Intermittent gear change clunk at lower speeds

[RodFerris]

Hi, Car is 2005 X350 3 litre XJ6 with 75K miles. Bought the car in October 2022.
The car is suffering an intermittent harsh gear change clunk accelerating at low speeds. It is almost as if the gearbox cannot make up its mind as which gear it should be in.(if that makes any sense). It doesn't happen all the time but i noticed on a run through town today it happened 2 or 3 times in slow moving traffic. There are no fault messages showing on the dash. The gearbox was last serviced in 2019 By Arun independent on 66K miles. The last work carried out on the car by the previous owner was in 2020 when the ECU was replaced due to a non starting issue.
I had no problems during the test drive or over the last couple of hundred miles. I admit I have not used the car that often as my wife prefers the comfortable seats in our old X308 se which the X350 was supposed to replace but which i am reluctant to let go now.
If anybody can give me an ideal of whats going wrong before i book it in for a potentially expensive repair, i would be very grateful.
Thank you
Rod

[andypryce]

The normal response to these sort of issues at that mileage is 'change the gearbox oil' as the first step, but presume that was done in 2019? I would still definitely get the oil level checked and maybe change it again, that may cost a couple of hundred but hopefully may sort it.

[PaulGover]

Have you disconnected the battery recently? The gearbox loses its adjustments memory and it can take around 50 miles to relearn the settings. The handbook talks in terms of driving style, but I suspect it's more to do with allowing for wear on the clutches and brake bands.

[RodFerris]

Thank you Andy and Paul for your replies, I think i will book it into one of the nearest Independents to me, either Swindon or Swallows and get the gearbox oil levels checked and a diagnostic check.
I have not personally disconnected the battery in my ownership as i haven't got the code in my file for the centre information console (radio, sat nav and climate control etc). I would assume the car would have learned my driving information on the drive home from collecting the car. (100 + miles) and i have not touched the car since) There was a new battery fitted prior to my purchase of the car.
I was given a 12 month Autoguard warranty when i purchased the car, so maybe that will soften the blow in worse case scenario and hope that either Swallows or Mike Allen services are participating garages. I'm aware these warranties come with a lot of restrictions so i won't be holding my breath.
Not a happy bunny with this car!
Thanks again for replies.
Rod

[andypryce]

Keep us posted. If the car has been sat for a while then just possibly it might resolve itself with use, or maybe I am just being optimistic….

[RodFerris]

Hi again, just been out for a drive to try and get a clearer picture of where the thump into gear is taking place. It is almost certainly between 2nd and third change up when driving in slow moving traffic. If driving positively and normal it changes up as it should, without any thumps. When it thumped into gear the last time, an error message came up "Gearbox Fault" so i plugged the Icarsoft 90 in and the fault code "shift load 2 - 3" came up confirming my previous statement between 2nd and third gear.
Reading my Autoguard warranty, It does cover Automatic gearbox but has a repair limit of £1000 and its not clear yet as to who they authorise to do the repairs.
Will ring Swallows on Monday and seek a bit of advice as to next move.So back into the trusty old (and rusty)X308 for trip to Bristol to see the grand kids. Least the wife will be happy and comfortable, so not all doom and gloom.
Will continue to update on progress.
Rod

[andypryce]

Thanks for update, no idea what that code means!

[RodFerris]

Hi Andy , Code was "P0782 2-3 shift/Gear load 2-3" to be accurate.
Regards
Rod

[andypryce]

Thanks though none the wiser! There are some clever bods on here, hopefully they will cast some light…

[RodFerris]

Hi,
Contacted the warranty company and got the go ahead to get a transmission diagnostic, so booked in with Auto Transmissions Gloucester on Monday 3rd April. I fear a sleepless week ahead.
Rod

[andypryce]

Nah, remember it’s just a car!

[RodFerris]

Yeah, You are absolutely right.

[RodFerris]

Hi Again,
Just an update after car has been into Transmission garage for diagnostic. it doesn't sound good. I had a call back from the receptionist who said that the box requires a rebuild. She quoted £3210.00 for the work to be done. Does that sound like a fair quote anybody? Or should i shop about a bit more? I haven't spoken to the owner regarding how bad it is but will do that tomorrow after a night to digest things. I have to admit i Didn't expect this problem as i spent some time looking for a good low milage X350 with all the evidence of problem issues sorted to replace our X308.
Rod

[davidr]

Hi Rod - that sounds like a lot of money to me!
If it were me (and of course it's your choice!) I would be sourcing a used gearbox from one of the breakers that advertise in the magazine such as Autoreserve or Eurojag and then put the car in the hands of one of the many excellent independent Jaguar garages to fit. My guess is that the cost would be about a third or less of what you have been quoted.

[andypryce]

Quite agree, you can get a used box from one of those suppliers for a lot less than that. Was it a jaguar independent you took it to? Where are you located? When I had a gearbox fault the local transmission specialist didn’t have a clue to be honest, local independent Jaguar guy was much more useful, turned out to be the rotary switch and nothing wrong with the box at all.