Hi, I have 137k miles on my Jaguar 97 xj6 vdp. The fluid is slightly colored but not really. The car shifts as smooth as can be. From my experience with other vehicle manufacturers, changing out transmission fluid on high mileage vehicles usually tends to cause transmission issues with jerking and slipping within six months of replacement. Other people end up facing complete failures.


Is it safe to change out the transmission fluid on my vehicle or should I just keep it in there, even after it gets dirty?

 

My experience is that problems *rarely* occur.

I'd go ahead and change it, personally

Cheers
DD

 

+ HEAPS.

Change it out.

Simply drop the drain plug, let it drain overnight, IF YOU CAN, refill with the best fluid available in your market.

I use Synthetic Multi Vehicle Auto Transmission Fluid in ALL mine, and have done so for a good many years.

I, also, have heard of very few trans failures that can actually be traced to a fluid change. Those I have heard of, have had serious issues prior to any fluid changing took place.

None of mine have ever failed from fresh fluid, and some have SERIOUS kms on them.

 

Hi 97vandenplas,

I'm personally an advocate of replacing your transmission fluid periodically. It's not just "dirt" you have to worry about, but metal particles and the breakdown of the molecular structure of the fluid over time. I've never, ever had a problem after a transmission fluid change.

My recommendation would be to change your fluid and filter, but not before you've done your homework to know what type of fluid you should use. Modern fluids claim to be backward compatible, but their viscosity is often significantly lower than the original fluid specified for your car, and their friction modifiers are different.

For example, if your car has the ZF 4HP24 four-speed automatic gearbox, the original transmission fluid specified was probably Dexron III. According to Redline Oil, their D4 ATF is the fluid they recommend for vehicles for which Dexron II/III was originally specified. It has a viscosity index of 198. Their D6 ATF, which they recommend as the equivalent of Dexron VI, has a viscosity index of just 166. Yet despite this significant difference in viscosity index, Dexron VI is supposedly backward compatible for Dexron III applications. My belief is that this viscosity difference, along with possible differences in friction modifiers, may have something to do with the problems some owners experience after a fluid change.

Our '93 XJ40 has the same ZF 4HP24 transmission used in many X300s. The first time I changed the fluid using Redline D4, I was amazed at how much better the torque converter locked up. I hadn't realized how much it was slipping before. It's most noticeable in Sport mode and when downshifting for engine braking when descending a hill.

It is telling to note that ZF does not state that its latest transmission fluids, LifeGuard 5, 6 and 8, are backward compatible. Even more curious, for the older 4-speed gearboxes in our XJ40s and X300s, ZF still specifies Dexron III. They do not specify Dexron VI. To me, this strongly suggests that the gearbox manufacturer does not agree that newer fluids like Dexron VI will perform better, or even properly, in older equipment designed for Dexron III. See pages 2 and 3 of the document at the link below for ZF's recommendations for each gearbox range:

http://www.zf.com/na/content/media/u...omendation.pdf


It's important to remember that more than half of the fluid in the gearbox is retained in the torque converter and does not drain out when you remove the drain plug from the pan. Only about 4 quarts will drain from the pan, leaving another 4-5 quarts in the torque converter, so you have to do multiple fluid drain/refill cycles to replace most of the old fluid. Drain the pan, refill the system with fresh fluid and drive for 20 miles or so; repeat; drain the pan a third time, remove the pan and replace the filter, clean the pan and reinstall it with a new gasket and refill the fluid gradually until the fluid level after a long drive is exactly at the HOT line on the dip stick (if your car has one, if not, follow the workshop manual instructions). The level is important, and overfilling can cause problems just as underfilling can.

Other transmission fluids may be just as good as the Redline D4, but since a fellow XJ40 owner recommended it years ago it's the only fluid I've been willing to spend money on for our car. I'll be curious to hear from others. Here's the link:

Red Line Synthetic Oil - Automatic Transmission Fluids - D4 ATF


The transmission filter and pan gasket kits are inexpensive and commonly available from the good independent Jag specialists and even your local chain auto parts stores.

