Hello folks,

I hope against hope that someone can help. About half a year ago the trans started accting funny.
Symptoms are:

- when going into D it engages very harshly. Into R it's OK.

- when you apply light throttle (i.e. try to maintain speed on the straight and level) it jerks, like power comes in pulses. About 3 per second. There is also a slight raise and dip in the rpms, but not noticeable on the rpm gauge. If I press the throttle more, it goes away. It's so annoying, because light throttle is how long journeys are undertaken.

- it absolutely refuses to change from 4th to 5th at WOT. Have to back down on the throttle, and then go past the shift point before I can press the pedal all the way again.

I'm at my wit's end, I did absolutely everything I could do:

- upgraded converter

- changed frictions to Exedy Stage 2

- new solenoids

- took the valve body apart, installed Sonnax's ZIP kit, and new separator plate

- of course, oil and filter were the first to be changed.

Nothing I changed made the gearbox perform worse, but not better either. It behaves exactly the same.

Does anybody else have these symptoms? I've sunk 3500 Euros in the gearbox already, and still it's not working as it should, almost as much as buying one from the dealer.

i ran out of options, does anybody have a clue?

Thanks in advance.

 

Have you updated the software in the TCU?
There are tech bulletins for the transmission with reflash provided?
it would also need to go through an adaption routine also I think.

Joe

 

Did you go to a Jaguar specialist before you spent a mint of money on the transmission ? Reason I ask is because reflashing the TCM software is normally the first thing one does to improve the transmission operation, before throwing money at it. You don't say where you live, so maybe you don't have a Jaguar shop near you.

There is a feature of the transmission called the "hunting syndrome". This occurs at light throttle whilst the transmission fluid warms up. Despite efforts by my local dealer, I still have this syndrome and just put up with it. For the first few miles it can be mitigated by running the transmission in "4" or "3", not forgetting to return to "D" when the car has run a few miles, to make sure you don't use too much fuel.

Can you explain what "Exedy Stage 2" and "Sonnaxes Zip Kit" are. ZF only recommend use of a single transmission fluid and other ones can cause trouble. This gearbox is used by other makes like Mercedes and BMW and is a reliable unit. However the controlling software is supplied by the maker working to ZF recommendations. It is very clear from what I have seen on this forum that Jaguar made a Pig's Ear of the software, although it may be correct now, hence reflashing with the latest version.

 

Zip Kit® - ZF6-6R60-ZIP - Sonnax

https://www.jaguarforums.com/forum/x...de-car-111127/

 

I come back to why the OP spent a shedload of money, but has not, apparently, read the fault codes. I think we all know there are issues with the TCM software, as do Jaguar.

 

The issue the OP is relating, does not involve any fault codes. The first place I would start is to disconnect the battery, do a re-span on the pedal, and then start it and let it warm up and then using SDD, go and do an adaption relearn.

 

Thanks for so many answers!
Of course, software and adaptation was done. Dealer says he has no idea, car has no codes.
Oil is the recommended one from zf.
Car does this all the time at speeds starting from around 50 km/h, not just when cold.
So I'm ready to give up, I just hope someone has heard about this...

 

There are certainly a number of variables involved, and dynamic adjustments by ECM/TCM can make it hard to diagnose. I'm certainly aware of the issue, and to date, through all the posts I can see, there are no clear cut resolutions.

Once you have lockup, if you run into fuel closed-loop lean rail misfire, or EGR application, it can be transmitted through the driveline, and may make you think you have a transmission problem, when in fact it is engine control. When you get really close to closed throttle, there are ECM routines that goes into a fuel cut-off, like deceleration. There are lots of variables. The trick is finding the root cause.

 

OP, where are you located ? You refered to Euros in your post, so somewhere in the European Union, I assume.

Much can depend on how the car was driven before you bought it. Could you tell us a bit more about the car, like how many owners, and how many miles/kilometres ?

 

Check ignition coil packs too. Had one case where various transmission faults were caused by two non standard coil packs. Apparently they were breaking down and messing up CAN communications. This was only found after a transmission rebuild.

