Everything was perfectly fine until I had my car major service, in which I changed all 6 Coil, Plug, Engine mounting, Gearbox/Transmission mounting, Engine oil & filter, Gearbox/Transmission oil & filter, Draining and refill the differential oil.

After major services, I started to encounter some issues in my car transmission. The gear shifting is not smooth and takes a jerk while shifting the gear. And sometimes I hear some sound as if something is wrong with the differential, but this sound comes only when I press the gas pedal. If the car is moving without pressing the gas pedal there is no sound of the differential. When the gear shifts down from 2nd gear to 1st gear, it takes jerk again.

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Jaguar XF 2011, 3.0 Petrol, V6

Thanks & Regards,
Hani Shakir
Dubai - United Arab Emirates

 

It could be that there was an incorrect amount of fluid put back into the transmission and diff; either over or under-filled.

 

Agreed. Check the oil levels again

Interestingly I tried to have the jag dealer do the transmission fluid change at my most recent service. 10 years and 60k miles. They suggested not. Said it's expensive, not needed and they have had far more issues with cars after changing than before.
Sounds like you need to take it back and have them check it all out...

 

In response to the dealer's statement rather than you, of course, but I've heard this line for years about automatic transmissions and I just don't buy it. ZF have even changed their official advice and said that sure, it's a "lifetime fill", but if you drive it hard you should change it every 50k miles, so I'm going with that option. I haven't seen any credible evidence to even suggest that it's "bad" in any way to change transmission fluids, despite how often I've read this.

That said - these 6HP28s are a pain in the *** to drain, fill, and get right. I screwed it up the first time even when on a lift and pretty confident the transmission is as level as possible. It's like they couldn't have made the job more difficult if they'd tried. Like really - you want us to drain, fill, and measure the level with one hole? You couldn't have put a separate fill hole somewhere else on the transmission? Really ZF?

Based on this, I'd say people can quite possibly see more problems after changing fluids, but this is almost certainly down to the refilling and level checking procedure.

 

See this post over on the Pommy XF forum: https://www.jaginfo.org/showthread.p...ht=power+flush
Yes, it's about an XJ and a diesel at that and the later ZF 8 speed trans but everything in that post also applies to the 6 speed ZF 6HP26 trans.
Bottom line - do not power flush these trans, just drain and refill.
Maybe the op's problem stems from a power flush?

 

This seems like sensible advice.

 

I literally work walking distance to Eriksson Industries in Old Saybrook CT. They are ZF factory approved re-builders, not a transmission shop. They provide rebuilt warranty units for ZF and manufacturers

Really nice guys. stopped in a chatted with them thinking about my car trans service (now with 92 K on it.)

They say ZF recommends service (just drain fill and filter) at 60K miles. He said manufacturers are the ones that say fill and forget. He does not do the work, they only do it for ZF and supply parts to transmissions shops so its not like they make any money telling me this. So to me its just advice.

The guy I talked to is going to ask the boss man about a local shop he trusts that I can take my car to.

 

I took back to the mechanic and he said fluid level is fine... There is no gage to check the transmission fluid level in XF 2011 model... please suggest if there is anomaly to check oil level in transmission.

 

From the horse's mouth,

https://aftermarket.zf.com/us/en/aft...on-oil-change/

https://aftermarket.zf.com/remotemed...fluid-8-it.pdf

 

Aside from links that @Jssaab has posted above - which are really important to follow as the level check procedure is pretty involved - also might be time to read the codes to see if anything's been logged.

 

Quoting DaveTibbs: In response to the dealer's statement rather than you, of course, but I've heard this line for years about automatic transmissions and I just don't buy it.
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Yes - I'd tend to agree with you. 60k miles feels like a plenty long life without a fluid change. And I don't believe just changing the fluid can cause issues. I was just surprised when I got the ZF statement saying 60k, showed my Jag dealer (who was quoting $1800 for the job) and he guided me not to do it. He was pretty adamant that they had seen more issues from touching it.

So I held off for now. I would diy it but seems much easier with a proper lift and the checking procedure is very involved...

 

Yeah I don't doubt they have. However, I don't think this is an inherent issue with draining and refilling the fluid, and certainly shouldn't be used as general advice to not change out any fluids - after all, if it was a bad idea to ever do it, why would it be both a ZF- and Jaguar-documented procedure?

I think the reason so many dealers, service techs, and apparently internet forum members have advised against transmission fluid changes over the years - particularly with the line that it "causes more issues" - is solely because with the 6HP26/8 transmissions that are pretty ubiquitous in our and so many other cars (eg BMWs) the level check and refilling procedure is (imho) quite difficult to get right and on our cars it's easy to burn yourself on exhausts while doing it. I had to recheck and add fluid at least twice in the days/week following the refill when I did it, and I assume the $1800 you were quoted is either to just dissuade you from having it done, or a reflection of how long they estimate it will take to do it right (though I imagine their markup on Lifeguard 6 contributes somewhat).

I get it - the fact that it's a mare of a job is a pretty good reason for a dealer to want to dissuade anyone from having it done, but I also can't believe that transmission oil is just fine to leave for (eg) 100k of hard driving, and neither (apparently) do ZF. Might be worth hunting around for an indy and get their take on it.

 

My Quote for an independent ZF certified garage (using all ZF parts and fluids) $525. Trying to decide if it's worth doing myself. Probably not...

 

I know I wouldn't attempt it without a proper hoist, one where you can get right under the car while still standing up.

 

I have access to a lift. won;t have a chance for a bit, so may not want to wait. Might just bite the bullet

Parts alone are 300, sounds like its a deal and I'll keep my hands clean

 

Yes - I agree davetibbs. I think there price was hefty for the fluid, but it does also take a lot of time given the complexity /fiddle of getting it right. If it gets too warm they have to let it cool and try all over again

I'm just surprised it has to be that hard!

Indy prices sound much more reasonable. I will prob do that after the winter