I'm looking to change the oil in my L322 TDV8 4.4 8 speed gearbox (8HP70) as a preventative measure - no issues, but she's covered 100K and I've previously been hit with the costs of a gearbox and TC rebuild on the petrol L322

I've found what looks like a very good price for 10L of genuine ZF Lifeguard fluid and a Filtran filter @ £245 incl VAT and delivery from Oilexpert:

I would recommend a Megaflush. Plenty of folks around the country who do them and specialise on these 8 speeds. I had mine done for exactly the same reasons as you = preventative maintenance
Bodsy did mine on the drive Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
I use www.glenrands.co.uk Great independent specialist!
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Call him on 07770638023
Can't recommend him highly enough and bonus is he comes to you  Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
I use www.glenrands.co.uk Great independent specialist!
--------------------------------------------------

What about the filter with a megaflush, Rob. Isn't it a concern that it doesn't get changed? John
2008 Stornoway Grey 3.6 Tdv8 Vogue - SOLD
2005 TD6 Java Black Vogue - Written off!!
GAP iiD BT-Sold

I'm not an expert on that. Can of worms!
I had a perfect working box before and after the Megaflush  Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
I use www.glenrands.co.uk Great independent specialist!
--------------------------------------------------

 John
2008 Stornoway Grey 3.6 Tdv8 Vogue - SOLD
2005 TD6 Java Black Vogue - Written off!!
GAP iiD BT-Sold

I had the same query about the filter and Megaflush.. apparently not required on Megaflush.. Im booked in and due to get mine done in few weeks. Current:
- L560 Velar HSE R-Dynamic D180
- Peugeot 508 2011 - 2.2 HDi GT

Past:
- FFRR V 2010 - 3.6 TDV8
- Citroen C4 1.6i Petrol
- Mitsubishi Shogun 3.2 DID
- Peugeot 607 2.2 HDi
- Nissan Primera 1.8 SVE
- Honda Civic 1.6 VTEC

Yep. Concur from 3rd party expert opinion. Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
I use www.glenrands.co.uk Great independent specialist!
--------------------------------------------------

Another here who would recommend Bodsy and the mega flush ,he has done both my discos and the Range Rover with no issues

Thanks for the advice re. the Megaflush guys.

I can see the advantages in terms of replacing *all* of the original fluid and the ease, especially for Disco owners where getting the sump off is a pain, thankfully not an issue for FFRR's.

However, I'm still planning on dropping the fluid 3 times to change the fluid. I'd do this over the course of a couple of days to ensure good mix of old/new fluid.

By my calculations, this should resulting in at least 85% of the original fluid being changed if I get 4L out through the transmission pan drain hole, which most people seem to easily do if the oil is hot & thermostat open. Then carry out fluid drops / replacements every 2 years or 20K (around 4 litres per change), hopefully keeping it lovely and fresh.

In addition to enjoying working on my own cars (read glutton for punishment), I also want to have the sump pan off to fully evaluate the health of the transmission.

Cost isn't the issue, but this should cost no more than £290 all up to replace 85% of the fluid and fit a new quality Filtran filter.

If I can get 4.5L of oil out each time (which I've seen some people have achieved), then after 3 drops I should have replaced 90% of the original fluid and by the 4th drop 20K miles later it would be 95%, plus I'd also be replacing some of the (now) 2 year old fluid as well!

That's the plan - I'd welcome any thoughts, but definitely not wishing to re-start any arguments of Megaflush vs standard vs multi-drop. I love working on cars and have the time. I'm certainly not knocking the mega flush process in any way, if I was pushed for time I'd have it done that way myself.

Jon 1992 RR Classic 3.9 efi Vogue
2014 Disco 4 HSE
===================
Both my fatties now gone...
Previous: 2011 L322 4.4 TDV8 Vogue SE /// 2002 L322 4.4 V8 HSE /// 2009 Discovery 3 2.7 TDV6 XS /// 2004 Defender 90 TD5 /// 1993 110 V8 Snatch Landrover /// 2005 Discovery 3 2.7 TDV6 SE (Aus) /// 1990 110 Isuzu 3.9 County (Aus) /// 1976 Series III Trayback (Aus)

Personally I would go for the flush when compared to the cost for multi flush.. doesnt cost you more than £350 Current:
- L560 Velar HSE R-Dynamic D180
- Peugeot 508 2011 - 2.2 HDi GT

Past:
- FFRR V 2010 - 3.6 TDV8
- Citroen C4 1.6i Petrol
- Mitsubishi Shogun 3.2 DID
- Peugeot 607 2.2 HDi
- Nissan Primera 1.8 SVE
- Honda Civic 1.6 VTEC

Each to their own, no problems with that.

but,

I don't see the logic of performing a 'mega flush' at 100k miles and using new oil but then keeping the old 100k miles filter.

Would you do that with an engine oil change?

Best, Rich L322 3.6 TDV8 Vogue. 07MY
ML 320 7 Seat full leather etc. (The Black Pearl)

totally agree which is why I am contemplating changing the filter too.. Current:
- L560 Velar HSE R-Dynamic D180
- Peugeot 508 2011 - 2.2 HDi GT

Past:
- FFRR V 2010 - 3.6 TDV8
- Citroen C4 1.6i Petrol
- Mitsubishi Shogun 3.2 DID
- Peugeot 607 2.2 HDi
- Nissan Primera 1.8 SVE
- Honda Civic 1.6 VTEC