 

I am in Romania, so yes, EU. Am fortunate to be a half hour drive from a dealer.
We had the car in the family for almost 10 years, bought it when it was 1 year old. Problems started about a year ago. Took it to another dealer in Bucharest, from May till December it sat there. They left it out in the sun the whole summer, every window shut, and my headliner was sagging. But that's when I first got the symptoms. They were barely perceptible.
In January I decided to rebuild the transmission, and also put some Exedy clutches. I also upgraded the TCC in the torque converter. After that, the symptoms got 10 times worse in intensity. Been like that ever since.

Oh, I forgot about another issue: when I change into 3rd or 4th at about half throttle or above, the rpms are a little higher (like 400rpms) for about a second, then they settle into gear. It's like it was slipping, like it woule have an intermediate gear.

It also flare-shifts some of the time... There are too many problems which are related to switching gears, it has to be the trans... right? Could tranny/engine mounts be the problem?

Where would I find a valve body for the S/C 4.2? Not rebuilt, just a second hand unit to see if that solves the problems. I don't want to buy a whole gearbox...

 

Hi Matei, I know Bucharest fairly well, having been there many times for work; we were assisting Ferovia Informatica with software.

As far as I know the same gearbox is used on all the X350s. I think you maybe need to find a ZF gearbox specialist in Bucharest. This box is used in Mercedes and other German cars, so there will likely be a workshop there somewhere although they will be fixing mainly German cars.

The valve block is replaceable, but a fault can occur whereby the sealing of the valve block to the rest of the box fails allowing fluid under pressure to pass into adjacent passages. Cure is to remove the valve block and reseal with a new gasket. I was told this at an automatic transmission shop near where I live, (I had my wife's VW New Beetle in for air con repairs).

So my message is all may not yet be lost !

 

I know the dealer in Bucharest, I've had great communication with the tech there, which is less to say for the rest of the staff... wanted to take a look at the (then) new F type, sales guy made an apology that he can't find the key, didn't even let me get into the car.

I live near the Western Border, my closest dealer is near Timisoara, which is half an hour drive on the highway from where I live.

Got a quote from the ZF guy who services Audis, BMWs, Ranges (all that use this trans), 1200Euros for a new valve body.

I have an appointment with the Jag dealer in Timisoara tomorrow, do another reset, and see how it goes. We'll also have to negotiate install costs for Andre's TS, so I might as well do the reset.

Considering the fact that the cost of a new VB is so high, if the reset doesn't work, I am considering searching for a valve body from another XJR... all I seem to find on ebay is whole gearboxes at 1500+... ebay uk has 6hp26s for 4.2 Xjs at 350-400, but none for XJRs. Should I wait? Is there another place in the EU where I could find the part or a whole gearbox at a decent price?

 

Sounds like a valve body issue. I had a similar issue with using the sonnax kit in the past. May want to try a rebuilt VB from a shop..Worth a shot at this point

 

Sure. Poland is the main source of used parts for all the Europe, Baltics, Russia etc. Also ebay.de can help very much with Jag parts.

Concerning your case I bet on SW. Find a good indie specialized on JLR. Dealers can do nothing with non-current lineup cars (sure there are some exceptions from the old guard, but very few these days)

Also check for voltage drops on all your ground points. At least check them for corrosion etc. Points can be found in Electrical Guide for your car.

I strongly recommend clear adaptations and reprogram TCM in person! If not yourself at least by indie standing after him. I had similar symptoms with car behavior being naïve came to dealer to clear the adaptations. They said they did. When I asked to re-flash TCM with updated firmware they said there were no updates for these cars ever. Curtain. Nothing changed after that visit to dealer. Nothing. I had to buy cloned mongoose, roll out SDD SW tool on virtual machine and do reflashing and clearing adaptations by myself. Result is night and day! All problems and jerks gone! Good luck on fixing your problems.

 

I'll note poland, although I don't know how to search parts beside ebay and .co.uk shops.

I can work with the Jag dealer, they are very open, and their labor rates are not that bad, at 28 Euros / hour. I phisically did the readaptations myself, with me driving on the highway, and the tech with the IDS laptop riding shotgun. Performed all shift points 3 times, till it was all green.

Right now I suspect other culprits as well, i.e. engine & transmission mounts, and / or the TPS sensor/pigtail - it's only at a certain % of TB opening that does all the funny stuff, may have a blank spot on there. When Andre's TS kit arrives, all mounts will be changed, perhaps also get a TPS and pigtail to see if that changes anything. And only if it doesn't work, go on from there.