Hi there,

Just about to do a trans oil change on my dad's xj8 (zf trans) the one that is "sealed for life". I reckon this should read " sealed for death"!

I was wondering, i see no references to multiple trans fluid changes to change out as much of the old oil as possible.

On my Saab, the dealer actually reccomended changing the fluid twice, to get out as much of the old oil as possible.

Seeing samples of the oil at each stage convinced me that this was a good idea. Also, driving it at each stage showed a progressive improvement in the shifting. It wasnt that it was bad to start with,it just got better at each change!

Anyone done this?

Thanks.

Mike.

 

Hi Mike,

I'm in agreement with you on the "sealed for life" thing. I respect the opinions of those who actually beleive that the trans is a "set it and forget it" from the factory. I respectfully disagree.

I have a 98 XJ8 and I thought I was looking at a trans overhaul until I dropped the pan and changed the fluid and filter. The trans., like the rest of the car, was raised from the dead. The noises and funny shifts went away. I am certain I gave myself thousands, if not 10's of thousands more miles by changing the restricted filter.

As far as the rest of the bad fluid, you can change it again and again. I've had a couple drinks but, I do remember a drain plug. The filter should be good after the first, service. Even better is a fluid exchange.

I have a machine at work that will exchange the fluid in the trans. You fill the new fluid tank in the machine with the total trans capacity + a couple quarts for insurance. You disconnect a trans cooler line and put the machine in series. One line from the machine to the disconnected cooler line and the other line from the machine to wherever you disconnected the cooler line. Start the car and push the exchange button. The trans pushes out the dirty/burnt fluid and the machine pushes an equal amount of new fluid till all of the new fluid is in the trans. I you run the trans in all the gears it increases the chance of purging as much old fluid as possible.

This seems like the best solutuion. The problem is the cost of the fluid and finding a shop that will do it for you. I used an aftermarket fluid. (another touchy subject) Most shops are afraid of the cost of the fluid and the true risk of pushing a marginal trans over the edge. Driving the car in and towing it out is never a good thing. I know the risk so I'm ok with it. It was a risk buying my Jag with a broken secondary timing chain. Owning a Jag will keep you rolling the dice. But, they sure are fun. Aren't they?

I expect see posts that will disagree with what I'm saying and that's ok. I think this is a great forum because of the diverse theories and opinions from so many knowlegeable Jaguar owners.

Regards,
Joe

 

i just purchased a 98 VDp with 130k. it is currently in the shop troubleshooting a possible bad rear wheel bearing that is making noise. the specialist in hawthorne nj who owns and solely runs the brit car shop was actually the one who worked on this particular vehicle in the past. anyhow long story short, i spoke to him at length about this subject after reading every relevant post in this forum , and in the end i have told him to drop the pan while its in the air. i will be supplying him with a new filter and gasket, and after reading all the arguements on fluid , have decided to go with the mobil 1 ATF. bottom line is you can get it at walmart, and it meets or exceeds all the specs of the original esso fluid, plus the price is right. you can check on the official mobil website. i will probably do another drain and fill sometime in spring when its not so damn cold to crawl on ones back on the driveway.
like you i also have a classic saab 900 which i did the 3 drain and fills on my manual gearbox with the german made GM fluid found on eeuroparts.com. the difference was absolutely noticable in shifting and feel, and i expect some positive result from the jag as well. good luck
i dont kow your milage, but anything approaching 100k i would be leary about doing the full flush as the gentlemen stated above. only for the reason that with the age of the unit there is the danger of dislodging contaminents and debris that have been there for a while and would only do more harm being loose. i agree the 2 drain and fills should suffice to get rid of almost all the original fluid , expecially with the capacity of these units.

 

I pretty much agree with you guys. I try to DIY all I can, and I didn't have a transfer machine, or feel like doing the cooler line thing, so I changed all the fluid I could and replaced the filter and gasket and cleaned the magnets. A couple of months later, I did a drain and refill. There is a drain plug on mine, the filter is pretty conventional. The only tricky part is warming it up and filling it while it is running. One of the exhaust pipes gets very close. I rigged up a hose and funnel so I could pour the fluid from the top and watch for it to over flow. I used Pentosin fluid which is another after market compatible fluid. I think it is a wise thing to do. Also, be gentle with the tranny when you start off especially when cold. I mean don't slap it in gear and hit the accelerater before it's fully seated in gear. My A drum is still okay and I plan to keep it that way. (I'm cheap !)

 

I am a bit wary about these flushing machines.

Transmissions are notoriously fickle, and contamination must be avoided wherever possible. It would be easy to let dirt into the system with a pressure flush device unless itwas kept spotlessly clean.