They flushed and refilled under warranty. No cost.

 

Man, that is a lot of expensive fluid down the drain.

My xj8 is at 80k, I had a slight pan gasket leak and the dealer replaced the seal. They said the fluid was still good and used the original one and topped with 1 quart.

 

Actually, it's not expensive fluid down the drain because there was a TSB stating that there was a newer fluid that takes care of a squawk coming from hard gear changes...which the flush and fill with the uprated fluid actually fixed.

 

May be I don't quite understand what flush is. I was under the impression to flush means - drain the fluid, replace with new, drain again and replace with new. That's twice the fluid required.

The TSB you mention, calls for replacing only 1 quard of the fluid with a new one, the rest stays in the trany. Anyway these are unimportant details.

I think it is very naive to think any particular fluid is guaranteed for life. Except when "life" means - until the manufacturer warranty expires.

I need to find a ZF shop around Seattle and ask them about the trany service.

 

Just remember this MONEY is the moving and decision making force. If you ask someone who sells fluid they will tell you, yes change the fluid. ask someone who replaces or rebuilds parts they will tell you, don't change the fluid. It depends on you. Asa wise man once said "pay me now or pay me more later." Your choice. BTW there is no such thing as lifetime unless your married to Gilbert Godfreid

 

A true flush for an automatic transmission means to replace all the fluid under high pressure. This takes a special machine which most dealers have. They put the new fluid in it, connect it up to the ports and the old fluid is forced out and replaced with the new. The pressure dislodges gum and varnish. This is why some folks will not flush a tranny if it has over 75K on it, they are afraid of dislodging too much stuff and jamming the valve body or worse. There are also machines that will do a fluid replacement, which works by using the car's input shaftoil pump to transfer the old fluid to the machine and let the tranny iteslf suck in the new fluid through the tranny cooler lines. This gets the job done without the high pressure.

 

I keep seeing references to TSB JTB00040 Version 2 and that it has been replaced by TSB JTB00070 and JTB00071. Dealing with the whoop/squeal and adding an additive to the trans. I have searched all over and cannot find these TSB's. Does anyone know any links or can post these? I have a ZF 6HP26 and am in the process of changing the oils and pan.
Pete
Vero Beach, Fl.

 

I posted this information in a previous post about the transmission fluid in the XJR -ZF Transmission. "I own a 2004 XJR, with 62k miles. I did some research, and called ZF North America directly at 1-847-478-6868. Spoke with a very nice gentleman name Steve, who knows the ZF6HP26 very well. Steve gave me a distributor for the ZF fluid, since it is hard to get other than from the dealership who is charging $51 per quart in Northern Va. I spoke with a gentleman name Nat at Erickson Industries 1-800-388-4418; they are a distrbutor for ZF Transmissions and fluids. Nat said the fluid can ordered through him for $23.12 per quart. This is a much better alternative to the Jag dealer."

 

My transmission is shifting very well with no problems but after reading here might be time to get a quote to change as its done over 107000 miles!