I have a 04 xj8, I am having the trans squelch during hard acceleration, the technical instruction for this known issue stated to flush the trans, changing the fluid that was put in by the factory with a different type. You said you ran that Mobil 1.
How well did it work? And Did you replace all the fluid with that type or what? Thanks.

 

The Jaguar dealer insists this is the proper way to do it and much simpler than the drain and fill method which DOES require a precise fluid temp measurement.

HOWEVER I have since decided to forego the fluid change after speaking with a transmission veteran who insists if nothing is wrong to begin with the risk of causing a problem does not justify replacing a fluid he believes is "lifetime" and a 23+ year Jaguar Master Tech who basically says the same thing, insisting the original fill ZF fluid will never wear out.

 

I thought the TSB said to drain and replace 1 quart of fluid with an additive?

 

It did. I have access to a flush machine, but no computer to determine the temperature of which the fluid needs to be. Is there a safe way to do this without knowing the temperature of the fluid in the transmission, or is it too important to overlook?

 

USMC,

Got to Harbor Freight or Northern Hydraulics Tools. Get a cheep Infrared Thermometer, less than $30 bucks and it will find many useful applications.

 

Great idea. Thanks. That would be very helpful.

 

Three years since this post, but have to say that the way original fluid looks after only 80k miles compared to fresh fluid makes me wonder this wear out thing more. In my opinion there is really no such fluid to hold its original chemistry for a life time and will wear losing its ability to do well its job over time and use. If ZF fluid is holding so specific chemistry over other brands it really makes no sense that over time and wear it still would be better than new fluid from other brand. Well, this debate and discussion will go on and on cause ZF as manufacturer will newer say that they fluid could be replaced with other brand.
My trans works better than ever so I guess that is what relly matter!

 

The easiest method to flush a good portion, if not all of the fluid from the torque converter, is while the pan is off, using a clear nylon hose the same size as the filter neck, place it inside the port that the filter tube goes into, and the other end in a gallon jug with 3~4 liters of fresh fluid, and start the vehicle with the pan off. Allow the pump to suck up the gallon or so of fluid as the old fluid comes out. This will not take long. Afterwards, simply button things up and do your fill.

 

"The easiest method to flush a good portion, if not all of the fluid from the torque converter, is while the pan is off, using a clear nylon hose the same size as the filter neck, place it inside the port that the filter tube goes into, and the other end in a gallon jug with 3~4 liters of fresh fluid, and start the vehicle with the pan off. Allow the pump to suck up the gallon or so of fluid as the old fluid comes out. This will not take long. Afterwards, simply button things up and do your fill."

I found David's idea quoted above after I did my flush yesterday on my 2005 XJR. In all of my research on this site about changing the transmission fluid it did not come up!!
Half of what I detail next is as most people seem to go thru in changing their old fluid. The latter half is not.


Anyway I had been meaning to change the fluid for a while and I finally bit the bullet yesterday after my case of 12 quarts of LifeGuard 6 arrived the other day. The pan/filter, torx bolts, and sleeve I bought 6 months ago.

I jacked the car up and leveled it off. I then sprayed all the torx bolts from the top with penetrating fluid and left over nite.

Next day the first thing I did based upon advice in this forum was to undo the fill plug. It took a bit of leverage using the correct sized allen key and I did whack my elbow when it released suddenly with a cracking noise. I thought I had broken something but all was well as the fill plug was nice and loose.

I had previously put down a tarp under the car to catch spills and used a big "bin" to catch fluid. When I took out the plug about a quart and a half came out. The transmission was at ambient temperature which was 28 C.

Next came the drain plug and after that the torx bolts, which were T40, all undid easily. About 4.5 quarts of fluid was collected and it looked really old. It was a very dark brown in color and looked nasty. The old pan magnets had a coating of very fine metal particles and the bottom of the pan had a coating of what I would call "sludge". So my thought was this beast was way overdue for a fluid change at 103,000 miles. My transmission however had been performing just fine.

Next I took the old sleeve out and put the new sleeve, lubed, in again based upon info in this forum. Putting in the new sleeve took me a while as I was reluctant to use force to push it home as I was not certain that it was aligned correctly. So I reconnected the wiring with its connector cap's lever tab facing down, the position of which I remembered, then pushed it in to position and then used a plastic pipe at the appropriate angle above the exhaust to tap it in. It did not require much force and went into position with the lock "brace" pushing back up and clicking into place.

Incidentally the old sleeve showed no signs of leaking.

I cleaned all surfaces and put on the new pan and torqued all bolts in sequence to the correct settings.

This is where I did things a little differently from others in this forum. I undid the clamp plate holding in the cooler lines to the side of the transmission and prized the lines out. I let them drain for an hour or so. I did not get much old fluid out.

