What is the latest consensus on the best course of action for preventative maintenance on my 06 S/C gearbox - some say just do megaflush and fluid change, others say just change the pan/filter and fluids and I have seen others even say just do the fluids?

My personal view - based on admittedly limited experience - is that I will continue with "standard" drain & fill procedures NOT using megaflush or similar.
Having done 1 pan change I'm sceptical of the benefits unless the drained oil is full of debris. The filter is not very fine, so seems only capable of catching large bits.
To me it's interesting that ZF still do not recommend megaflush type oil changes for either the 6 or 8 speed gearboxes - probably because of the potential to get it wrong IF not controlled correctly.
I'm sure it can be done well, but it's far more operator dependant than a manual change.
From what I've seen "third hand" many of the megaflush type operators also don't use the recommended ZF Lifeguard fluid - which I want in my gearbox. Paul,
2001 Discovery 2 TD5, 211,000 miles & climbing
2006 FFRR TDV8 Vogue 145,000 miles & climbing
Member of Midland (Land) Rover Owners Club, www.mroc.co.uk

The can of worms has been opened
Megaflush for me  2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
New Defender D300 90 on order so "Rory" will be going to a new home....!
1974 Series 3 Lightweight = "Millie"
My preferred specialist: www.glenrands.co.uk
--------------------------------------------------

Changed mine using the drain method.

ZF8 gearboxes are fitted to loads of cars and not one of them recommends flushing. I'll stick with the ZF guidance, after all they made the thing. Christian.


Current Cars
2011 Range Rover Vogue SE
2020 BMW M4 Competition
2019 BMW X4

My RR Blog: www.facebook.com/L322Project
or
https://www.fullfatrr.com/forum/topic61540.html

From the horse’s mouth:

Thank you for your enquiry.

ZF do not recommend any flushes for the transmission. If you are experiencing any issues with shifting quality then it is strongly recommended that you have the vehicle inspected by an experienced technician.

Kind regards,
ZF Technical Support 2011MY 4.4TDV8 Autobiography Baltic Blue
TVR Griffith
Alfa Romeo Mito QV

Drain and refill here  Kev

2014 L405 RR Vogue SE 4.4 SDV8 in Corris Grey
2010 L320 RRS HSE 3.0 TDV6 in Stornoway Grey

I’ve never had a gearbox problem but have always carried out preventative maintenance and done many partial drops and refills and on my current car a flush.

As far as I can see both work very well.

I have personally flushed well over 1,000 gearboxes, between ZF 6/8/9HP and the AW boxes (FL2/Evoque), some with filters and some without, and we've never had an issue

That said, we do have a clever machine that measures pressure and flow, and matches this when carrying out the flushing process

RR2B wrote:

From the horse’s mouth:

Thank you for your enquiry.

ZF do not recommend any flushes for the transmission. If you are experiencing any issues with shifting quality then it is strongly recommended that you have the vehicle inspected by an experienced technician.

Kind regards,
ZF Technical Support

Exactly! Don't Megaflush a box with issues as it seems to make it worse. Deal with the issue. Common sense. I see Megaflush as part of preventative maintenance program on a box in good condition and wanting to keep it that way  2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
New Defender D300 90 on order so "Rory" will be going to a new home....!
1974 Series 3 Lightweight = "Millie"
My preferred specialist: www.glenrands.co.uk
--------------------------------------------------

I did sump change and 3 x full drain and fills to change all the fluid

Was a tedious process and effectively you are throwing out some new fluid but in the end you have all new fluid and you have complied with ZF rules if you care about that.

1 x drain & fill will only change IIRC less than 50% of the total fluid to the fluid in the cooler and TC

. Cheers, Greg
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
2011 Vogue SE 4.4 with lots of toys in Stornaway

Follow up from the horse's mouth:

Hello,

There are a variety of flushing methods and systems available, some recycle fluid. This can cause cross contamination and further damage the transmission. Additionally additives used in some flushing methods can damage components too.

As a result we do not recommend any flushes for our transmissions.

Kind regards,
ZF Technical Support 2011MY 4.4TDV8 Autobiography Baltic Blue
TVR Griffith
Alfa Romeo Mito QV

Mega Flush - Done it as preventative maintenance, best way to change oil...

RR2B wrote:

There are a variety of flushing methods and systems available, some recycle fluid. This can cause cross contamination and further damage the transmission. Additionally additives used in some flushing methods can damage components too.

ZF Technical Support

I'd love to see a flushing machine that recycles fluid. That would defeat the whole purpose of a flush

Our machine was not particularly cheap, but it is very clever

It measures the pressure and flow of the outgoing oil, and refills using the same flow and pressure
It is clever enough to have the feature of Zero Cross Contamination, where it purges the lines of any old fluid and replenishes with new fluid (handy, as qe flush lots of 6/8/9HP boxes, and also the Aisin Warner boxes in the Evoque and Freelander 2. Both use a very different oil, and are not compatible)

Also, not keen on chemical flushing, but have used it to good effect in the past...

It sounds as though ZF have given a blanket "not advised" as there are too many variables with cheaper machines, which can cause damage