Cheers,

Don

 

+1 on changes

Ignore post immediately above, I think he's in the wrong section talking about "X's"
and rubber plugs under the battery tray.

 

I recently did a full flush @ 105K miles. I used the Amsoil pre-flush in it, took it to my local guys who charged me $30 to flush it with my Amsoil fluid. I've noticed it's much smoother, but still get a 3-4 shift vibration. When I disconnect the battery I always get perfect shifting. The trans module makes gradual changes that I don't like. Either that or the valve body has issues. The Amsoil made a nice difference and gives me piece of mind and I won't probably ever have to change again. I got the Amsoil, two cans of flush for $190 shipped.

 

________\
ok you are making a connection that seems to be there but isnt. It may be that you have a bad battery tray that has let up and is resting on the trans housing, or maybe that you have a just-right unbalanced wheel/tire that is vibrating at 3-4 gear, or even that you have a broken tooth in the transmission on the 3/4 set, but it cannot be that the battery disconnect is making it shift smoother, (are you taking the battery out after starting, and if so...??? In any case the overall point to takeaway is that any good synthetic oil approved or cross approved rather for mazda and vw will work in the 02-08 auto trans in the x type, period end of story, there is nothing magical about jaguar trans fluid. However while im here i will tell you that a british trained jag mechanic looked at me and said "you cant use anything but a jag alternator in the x type it wont work" and i said back to him " but its a nippondenso alternator, its from japan, you can just get it rebuilt for $150 if you are that paranoid about autozone, and my point is he believed this, so the legend runs deep. These are cars at the end of the day, and the x type doesnt even contain anything british made in any case, so point made?

 

hold on! FIrst Ive got my threads mixed up. Second, I want to take back what I just said. I once had a condition where believe it or not, the neg ground to the transmission was corroded, and sure enough, under the right conditions, the voltage to the solenoids would "flutter" and occasion a rough shift. If this IS the condition, simply supply the earth terminal with another ground to the suspect ground; an ammeter will not work, because of the voltages and amperages concerned. (that is it will show the ground is fine) (it can also be a bad connection between the aluminum and the copper, which creates a corrosion problem if the washer is bad; here clean the terminals and you should see improvement if cable is solid. Sorry!

 

Good to know! I have a California car but corrosion could be it. The tire balance isn't an issue and the 3-4 shift does create a shudder in the steering wheel. I swear resetting the battery helps. Doesn't the trans module "learn" your driving style and adapt accordingly?

 

Isn't the transmission filter a metal mesh and not a traditional paper media? I didn't do a filter change when I flushed. I have plenty of Amsoil left if I missed a step...

 

Don B is absolutely RIGHT and Complete on transmission advice and details. for Transmission Fluid, follow factory original specification. any other newer or synthetic ATF will not work well. Always replace Filter and rubber gasket when doing transmission fluid change. Viscosity of Fluid is the main issue and not the color/shade of ATF.

 

After reading Don's post more thoroughly I went to Amsoil's site and found that the Signature Series fluid I bought has a viscosity index of 165, while he says the ZF transmission is better suited for fluids with an index of 198 like the Redline. Perhaps I need to dump the Amsoil in this case and rock the Redline? The car is smoother with the Amsoil, however, didn't address the issues as aggressively as I would have hoped. Perhaps this could be why? My car has only 103K miles and want to get the most life I can out of this "kitty car" as my daughter calls it.

 

Ive had issues with a trans fluid change on cars over the years, but 137k is not imo that high. And really should not be a issue on that trans either. But that said i would never recommend a complete flush.ever! Only a drop and fill every 60k sooner if towing, off roading, driving hard regularly(you know who you are) these are the things i do on all my vehicles, cars and trucks. So you would be ready for your 3rd. I just did a drop and fill on my 04 i bought with a little over a 100k and i know it was never done before cause the previous owner only fixed what broke not maintneance other than oil

 

Brutal,

If you're only doing a drop-and-fill, are you careful to only use Jaguar (or ZF) fluid, or are you not concerned about mixing fluids? I've read some concerns about fluids from different manufacturers not mixing well.

Thanks in advance for any additional details.

Cheers,

Don