Hi, I have a 2009 2.7 XF. When i use the paddles sometimes (in D or S) it feels like the clutch is slipping, obviously being an auto this isn’t the case, but something doesn’t feel quite right. It tends to happen more when you put your foot down, the engine temp doesn’t seam to affect it, thinking maybe it’s the oil in the gearbox needing to warm up? The car doesn’t feel like you've just changed up a gear, it just moves the rev needle a few hundred revs and keeps revving, but you cant feel it "throw you back so to speak", where as when it does it properly the needle drops a considerable amount more and the car puts you in the back of your seat and feels like it has changed gear properly. Another thing to note is if this slipping happens, I let of the throttle momentarily and it "engages" and pulls away as it should when you put your foot down. Has anyone else had this problem? Sorry if this is posted elsewhere on the site!

Cheers,

Bob

 

Sounds like your transmission is slipping. Try a fluid change, that may solve the problem. How many miles are on the car? Don't let someone tell you that the transmission fluid is "lifetime".

It may be related to the fluid warming up, but unlikely based on your description.

 

Thanks, I did wonder this. But indeed someone did tell me it's a sealed unit so I dismissed that. Where is the fluid top up etc? It's done quite high mileage 140K. What spec oil do they take?

Cheers,

 

It is a sealed unit. Unless it is in severe service (lots of towing for example) ZF doesn't recommend a fluid change. There is no top up or drain facility, I believe the fluid change is done through the cooling circuit hoses but I am unsure about that.

As for service life with no fluid change bear in mind that ZF does know a thing or two about their own transmissions. Modern lockup transmissions do not heat the transmission fluid as much as older designs did because the torque converter is hardly in use at all.

The mechatronic control unit is a more likely source of your difficulty. Any ZF approved service facility should be able to read the mechatronic control unit and re-flash the software.

Finally, the transmission control unit is adaptive and alters shift character to match what it "learns" is your driving style.

Try a stint or two of very aggressive driving utilizing the paddles in Sport mode and see if the problem resolves itself. If not then get the tranny brains read.

 

Hi, thank you for that. It hasn’t got a tow bar on the car (not to say one hasn’t been removed before I got it, but I think it was more of a reps car accounting for the high mileage, the previous owners address was Glasgow and the service history was all at Fox's Cheltenham. Thinking about it, when you do drive it aggressively it does do as it should, its only if you knock it down to overtake someone and then come back up through the gears that it seams to play up. I will see if I can find a ZF specialist and if I can get it plugged in then that will give me peace of mind. Thanks for your help.

 

I have had several Audi's with ZF transmissions and there is a method to change the fluid. The Audi dealer charged me about $300 to change the fluid with the "approved" (and expensive) replacement fluid. At first the dealer gave me the old line about the fluid being "lifetime", but they agreed eventually. I felt that the cost of this is far lower than the cost of replacing the transmission at a cost of between $8,000 and $10,000.

Yes, the Audi is all wheel drive, but it uses a very similar transmission. If I find the information from ZF concerning this, I'll pass it along. Some independent shops might offer this service, if the dealer does not.

 

Update. Have the dealer determine if the car has thrown any "codes" regarding the transmission and have those addressed first. According to what I can find out, these transmissions hold about 10 liters of transmission fluid (ZF LifeGuard 6 or a Jag approved fluid) and only 5 can be drained. The filter also should be changed.

Also check to see if there are any TSB's on the issue (I believe there are for BMW's Jag's and Audi's). If there are, the dealer should address them based on your description of the problem, and that may include a re flash of the TCU and a fluid change. I'll see if I can locate that document.

 

Well, this discussion has been had elsewhere, so here is the link. Make up your mind based on these additional comments (this may just "contaminate" the issue). There is a PDF in one of the posts from ZF.

https://www.jaguarforums.com/forum/x...ossible-65598/

Good luck