Am I playing with fire?

[Tannaton]

Originally Posted by bananarama

I assume I would to reset the TCM because if I pump out most of the ATF in one go, the ATF quality has undergone a drastic change, and the TCM needs to know about this?

That would be best practice but not absolutely necessary. If you are changing the fluid for maintenance reasons and not addressing an issue, you should still change it anyway, it will prolong the life of your box.

[Volvocano]

Originally Posted by bananarama

I assume I would to reset the TCM because if I pump out most of the ATF in one go, the ATF quality has undergone a drastic change, and the TCM needs to know about this?

I'm not about for a few weeks, but should have some time at the end of August - So if you want to do a bigger flush and you need someone to reset your transmission adaption I can come down and do it - I'm only about 40 miles from Reading - I'd just incorporate it in a Sunday morning bike ride or something!

[monkeh]

Originally Posted by bananarama

I assume I would to reset the TCM because if I pump out most of the ATF in one go, the ATF quality has undergone a drastic change, and the TCM needs to know about this?

I doubt it, you're only removing about a quarter of what's in the system if you are lucky. You've got fluid tied up in the TC, clutches, valve bodies, cooler etc.

There'll be a good few litres in the converter. Given my experiences doing a partial fluid change several times in that manner, I'm sure the TCM would realise that the fluid is changing slightly and adapt itself.

[bananarama]

Originally Posted by Volvocano

I'm not about for a few weeks, but should have some time at the end of August - So if you want to do a bigger flush and you need someone to reset your transmission adaption I can come down and do it - I'm only about 40 miles from Reading - I'd just incorporate it in a Sunday morning bike ride or something!

I may take you up on that; thank you!

I'll see how the next change goes, which will be ~3L instead of ~0.9L

[Tatsfield]

After 3 changes at the 3 litre level, you are beginning to incur the rule of diminishing returns. Any final dilution of the old oil with the new to the levels of 80% to 90% is probably as much as you need to do as the cost for the smaller and smaller improvement become non cost effective and you'd then be better if you never used the technique at all and went straight to a workshop full drain and refill from the outset. However anything in excess of 80% is probably going to be more than adequate to improve the workings of the gearbox.

[bananarama]

Agreed! I just want to get to the stage where the oil is red, because ATM the oil is coffee black and stale smelling

Not long left, I've ordered 10L of WestWay AW-1, getting ready for the 3L changes.

[neilgorin]

I did this drain as much as possible and refill routine on a couple of cars in the past, it took more than three changes to get to the point where the fluid wasn't dark brown, but after the second change the shifts were smoother.

[al dm]

I am late to this thread, having only bought myself a lowly 2011 XC70 D3 2WD yesterday.

The car is basically immaculate, but has done 120,000 miles. Full service history etc and there is absolutely nothing wrong with it at all.

But....reading here and there about flushing the transmission and replacing the fluid got me thinking this was probably something I should do just for peace of mind.

So I popped into my local Volvo specialist (Doves near Horsham) and asked them about it. They said...."Nah, guv. It's sealed for life. No need unless you have been doing a lot of towing or taxi work. And it'll be pricey. At least two hours labour, plus fluids, parts, VAT etc..."

So - is the general wisdom here that it would be something that I should do? I am fully capable of doing the 3 litre drain/replace thing a few times. Not so sure about how to totally empty/flush it and replace all of the fluid though.

What say you???

[bananarama]

I'm no expert...

I've been doing the 3L drain/replace and it seems to be going well for now; I've got 2 more to go. Also, I have no idea how long it'll take the TCM to adapt.

If Volvo did this for you, I think part of the work would include taking the car out for a spin with new oil to adjust the adaptions via a computer.

[al dm]

Originally Posted by bananarama

I'm no expert...

I've been doing the 3L drain/replace and it seems to be going well for now; I've got 2 more to go. Also, I have no idea how long it'll take the TCM to adapt.

If Volvo did this for you, I think part of the work would include taking the car out for a spin with new oil to adjust the adaptions via a computer.

Thanks,

I think I will attempt the drain/replace procedure (but am also reading up on how to flush via the fluid lines to the radiator).

Going through the paperwork that came with the car, I found a service invoice from about 10K miles ago recommending changing the gearbox oil - but no paperwork to say it has actually been done.

So probably better safe than sorry....