Thanks for the bulletins, but I have done much of this. I don't have IDS (but have SDD). I updated the calibration on the TCM yesterday, cleared the adaptations, and then used SDD to go through the adaptation learn procedure on the bulletin you sent me. Shifting is pretty nice, but still, have the occasional squawk from 3-4, and the surging - which is really the thing that's annoying me the most. Thanks again for all the comments - this forum is a great resource for anyone with an older jag.

 

It is possible the fluid is significantly hotter than the pan, since plastic is a poor conductor of heat. Try monitoring fluid temp in SDD or via Live Data on your scan tool, or, if you can get a line of sight on your fill hole, aim your infrared thermometer at the fluid dripping from the hole instead of the pan. If the fluid temperature exceeds 40°C by very much, your fluid level will be low.

Here's an illustration of the two types of bridge seals from a California Transmission Supply Co. document. It doesn't show part numbers, unfortunately, but you may be able to look those up at their website, thectsc.com (it appears to be down for maintenance over the holidays):



Cheers,

Don

 

Thanks Don,

It’s raining today so I will check the fluid level again when it’s dry using SDD. Hopefully that’s it. I think I have the right bridge seal. When I got it it had the wrong numbers on the molding and I thought they sent me the wrong one, but when I flipped it over it has the 6HP26 on there. The other side had 28/32 if I remember correctly.

will let you know how it goes. If it’s not the fluid I think it’s time to tear the valve body out on my own and see if the two places that worked on it for me did anything whacky. I hoped it would get to that but I’m running out of other good options.

John.

 

Just catching up but a rough 3-4 upshift issue, squalk, slip is pointing to your E clutch either starting to fail or really on its way out.

E clutch is the first to go. Main reasons, low or expensed fluid.

Might be worth hooking up SDD and monitoring pressures when you get to that 3-4 up shift. If you see the pressures not in the green zone - time to get her to a trans shop specializing in German transmissions.

 

Legit mongoose cable or clone? If the latter proceed with extreme caution... also V130 should have the TCM reflash calibration to remediate the "hunting" syndrome, which again should only last for your first 5 minutes of driving.

Should have zero hunting when car is fully warmed up but the latest TCM calibration file remediate that.

I have reflashed and updated TCM calibration and reset/adapted shift patterns. I have both IDS/SDD and a legit Rotunda VCM.

Again, be careful re-programming any module with a clone Mongoose cable or you run the risk of not successfully updating TCM or worse, bricking it - permanently...

Again, been there with the 3-4 up shift issue. More than likely E clutch and will only get worse with time.

 

Its a clone (but had no issues so far with it)

I plan to check the fluid at temp as measured by SDD as suggested by Don.

You mention checking the pressures with SDD. How do you do that. I have looked in the data logging but don't see any way to read the pressures (SDD 130) I do see signals for pressure regulator drivers (#1-6) which I assume are the solenoids in the mechatronic assembly - they are not green / red style, they measure the current in mA the is being supplied. I looked at those on a scan and don't really see anything jumping around at the time the surging is happening. Doesn't look there is a lot of data you can pull from the transmission? Am I looking in the wrong place? Thanks for the suggestions.

 

Checked out the fluid levels at temp measured with SDD. Reset the adaptations again and recalibrated via the drive cycle with SDD, I think it's a little better but still has some hunting. The next step will be dropping the valve body again when I get inclined to work on it again. If I figure out what it was I will post an update.

 

If you have a 3 - 4 slip or chirp odds are it's a mechanical failure. Dropping and replacing valve body will be no remedy

 

Hi abonano,

I am starting to think you are probably right - but continue to dig into this as it's odd most of this just showed up after a transmission service (for 3-4 hard shifts). The surging or chirps were not there before. It shifts very smoothly now, but these new issues appeared post fluid, filter, mechatronic seals, and solenoid changes. I messed a little with the fluid level the last couple of days as my driveway is not perfectly level (just to see if that had any effect). Don't really see much of a difference with about 500ml extra in there. I did reset the adaptations again and did a re-learn with the drive cycle and noticed something interesting.

