G/box: 4T65AWD: 2004 T6 Transmission - Bit of advice really

[poisondart]

Hi,

Bought a 2004 T6 Exec with 97k on the clock, with full Volvo service history a couple of months ago. Very nice motor; was only after coming on here I learned that the T6 has some transmission issues!

Well to be true to the T6, a couple of weeks ago I noticed that it was struggling to find 4th gear; it was revving up to over 4k rpm before it was kicking down into 4th. Then I was on the motorway last week, and all of a sudden, the car locks itself into 3rd gear and gives me a Transmission Service Urgent message. Wooppee Doo thinks I.

Well I wasn't too far from a Volvo dealer when this happened, so I limped along and had them diagnose the fault. They traced it to 'TCM-002B 4th gear incorrect ratio'. The technician I spoke to (without looking at things in great detail) suspected it was a cracked radiator, leaking coolant into the transmission, thereby comprimising the lubricant, resulting in a busted box. He said there was a burning sell from the lubricant. Advised new transmission and possible new radiator.

The car is still under warranty, so the guys I bought it from had it flat-bedded to an auto transmission specialist, who has told me today that they've reset the codes, had a good old drive in the car and that it's driving fine; nothing wrong with it apparently.

And I'm like, 'eh?'

Ok, Volvo are advising a new transmission because they don't have the skill to repair the existing one. That's fine. But can the fault be 'cured' by just clearing the codes? Surely there's some underlying fault, and clearing the codes will just prolong the inevitable? The guy I spoke to at the specialist said there was no coolant in the lubricant (and this maybe tally's with what the Volvo tech said, who thought the lubricant was actually pretty clean looking).

Just a bit confused, and wondered if anyone had any thoughts / experiences, although I appreciate most of you guys have experience of D5s. I just want to make sure I'm not being screwed over with some dopey quick fix, and that the same thing or worse isn't just going to happen in a couple months time, but when the car is out of warranty.

Cheers,
Col

[Clan]

This particular problem is under investigation by volvo and a software to help will be launched sometime in the near future , you should go back to your dealer and ask why they havent read their service bulletins regarding this problem !If you have an xc90 they may be able to do a temporary software to help it .
Is the transmission oil milky pink , black or the usual bright red ? This is a very important question regarding the way forward ...

[poisondart]

Originally Posted by Clan

This particular problem is under investigation by volvo and a software to help will be launched sometime in the near future , you should go back to your dealer and ask why they havent read their service bulletins regarding this problem !If you have an xc90 they may be able to do a temporary software to help it .
Is the transmission oil milky pink , black or the usual bright red ? This is a very important question regarding the way forward ...

Hi Clan, Many thanks for your reply.

The volvo tech who looked at the car reckoned the transmission fluid looked pretty good. I only quickly looked at it - it was definately not milky pink. I don't think it was black, but it didn't look bright red either. What does black fluid indicate and what does milky pink fluid indicate?

The garage it's with (not a volvo garage) have just reset the codes and now everything appears fine, and my worry is that this is simply a temporary fix, only masking a real problem...

Cheers,
Col

[Clan]

These gearboxes are remarkably good at keeping their fluid clean and red , milky pink is water from a leaking oil cooler this will wreck the gearbox , Black oil is a seal in the left drive shaft allowing gearbox oil into the CV joint believe it or not , this contaminates the gearbox and wrecks it also .
I would go back to the dealer , make them aware that they should be looking at the latest bulletins for any fault that comes in , and if you have an XC90 there may be something they can do with the software before the main software "help" comes out shortly ..
what is going on is the lock up clutch in the torque converter is slipping , what the software can do is increase the oil pressure to clamp the clutch tighter ...

[poisondart]

Originally Posted by Clan

These gearboxes are remarkably good at keeping their fluid clean and red , milky pink is water from a leaking oil cooler this will wreck the gearbox , Black oil is a seal in the left drive shaft allowing gearbox oil into the CV joint believe it or not , this contaminates the gearbox and wrecks it also .
I would go back to the dealer , make them aware that they should be looking at the latest bulletins for any fault that comes in , and if you have an XC90 there may be something they can do with the software before the main software "help" comes out shortly ..
what is going on is the lock up clutch in the torque converter is slipping , what the software can do is increase the oil pressure to clamp the clutch tighter ...

Ok then.

So is it fair to say that there essentially isn't anything wrong with the box? Given that, at this stage (and without having the car here to look at) the ATL fluid is ok (what the volvo tech said), and that the car seems fine after having reset the code?

Surely if there was something majorly wrong with the box (i.e. mechanical), and it had been damaged by oil or coolant, it wouldn't be ok now after resetting the code?

Is this a software issue? Or a duff box that can be fixed with a software upgrade? Do you know when the software update is due?

Cheers,
Col

[Clan]

Originally Posted by poisondart

Ok then.

So is it fair to say that there essentially isn't anything wrong with the box? Given that, at this stage (and without having the car here to look at) the ATL fluid is ok (what the volvo tech said), and that the car seems fine after having reset the code?

Surely if there was something majorly wrong with the box (i.e. mechanical), and it had been damaged by oil or coolant, it wouldn't be ok now after resetting the code?

Is this a software issue? Or a duff box that can be fixed with a software upgrade? Do you know when the software update is due?

Cheers,
Col

If the fluid is ok it is a bonus , . It is probably a bit of both , poor programming not allowing for wear when deciding on the operating oil pressure maybe .
All you can do is liase with your dealer once he has read the bulletin.
Have you an XC90 ?

[poisondart]

Originally Posted by Clan

If the fluid is ok it is a bonus , . It is probably a bit of both , poor programming not allowing for wear when deciding on the operating oil pressure maybe .
All you can do is liase with your dealer once he has read the bulletin.
Have you an XC90 ?

Yes, I do. 2004 T6 Exec.

Ok, so to Volvo it is then. Do you know when the bulletin is due? Does it have a reference? Just so I can arm myself with as much info as possible. I can just see me being laughed out the door of the Volvo dealers you see. And I'd have to get past the ppl on the service desk too.

Many thanks for all your help,
Col

[hancym]

I've just read this. I'm also interested in this software release. Am I correct in interpreting all the comments here from Clan that the release will allow for greater pressure on the torque converter and thereby not allow it to slip as much when you put your foot down? I have a 2004 T6 Exec and to be honest I find that compared to all the other autos I've driven BMW X5, Merc ML etc. the XC90 box on my car slips the clutch like buggery when you actually want it to put some drive to the wheels.

[Clan]

The greater oil pressure will clamp the torque converer locking clutch up tighter to prevent it slipping i guess when driving at a fixed speed , the clutch lets go when you demand power so if you have not got the fault message up and a fault code stored it wont help you . your clutches arent actualy slipping otherwise you get fault messages up .

[hancym]

OK I see now. Perhaps I used the wrong term of "slipping”. What I meant to describe is the torque converter converting torque rather than locking the drive. I do find that the smallest of power demands on the throttle seems to unnecessarily allow the converter to rev the engine rather than putting the power to the wheels in the way you would expect a manual box to do so with the clutch locked in place (if I've explained that well enough)

So am I to understand that the oil pressure to the torque converter can be tweaked by the Stealership to perhaps prevent this?

As I mentioned, in comparison to a few others I've driven over the past months mine does not seem to be as "nice" to drive. I don't have the control from throttle to wheels, there is a large amount of what I would explain as unnecessary hysteresis..... a bit like fly a hot air balloon. I have to anticipate when I need to move a put my foot down before the event. Or have I been spoiled by 30 years of a manual box!