I have a 2004 XJ8 that had been experiencing a pretty harsh shift from 3rd to 4th. I haven't owned the car long but the previous owner said they had the transmission serviced last year. Looking at the documentation I got with the car it looked like they had done the pan/ filter and replaced the fluid with a compatible brand (not ZF)

Having read much of the transmission topics on the forum and on Youtube, I elected to just bite the bullet and have the transmission serviced again. I replaced the seals on the valve body, mechatronic seal, pan & fluid and all the shift solenoids . All the replacement parts are new original ZF parts including the ZF6 fluid. After the service, the car is now shifting a lot smoother. 3-4 is still not as smooth as others but a huge improvement - before it clunked but I don't get that now.

While the shifting has improved I have unfortunately encountered a new issue. When I am cruising without my foot on the gas (say down a hill) the tach surges back and forth by around 250 rpm from the steady state rpm and the car feels like it's cycling back and forth between light braking and acelleration. I have a mongoose cable and reset the adaptations hoping this would help. No joy.

The guy who did the work claimed he checked the fluid level at the correct temp (I thought maybe it was low and pressure was building and dropping). For now I will take him at his word, but will probably check this next.

Any ideas about what could be going on?

Thanks in advance for any suggestions.

 

I have 2003 xj8 347000km 217k miles first tranny service at 125k km than probably 300k and last one with mechatronic sleeves, bridge seal pan filter with lifeguard 6 plus engine 2 mounts and the engine transmission mount. No solenoids
Good now but 4-5 sometimes not as smooth as the rest of them. I guess the solenoids would give another improvement but have hey it seems like the cluthes would need to be changed and that woul mean complete overhaul at a specialist .
when the engine transmission mount is letting loose the transmission body might slide forward or backward a liitle more depending on uphill to downhill driving , getting some sort of clunk too

 

Thanks for the input. I will check the mount but I don't suspect it. The issue I am seeing is not a single jerk when going downhill (as I would expect if the transmission mount was worn) the car motion oscillates slightly as the RPMs flutter by around 250rpm back and forth.

 

Known issue with 2004. The lock-up torque converter is engaging/disengaging/engaging/disengaging.

The first X350 I drove a couple of years ago when looking to get on was a 2004 and it did this, which was a dealbreaker.

Here's another thread on it: https://www.jaguarforums.com/forum/x...verter-137033/

 

Thanks for the info. Has anyone done the ECU reprogram on their own? I have access to SSD and a mongoose cable (which I used to reset the adaptations). If there is a write-up on the procedure to do this I may give it a try to see if it fixes the problem. Also, does this typically go away when the trans is warm (mine doesn't) some of the comments in the thread wfooshee highlighted seem to suggest this stops when warm.

Again thanks for the thoughts and help.

 

Most likely a torque converter issue. Whether its the converter itself or the lock up solenoid is hard to say. I'm no expert on the ZF trans, but this is pretty common in a lot of auto boxes with lock up converters.

Any good transmission shop with a proper scan tool can tell you what is going on with their equipment hooked up and taking the car for a drive. It will show converter slip (if any) and they can usually tell what's causing the slip. Good luck, hope it works out OK.

 

if new tcc control solenoid doesn’t fix the problem you need a new tcc it’s that simple

i bought a valve body for a ford 5r110 that literally had a bad tcc solenoid out of the box

 

I replaced all the solenoids as part of the service as I had a rough 3-4 shift. I guess I could have been unlucky and got a bad one, but I bought genuine ZF parts to try and avoid cheap knock offs given the cost of the fluid $$$$. I had hoped to replace all easy stuff in the hope of taking care of the issues. The surging wasn’t there until after I did the service.

you mention replacing the TCC is that the electronic module in the transmission the solenoids attach too or is it part of the valve body?

Thanks.

 

Is the surging all the time, or only in the first 10 or so miles of driving from cold ? Early cars suffered from what I call "hunting" when on a low throttle. Revs would vary like yours around 200-250 revs. This disappeared when the transmission fluid was warmed up. I was told by a Jaguar technician it was a rather poor attempt by Jaguar to warm the fluid up quickly, by operating then releasing the torque converter lock-up to generate friction. Seems a totally barmy thing, and my second X350 (a 358) didn't have the problem so Jaguar sorted it out. My first X350 was a 2003, and I also had rough changes and a few other issues that were eventually resolved with a TCM reflash with later software. This was done at Royles of Wilmslow who are no longer trading. Jaguar, in their bovine stupidity phase, (still ongoing !!), took the dealership off them because they weren't prepared to invest huge amounts of money. Yet they were a very successful dealership sited within probably the richest area outside Manchester. Total stupidity !!

