From what I've read in previous posts you can get rid of the surging / hunting issue with the TCC during the warmup cycle by updating the TCM and ECU software to the latest version and replacing the torque converter with a redesigned unit. Where can I buy that new torque converter? I'll take the car into the dealer for a software update but I want to replace the converter myself and I don't feel like paying dealer prices for the new design. Is it identical to units used on various BMW cars or is the converter unique to the Jaguar?

 

PCM/TCM re-flash (around $150 to $200 - needs to be done at the dealer or by a shop having a dealer level scanner.

Regarding the TC- if a shop does it your looking at around $2K

At 117K miles I would first try a fluid, pan and electrical sleeve change with clearing adaptions and a PCM/TCM re-flash.

This may be enough to make the trans behave more appropriately.

Final word of advice - use Lifeguard 6 (OEM spec fluid)

Hope this helps..

Oh, check your trans lines for weeping/leaking (super common fault)

 

Shop won't be performing the work, I do everything myself. I have an opportunity to buy a used 2005 trans with the TC at 85k miles for 400 bucks... I'm trying to decide if I should go for it. If nothing else it would offer some spare hard parts for any future issues.

I mentioned taking the car to the Jag dealer for programming because I'd rather place the risk of messing up the ECU / TCM on the dealer vs. me. For a couple hundred bucks it offers me some peace of mind that if anything happens it will be sorted out.

My understanding was that there is an updated design for the TCC that holds firm during that warmup cycle. If I don't buy the used transmission I'd like to buy the brand new torque converter and install it myself at the same time that I change the fluid / filter.

Which electrical sleeve are you referring to?

 

He is referring to this sleeve here.

Just did the exact job in question. Pan, sleeve, fluid (zf6), TCM flash. Costs to me are about 500$.

This site is the cheapest on fluid

Mechatronic sealing sleeve

 

Just to let y'all know that when I bought my car in Spring 2010, I soon noticed the hunting syndrome. It is still there despite two reflashes of the TCM but no worse than it was in 2010. Car was on 30k miles in 2010 and is now on 90k miles, so unless something lets go, I'm leaving it alone. It disappears when the tranny fluid warms up anyway. Of course now it's winter, the engine and transmission takes longer to warm through, so I notice it more.

 

Well that's why I just want to replace the stupid torque converter. Someone mentioned in a prior thread that there is a new design out there with a redesigned clutch. I just need to know where I can buy it. The 6HP26 is used in all sorts of cars... is the torque converter the same or is it tailored to mate up with the specific engine. In other words does each MFR design the flex plate to mate with a standard ZF torque converter or does ZF design the torque converter to mate with each engine.

 

I had a surging problem after changing the trans fluid, and I started looking for a torque converter. You can check this out: Untitled Document
This source is used by trans shops, I understand.

It turned out to be that I had messed up the viscosity (thanks to Don's advice!), so a complete flush and refill with ZF fluid took away the surging problem.

 

So your original flush was with something other than ZF brand?

 

First time I didn't flush, just drained and refilled with Mobil 1, which I had read on this forum could be substituted. Much much cheaper. I also used a quart of Lucas trans additive because of the age and high mileage of the car. So whether the viscosity got polluted by the Mobil 1 or the Lucas additive or both, combined with the leftover ZF fluid, I'm not sure.

 

After commuting with the car continuously for a week now I can see that it is very consistent. It basically does the surging thing until the whole mess reaches normal operating temp and then the surging disappears. I'll proceed with a fluid change, filter and sleeve change and see what happens.

 

Just wanted to say thanks to Fraser. You may have saved me quite a lot of money. My 03 x350 has been surging on warm up for a few weeks and I was all set to search out a torque conv. I am truly smitten with my car, its the best XJ I have had and my car only does it for a short time so can live with it.

Thanks again Phil