Hi,
I would like to ask this group for their opinion on the above title.
I have a 2004 XJ8 with 50,000 miles on it, I have owned the car from new and taken care of most maintenance myself, and after recently replacing rear air struts with new Arnots ( work fine but I was a bit miffed to discover after install that you loose the CATS electronic adjustment feature and the plug in merely fools the ECU that all is well, but I must say they ride fine and at $450 a pop a slightly better deal than the Bat **** Crazy price of Jaguar OEM's at $2400 each, sweet mary !) , then all rear linkages, brakes and re-building the air suspension compressor by myself ( thank you " BagPipingAndy". I have decided to keep the car till death do us part. The car is black on black and is perfect, not one ding or scratch in or out.
I have the all too common droopy headliner to attend ( not looking forward to that one bit), I have the annoying intermittent wiper habit of the wipers stopping mid flight ( and having narrowed that down to a wiper motor replacement have decided to live with it because that sounds like a job from hell and this 70 year old body has it's creaky limits.

I know the trans and diff are supposed to be sealed for life and maintenance free but I am not so sure. I have had no transmission or differential issues at all.

Should I get into the tranny and diff if so :

Just drain the tranny and fill through side fill hole with Pentosin ATF 1 ( now superseded by ATF 6 or is there a better option and should I change the drain plug and the gasket on that plug?
Drop the tranny pan and replace the filter strainer and gasket at the same time.... I know this would be the ideal thing in a way BUT the tranny is drip dry and I hate to crack the seal open if I can help it.
Do I just leave all alone and do nothing?

And the diff, should I drain and re-fill and if so with what oil or should I let sleeping dogs lie.

Thank your for your thoughts and recommendations.

 

According to Jaguar & anyone with common sense, the trans is definitely not sealed for life (death, if you prefer). Lots of info on here about it.

 

These cars come with a plastic pan, & filter combined.
They will start to leak, & need to be replaced eventually.
You could wait until it starts leaking to change.
Or do it before, but it will leak eventually, needing to be changed.
Used a metal pan, with the proper filter on both of mine
Heavy duty Ford, metal & rubber, transmission gasket.
Both of mine were leaking when they were purchased.
Probably one of the big reasons they were traded in.
A transmission fluid, with filter change is rather pricey, of so i read

 

Definitely due to be replaced. I use a Mitey Vac to serice differentials. They use oil and not grease. Vacuum out the oil and replace with fresh lube. If my failing memory is intact the Jag uses 75-w140. Most are full synthetic now.
I used the plastic pan and filter on my tranny service. MerCon SP used to be the cheap substitute for ZF- Lifeguard 6. But is almost the same price now.
I used to have three vehicles with the six speed ZF transmission. Sold one. But it is a one and done service. BTW replace the Mechatronics sleeve while pan is dropped. BMW strongly recommended replacing the aluminum pan bolts. But that is a waste of money. The recommended torque spec is slightly more than finger tight.

 

Maybe a dumb question but does it matter if the diff fluid contains the friction modifier? I believe it is an open diff so it should not matter, correct?

 

Correct, straight gear oil here.

 

Hi Ryan,

While Jaguar and ZF marketed the transmission as "Sealed for Life" when new, ZF subsequently revised its service schedule and now states that the fluid should be changed every 50,000 to 75,000 miles or every 8 years at the latest.

There are only a few fluids approved for use in the ZF 6HP26, and Pentosin ATF 1 is not one of them. It's viscosity is much too high. ZF specifies its own Lifeguard 6 fluid, meeting Shell specification M1375.4. But through the research of forum members including Partick the Cat, Box, myself and others, along with a Blackstone Labs analysis by bimmerfest member fun2drive, we know that aside from color, Ford Motorcraft Mercon SP and Shell Spirax S4 ATF MSP are identical to Lifeguard 6. If you shop eBay, you can find a case of Motorcraft Mercon SP for around USD $140.00, or less than $12.00 per liter. Do not use any other brand of fluid claiming to meet the M1375.4 specification or to be equivalent to Lifeguard 6 or Mercon SP. This topic has been thoroughliy researched and discussed in thousands of posts, so please do not waste your time second-guessing this information.

If you have any leaks at the transmission, you do want to replace the electrical connector sleeve and the pan/filter assembly. The California Transmission Supply Company (thectsc.com) and FCP Euro (fcpeuro.com) are good sources for these parts. The odds are very high that you will strip the Torx head of at least one of the pan screws while trying to remove it, so it is prudent to have at least a few new screws on hand when you do the job. The new screws have a revised head and I seem to recall that they use a larger Torx bit, so they are less prone to stripping. If you shop around, a full set of new screws is not too expensive and will make your next service a little less nerve-wracking.

The procedure for refilling the transmission requires a precise measurement of transmission fluid temperature, so you need either a scan tool capable of reading all the Live Data PIDs, Jaguar-Land Rover Symptom Driven Diagnostics (SDD), a digital thermometer with a remote probe, or an infrared thermometer. If you use an infrared thermometer, point it at the fluid emerging from the transmission, not at the plastic pan, which is a poor conductor of heat and will give a false reading.

The choice of plastic or metal pan/filter is yours, but bear in mind that the Jaguar system was designed for the thermal characteristics of a plastic pan. If you use a metal pan, the gasket will eventually fail anyway.

The differential fluid is Ford WSL-M2C-192A, a synthetic 75W-140 hypoid gear oil. I typically use the Lucas synthetic version available at local auto parts stores, but Redline Oil, Mobil 1, Swepco, Amsoil and others make similar excellent products. I personally avoid the Royal Purple brand because I do not trust the claims of a company that feels it must use the terms "Royal" or "Purple" in its marketing.

The differential capacity is 1.25 liters / 1.32 U.S. quarts.

For more information on the transmission service, see these links and many others in the forums.

ZF 5HP / 6HP Transmission Fluid Fill Procedure

ZF 6HP26 / 28 Transmission Fluid Flush DIY

Cheers,

Don

 

Thank you for a very comprehensive and intelligent reply.

 

Thanks Don,

I've recorded this info, and have stored it with my service info,
Rob

 

After all those years yes do a pan, filter ,oil exchange on the tranny . Zf kit for 6hp26 is like 160€ . Plus the rubberparts behind the mechatronic( 4 tubes and bridgeseal) another 30€
just did mine on a 2003 xj8 211000miles that has had one at 80k and probably another one at 150k
I feel the difference .
On the differential suck the old oil out ,clean the screw put new oil in