 

Seems to do it all the time. Even after the transmission has warmed up. I may take it on a longer run tonight to verify.

I may try the reflash, but not sure of the process in SDD. I checked the campaigns and I see an ECM and TCM update. Got to the part where it said do I want to load new calibrations; but I chickened out. Don’t want to brick it until I know reflash is the only option and hopefully have someone who has done it tell me I am on the right path. I have SDD V130.

Thanks everyone. The community here is amazing.

 

Hi withersjw,

It seems unlikely that your torque converter would suddenly fail after a transmission service. It seems more likely that something went wrong during the service. Perhaps the fluid level is incorrect. Or perhaps one of the Mechatronic seals did not seat properly (did you replace the large rectangular bridge seal and the small tubular seals?).

Have you scanned for diagnostic trouble codes to see if any transmission- or network-related codes are stored?

It would be worth confirming the fluid level again at the correct temperature as measured via SDD, and not via an infrared thermometer aimed at the plastic pan, which will give an inaccurate reading. If an infrared thermometer must be used, aim it at the fluid emerging from the fill hole.

It is easy to get the fluid level low by allowing the transmission fluid to get too hot during the fill procedure.

I am attaching a document from ZF with the correct fluid level setting procedure.

You are right to be afraid to carry out the firmware update, but it can be done with SDD and a Mongoose cable. There are precautions you must take, such as having a low-ripple 50-amp power supply connected to the battery and your laptop plugged in via it's AC power supply and not running on its battery. However, updating the firmware will not solve your surging problem. Solve that first, then consider doing the update after you do your homework on how to do it without bricking your Mechatronic.

Cheers,

Don

 

Thank you

Yes I bought the bridge seal, and the 4 valve body seals and provided them to the mechanic along with the seal for the harness. The guy told me he used a scanner to check the temp when he filled it with ZF6.

I will try to check the fluid level myself.

I also confirmed last night that it is doing this even after the car is warmed up.


Thanks for the advice.

john.

 

hello. Im having same issue with 2001XJ8
Did you recheck fluid?
did you isolate issue yet?
Thanks

 

I haven’t had a chance to check the fluid level due to travel. Will try and get to it this week and post an update.

 

Well got around to checking the fluid level. It seemed fine so I decided to put it into a local transmission specialist to see if they can figure out what is happening. I will post the outcome when I learn more. Thanks for everyone's input.

 

Hopefully an easy, inexpensive repair, good luck

 

Still no major breakthrough. The transmission shop was clueless, they drained the transmission and refilled it and claimed they couldn't really see anything wrong, and recommended a new transmission. So back at it myself. Given there wasn't much to lose, I checked the fluid level again - seems fine. I bit the bullet and did an update to the ECM and TCM from SDD 130, reset the adaptations, and did the SSD adaptation drive cycle to learn them. It's better but still not great. I have the occasional creak from 3-4 (shifts are not hard) and the hunting/surging is still there.

At this point, the next step is to probably pull the pan off and check the mechatronic seals are seated correctly, check the new solenoids are the correct impedance, and that the new ones were not damaged in the installation. It's very frustrating that you pay people and then need to do the work again yourself because you don't trust their ability to get to the bottom of this.

Thanks again for the suggestions.

John.

 

Hi John,

Thanks for the update. Sorry you're still having issues. When you have checked the fluid level, you've reported that it "seems fine." Are you checking the level with the car as close to level as you can get it on jack stands and the transmission fluid at exactly 40°C (not measured at the plastic pan)?

It would definitely be worth checking the Mechatronic seals. Also check to be sure the bridge seal is the correct type. There is a different type for the 6HP19 that is the incorrect height and suppliers have been known to mix them up.

Cheers,

Don

 

Hi Don,

Yes the car was level on ramps. I did the D/R for 3 seconds to get the fluid in the TC. Then checked the fluid at 32-35C (IR thermometer on the plastic pan - I read it’s within a degree or two of reading it with SDD). Had a little dribble coming out at this temp and capped it.

The square seal I had had was part of a kit. Here were the p/n. This OEM Kit Contains:

• Part # 24 10 7 519 314 SEALING ADAPTER, QUANTITY 2 OEM ZF
• Part # 24 10 7 519 315 SEALING ADAPTER, QUANTITY 1 OEM ZF
• Part # 24 10 7 520 715 SEALING ADAPTER, QUANTITY 1 OEM ZF
• Part # 24 34 7 588 727 ADAPTER SEAL PLUG, QUANTITY 1 OEM ZF

Thanks for the suggestions.

john

 

TSB and DTC guide.