The adaptation mBar settings seem to be negative for all the other gear shifts but 3->4 is positive. Is this normal (has anyone done this before and seen something similar)

Also is the SW version I have the one that has the fix for the surging when the tranny is cold - Z63K5660x350WW

Anyway thanks again if anyone has further thoughts.

 

I've never paid much attention to the millibar column - I've only been interested in getting all the green boxes checked. 300 millibars and -290 millibars are just over +/- 4 psi, so the pressure difference between the E clutch and the A clutch (the one with the greatest difference in pressure) is small, and possibly insignificant. But it is interesting that the clutch related to your rough gearshift is the one with the nonconforming pressure. I'll be curious to hear from any of our transmission experts.

Cheers,

Don

 

What fluid did you use to refill the trans? Was it Lifeguard6 or Mercon SP or another? If LG6 or Mercon SP the shift additive is in the fluid.

If any other fluid was used - you might be able to introduce a anti slip additive Jaguar introduced for the 3-4 chirp.

There was a TSB for it.

My 04 XJ8 had 3 - 4 upshift issues. Changed the fluid with LG6 and a chirp was apparent. After putting the additive in the chirp was less apparent but the E Clutch was pretty much shot.

Hope the above is helpful

 

Hi abonano,

Looking at the carfax I see the car was serviced throughout its life at the Jag dealer but there is nothing noted there that the trans fluid was replaced in its first 100K miles - so not sure if it was original until then. At 100K the prior owner changed the pan, and the mechatronic seal to the harness - I think he had a leak which could be the cause of a bad E-Clutch if the fluid got low.

At that time he put Valvoline MaxLife in it (red) or that's what the handwritten note he had on some paperwork I got would suggest - it has a red dye in it unlike the LG6 - he ran it with this about 2K miles when I bought the car and noted the 3-4 shift issue (sadly after buying it)

I had an independent guy do the fluid and filter again, change the mechatronics inside and the solenoids trying to fix the harsh shift. I gave him LG6 to put in so at that point it was probably a 50/50 mix of LG6 / MaxxLife as it was just a pan drop. The car ran like crap and the mechanic was clueless - so I took it to a transmission shop; who again were clueless as to what the problem was, they again dropped the pan and I pushed in more fresh LG6 - which would probably take me to around 75%LG6 / 25% MaxxLife right now assuming I get half out each time.

I have around 6L of LG6 left over that I could do one more change and further dilute the Maxxlife - it seemed to get a little better with each change - but maybe I'm just wishing that was the case. My only hope was MaxxLife was not an approved fluid and it is what's causing the slip.

What did you end up doing with yours - did you get the clutch replaced, rebuild the transmission, or source a new/used one?

Thanks for your time and thoughts

John

 

Hi John,

The MaxxLife is not specific for the 6HP26 trans. (Not looking to open up a Jag Forum debate on trans fluid... lol just stating my opinion)

I would do one more flush with LG6 and hope for the best...

As far as my 04 XJ8 - I traded it in for value towards my wife's truck. They gave me $5,500 value, couldn't complain. They only drove it around the lot.

Found the car for sale about 6 months later at a used car dealership for $6K. Just to be a dick I called and asked about the trans. The owner said no issues.

I promptly went there drove the car and 3-4 boom Trans Fault. Tried to get me to buy the car and after I stopped laughing told him to pull up the ownership info... couldn't resist...

Now I have a 04 XJR - bought it knowing it had a bad 1-2 upshift and hard bang into R. Drained fluid and it was over 2.5L low.

New pan, mechatronic seal, bridge and tube seals and a reflash, drive adaptions and she's as smooth as butter... and a plus it had a brand new factory replacement engine installed...

After my XJ8 ordeal I deserved a break...

 

Closing this one out. The car is running well now after a few flushes and just driving it. Gear shifts are smooth. I am left with the surging until the transmission has warmed up (5mins tops) and then no issues. Seems like this is a common issue on the 04. Spoke to a guy at Cars and Coffee last week who had exactly the same thing. Like many others, I'm going to enjoy the car as is and not chase this one anymore.

Thanks to everyone who gave me advice as I chased this down.