ive had the fluid pan and fluid done on my 2003 x350 3litre petrol because I had the dreaded surging problem at around 30 mph. the transmission is now very smooth untill I get to 40 mph where the surging problem returns, the transmission was also re flashed when it was done, I have read that if the fluid change and reflash wont slove this problem then its almost certainly the torque converter that is at fault, the car has done 75000 miles.
has anyone come across this problem ?
2nd hand gearbox with converter is no problem to source but it might be just as bad and worn as mine , whats my best option here ?
recon box
recon torque converter
I am in Lincoln in the uk so would like to solve this issue as local as possible,

 

Recon torque converter and box if you need to replace both do the job once as you say you don't know what the secondhand one is like and if the secondhand one has a fault then the garage will charge twice if it's only the torque converter just have that replaced auto boxes usually last a lot longer than that mileage

 

yes I think your right about only doing the job once,
I hear so much about it just being the torque converter. the gamble is . do I just get that done or the box aswell

 

This 'hunting' syndrome is well-known and although a nuisance can be lived with. In my case, I noticed it shortly after purchase on my car in 2010 and 30k miles. Attempts to cure by re-flashing the TCM software don't seem to work, and anyway it disappears when the transmission fluid is warmed-up, which takes about 10 miles.


I have been told a change of torque converter cures it but nobody seems to be able to tell you why. So until I hear a rational explanation for this syndrome, I'm not going to do anything. My car is on 106k miles and it still 'hunts'.


What I do is put the transmission in '3' for a bit. This keeps the revs up and stops the hunting. Quite why Jaguar couldn't cure this at the time I shall never know, but then they failed to cure a lot of things. Maybe it's better under Tata Motors ?

 

the hunting on mine isn't that bad and if you feather the throttle as it wonders what gear to be in you can nearly make it take the next gear when it should,
its so annoying though as I love the car and plan on keeping it a while so would like to get it done.
trying to source a reconditioned torque converter in the uk is also not as easy as I thought it would be

 

FWIW, I was told by XJK Jaguar, who service my car, that the hunting is due to the TCM program switching the torque converter lock-up clutch on and off to generate friction and thus warm up the fluid quicker. The hunting syndrome was cured by reprofiing the friction surfaces in the torque converter so the slipping is no longer noticed. OK, that's what I have been told, and to be fair, their chief technician is an old Jaguar man. Only thing is it takes a lot of believing. but if a new, (and later), TC cures the problem it must be true.


However, I for one, am not going to spend a lot of money. I'll spend it when the TC packs up and not before. After all it is several hundred pounds to fix something that can be lived with by those enthusiastic enough to forgive their Jaguars a few foibles.