Any model crossovers for 4.2 liter transmissions ?
 

Need a trans and just want to see what if any other model transmissions can be used.

My car, 2006 XJR, 4.2 Supercharged of course.

Can a naturally aspired XJ trans work or does it need to be an R Type ?

Can an S-type trans work if its a 4.2 and or naturally aspired or does it need to be an R Type ?

I know maybe years will cross over (2004-2008) but I need to know If these models will. Cant trust the cross over list on eBay, at least I don't. Local AP dealer says an S-Type will work but I don't think so.

Thanks in advance.

The ZF trans in your car is a six speed. There are similar trans in the BMW X5. So I would start by checking the model number for your car and for each model you mentioned. I see that the ZF listing for Jags lists 6HP26, 6HP28, with the 28 having some type of thermostat. I think it is a 6HP26 in my 2006 XJR. Ask what the model number is on the tag on the transmissions that you are considering.

John, you need to find a donor trans from a supercharged Jaguar model.

On the tag you'll see a "SC" designation.

John,

Can you please tell us why you need a new transmission?

In our area, the Jaguar dealership and leading independent European shops have told four or five of my friends that their XJs and S-Types have needed either a new TCM or a new transmission, but in every case we have found that some combination of lesser measures has restored the transmissions to normal operation.

If you'll tell us the symptoms we may have some ideas.

Cheers,

Don

Its 6HP26...... but someone else has said it needs to be tagged SC. Thanks

Hi Don and appreciate the offer.

So last year I was finding an issue with it hunting for low gear after stopping at a stop light (Oct). Wasn't all the time but from time to time maybe once a month and I figured I needed to do the fluid and filter. Then late last year, in November it was either coming out of gear or searching for one when backing out of the garage so I parked it. I asked here and other Jaguar forums and was told its fluid and filter time hands down. I had an appointment with Jaguar to get it done plus reflash then had to cancel due to surgery in December. In January when I called them to rescheduled and they said they wont do it and refused to touch the car.

Also, I always have another car and its had maybe 100 miles put on it since November.

So after much research I opted to do the fluid and filter myself, along with the metatronic sleeve as it was leaking. I proceeded to do it all but did use Mercon SP as its all my local parts guy had 7 quarts of in stock. It is a direct crossover per his book and my research plus I needed to get it done for timings sake.

I followed the exact details highlighted in numerous posts and you tube videos. Finished it up and still had the issues plus pulled a code for the trans not finding reverse (can get the code number if needed).

So I again post here and elsewhere whats still happening and was advised to get it flashed/adaptations reset. I took it to my local Jaguar specialist (though I do not trust him) and was told he couldn't flash it, it needed a trans.

I then found another local guy who is a well know ZF trans guy, dropped it with him and he called a couple days later and said he could reset the adaptations as it needs a trans. Then offered to buy the car from me since it would be 4-6K for a new one which I found odd.

Anyway, the car is/was driveable after warmed up and in normal traffic. Can't floor it though as it will search for the downshift gear but driving it 1-5 miles in town its fine. Now here is the rub....... when I picked it up on the way home it now randomly falls out of gear, just rolling alone at 35 it will just fall out of gear and search for one engage and go. Sad that it got this bad not that I would have kept driving it. FYI, since the fluid change its been driven maybe 10 miles.

I hope this explains it well enough that you can get a proper idea of whats going on. If there are other options I am open to them. I am reasonably handy (cant own Jags without being) so provided I don't have to drop the trans I could try other things.

Thanks Don, appreciate it in advance.

You can look up suitable part numbers at jaguarclassicparts.com

My question was, what are the symptoms of malfunction that have prompted you to believe you need a new transmission? I've had several friends who were told they needed either a new transmission or Mechatronic/valve body, but they did not. If you're open to ideas, please let us know the symptoms.

Cheers,

Don

Put the car either on ramps or jack stands

I suggest that before replacing the trans, disconnect the battery and then disconnect the black cable connector that is plugged into the rear of the trans. Clean both the connector and the female connector mounted in the trans with contact cleaner. Reconnect the connector and then reconnect the battery. Do a test drive to see what is improved.

How many miles are on the car. If 100,000 or so, consider a fluid filter replacement.

Some of the issues you are describing were affecting my car and improved with a fluid and filter change.

Hi John,

Thank you for your thourough description and sorry I asked again for the symptoms but I think I was typing my last post at the same time you were posting your detailed explanation.

Based on your symptoms, I suspect two things are at play.

1. You do need to have the adaptations cleared, the firmware updated and then the adaptation drive procedure completed. The guy at the transmission shop probably knew that but may or may not have had the capability of doing it himself.

2. A very common problem on these transmissions is that the two screws that secure the gear selector cable to the left side of the gearbox loosen and sometimes even fall out. This causes problems selecting the correct gear or with the gearbox remaining in the proper gear. It's easy to check the screws from underneath the car. I'll add a photo or two from another computer in a few minutes.

Here's a shot of loose screws on an '06 I serviced recently - one screw was obviously going to fall out eventually but both were loose.


https://cimg0.ibsrv.net/gimg/www.jag...c8e97e1299.jpg

Remove one screw at a time, clean it, apply threadlocker and reinstall. Access is limited, and if you remove both screws at once it can be a real pain to get the bracket aligned and the first screw restarted.

https://cimg5.ibsrv.net/gimg/www.jag...117950fbe7.jpg


If the first two steps above make a positive difference, I would recommend you do 2 more fluid drains & fills or one true flush. Draining and filling only replaces about half the fluid, so you've still got about half of the old fluid with deteriorated slippage/friction characteristics that the Mechatronic could not fully adapt to.

Cheers,

Don

Thanks again Don and I saw you had asked the same question and was like, huh ? I thought I had explained it in detail.

I will check the linkage bolts plus when I changed the mechatronic sleeve I didn't use electrical connector cleaner which might be the code issue.

Also, I think I will buy the lifeguard and replace the fluid with that. I will have to check and see how to do a flush as you are correct there was only half the fluid removed so there is still half that older fluid in there.

Just need the time to do it now and hopefully a YouTube video on the flush procedure.

Thank you so much again. Updates to come !

No need to spend the extra $$ on Lifeguard 6 since we have confirmed that Ford Motorcraft Mercon SP is the identical fluid except for its red color. Our member Box tracked down the Mercon SP Material Safety Data Sheet from Shell Canada that proved that like Lifeguard 6, Mercon SP is made by Shell, and its base oils, physical properties, viscosities, etc. are identical to LG6. Ford dealers carry Mercon SP, of course, but also our local Advance Auto stores carry it for about $10.00 per liter. Don't use any of the "Mercon SP equivalents" from other brands, because their properties often vary significantly. Ford Motorcraft Mercon SP is the one.

Cheers,

Don

If you haven't changed your spark plugs and coils I would do it now. Faulty plugs and coils can cause that you described as or happened to me. It tends to behave better when the car warms up.

If problem persists next thing is to replace solenoids. They exhibit the same symptoms as well. They also behave better as the fluid warms up. When the fluid is cold the worn solenoids struggle whith the viscosity. If you're able to charge the tranny fluid you should be able to do this procedure. Make sure to change the bridge seal and tube seals while you're at it. I would replace electric seal again since it's cheap they tend to leak if they're messed with and you park on a steep incline.

There's a forum member in the XF section who documented solenoid replacement, he even went ahead and installed a ZIP kit as well.
I will hopefully be doing this procedure this summer as well.

Forgot to mention; don't rule out plugs and coils if you're not exhibiting misfire codes.
The jag is horrible at identifying these.