The transmission in my x305 V12 has developed some problems.
Recently I ocasionally heard a bit of a “gurgling” sound from the gearbox. I thought the oil might be low, checked and indeed it was a tiny bit low. I added about 200ml of ATF. After that it was a bit high but nothing changed. The noise has since grown to kind of a rattling, rumbling and gurgling. Happens occasionally and most often when the gearbox is still cold. It also sometimes goes into limp home mode, wich resets itself when the car is restarted. I checked the oil again and found this:
It was nice and red about 3000km ago. Then the noises started. It got a bit darker, but it looks a lot worse in the picture than it actually is. My concern are the grey streaks, they are fine metal particles.
Are these transmissions know for failing in oil pumps?
That’s what it sounds like to me. Very similar to a failing power steering pump.
Oh well. I will put the car on storage for a while anyway now. And I always wanted a manual V12. So maybe…
The 4l80e is certainly not know for weakness, being used in monster torque turbocharged Bentleys. The good news is that it is a common transmission, so unless you really want to go manual, you have plenty of 2nd hand units. In my opinion unless you have a trusted specialist nearby, better get a good second hand unit with warranty.
Yes, I know that
I ment to ask, how long do they usually last? Is 285000km about the life expectancy of of such a transmission?
Also, I am always curious and would like to know why it failed and if that is a common cause of failure.
Mine lasted around 350,000 kms before it needed a completed rebuild. The fluid looked good right up to the rebuild which was brought on by slowly degrading performance over many years caused by wear in the valve body. If I had replaced the valve body when the problem first occurred then the rebuild might not have been needed.
The 4L80E is a GM transmission in a Jaguar case and parts and service should be readily available.
Since you are in Germany, and local experts are probably few and far between, you should consider rebuilding it yourself. I’ve only rebuilt the TH 400, but a 4L80E despite having four speeds, is pretty similar, and even has some interchangeable parts. If you are brave, it is totally doable to rebuild this yourself because there are some excellent books available. Look for 4L80E transmissions by.Erik McClellan. It’s a full color bolt by bolt instruction manual. Do not be tempted to modify the transmission just do a straight up clean rebuild.
As for the reason of failure, simple wear, and you do have a lot of miles, or old age that makes rubber seals very very hard, or where, in the pump that reduces the pressure, or literally something just broke. After this many years, it owes you nothing.
I bought the car with 249000km on the clock. It’s been driven hard (as you have seen in the V12 thread. That was actually after the noise started, when it does not go into limp mode, it still runs and shifts fine).
Thanks for your input!
No, it doesn’t owe me anything.
I sold the family car in August last year and will have the new one by the end of this month. I had three pleasure to drive the Jaguars as daily Denver’s since August. The 3.2l manual from August till October and the 6.0l from November until the end of this week. I have had the V12 since 2012 and replaced it with the 3.2 in 2017 when a lorry crashed into it. A friend of mine bought it, fixed it but didn’t drive it a lot. When he didn’t want it anymore I got it back. I was driven 500km from 2018 to 2022. Then I have put 8000km on it in the last 5 month.
Furhter to my earlier post, when my transmission problem was getting worse I just took the car to a local transmission workshop that I had used previously and the tech knew exactly what was wrong when I described the symptoms.The workshop I used was not Jag or GM specific but it was obvious that the tech had a lot of experience with all sorts of transmissions.
My rebuilt transmission has performed flawlessly for over a year now.