I wanted to do a flush through the appropriate cooler line, which I have done on my Dakota with no problem. After pumping new fluid in through the filler hole until it dripped back out I asked my wife to start the engine. I wanted to see which hole it pumped out of to see which line to plug back in and which to use as the drain out.
Well after a pause of a second or maybe 2 seconds a huge blast of old fluid came out.
Not what I was expecting. Switched off engine and gave up trying to figure out which line to use. Instead I used a plastic bin cover as a deflector placed over the two holes in the transmission and deflecting down into my collection bin.

I then went thru a flush and fill procedure about a quart at a time with my wife's help.
About a quart would come out with the engine on for 2 seconds.

I ended up getting out just over 10.5 quarts of old fluid. Which is an estimate because of that initial blast of ejected old fluid which went everywhere but in the collection bin.
I filled up 10 quart bottles with old fluid so I know that for sure. I am guessing that a half quart was spilled.

Now here is the thing that worried me a bit. I only put in 10 quarts of new fluid. I did all of the procedures detailed elsewhere in this forum such as running through the gears several times and measuring the temperature of the final fill at 40 C when the fluid dribbles out. I used a remote infra red gun to do this and guessed it read a couple of degrees low. I did this twice after letting the transmission cool down because I had my doubts.

I know that I did not get out all of the old fluid however I believe I now have at most a new fluid fill with about at most a 5-7% contamination level with old fluid as opposed to about a 45-47% contamination level when you just do a drain and fill.

The car drives as it did before as I was not having any transmission problems however I feel a lot better.

 

That procedure you used will definitely change the fluid almost completely. But sounds very messy.
The fluid in mine at 99k did not look that bad. An overnight drain after removing pan collected 7 quarts somehow.
Plan is to just remove fill plug at 120k, catch overflow, then refill with engine running and run through the gears.
The six speeds are not as hard on fluids as the five speeds in the x308. The five speed ZF really has dirty fluid and sludge at 100K.
A new pan and filter is good for peace of mind. The transmission can go 300k if not abused.

 

If I had known how forceful the pump out thru the cooler line was beforehand I would not have had such a mess. With the deflector in place it all went down into the collection pan.

I sure hope I can go 300k with the transmission!

Maybe if the torque converter is in a particular position it will drain to some extent?

I have had the car just over a year and have put 5k on it since I bought it. I have upgraded a few things including the rear spoiler to differentiate it a bit but its the best car I have ever owned. I am retired so dont put a lot of mileage on it and do not drive in the snow.

 

I have a question for this thread - WHY?

All the experts say the box is sealed for life, and the fluids are designed for a lifetime's service. Why insist on changing it? Has anyones gearbox disintegrated because they didn't change the fluid?

My 2002 4.0L V8 XJ8 SE has done 240,000 miles and the gearbox has never been touched. It operates perfectly.

Incidentally, the pan is the shape it is for a reason - it collects any sluge (probably the result of condensation) and holds it. The sludge will stay there so don't disturb it.

 

Congrats on getting such a high mileage.

This topic has been discussed to death in several threads and the consensus is that "sealed for life" refers to the original purchase under warranty for approx 50k miles as such owners sell the car around that point.

I did not disturb the sludge, I removed the pan and filter and replaced both along with fresh Lifeguard 6.

Looking at my old fluid I would say that it could not be protecting moving parts nearly as well as clean new fluid period.

 

Ah ... ZF have changed their advice ... they now recommend changing the fluid at 50-to-80,000 miles (depending on severity of service) or at eight years, whichever comes up first.

Google on 'ZF 30094 EN' (comes up with PDF download).

 

By the way I was quoted $1300 for a simple empty the pan and a replacement pan/filter by my nearest Jag dealer. The service dept would/ could not give me a quote then and there but had to call me back hours later. With parts and 12 quarts of Lifeguard 6 my price was around $320. I got the Lifeguard 6 from CTFC on-line and after I ordered it they refunded part of the shipping charge. They did not have to as I would not have known but they did. Where do you get that sort of service these days?

My next project will be to replace all hoses including the "valley hose". About a year from now.

 

It's kind of nice when accumulated experience and common sense makes some of us old hands look smarter than we are.

 

Question David. With your method, the draw up of new fluid will be clean, however, with the pan off, where does the old fluid come out? Where should the drain pan be. My drain pan is large but still smaller than the transmission pan.

Also, if you have drawn in 3-4 liters, and don't shut off the engine in time, will you not begin sucking air and creating an aeration problem?

Apologies if the questions are remedial.

 

David's suggestion will work if you are very careful NOT to suck air.
Thats why I only ran the engine long enough to "exhale" about a quart at a time and then refill a quart until I flushed out just over 10 quarts.
As a follow up I checked the the fluid level after running the car about 30 miles with a couple WOT runs and at 40 degrees C +/- I needed to add a couple of fluid ozs.
The drain pan I used was an old cement mixing pan with ample coverage under the trans.

 

How did you get it that cheap? I'm at $295 plus shipping with only 7 quarts of fluid from them.

 

6 Speed Transmission Fluid

Have a look at the above link they quote $205.60 for a case of 12 x 1l plus shipping.

I paid the quoted shipping charge in the on-line order which turned out to be more than it should have been and they refunded me the difference without me asking.