The time has come to change the gearbox oil on the SC.

I've had quotes from Mikey and Mackie's Transmissions in Glasgow to have the sump replaced and the oil changed but I keep thinking about doing it myself as I've got time off work next week.

I've seen the ZF Lifeguard 6 oil on eBay for £20/litre.

This morning I got in touch with Millers Oils Technical Team in Yorkshire who said their equivalent of the Lifeguard 6 is Millermatic ATF-DM. On the spec sheet they've sent me it says on it ZF 6HP 26 and M1375.4 which I believe is the standard that Shell manufacture the oil to for ZF.

The one thing that has caught my eye is that on the same spec sheet it lists it as being a compatible replacement for the LT71141 used in the 5 speed box and I was under the impression that they were totally different oils!

Millers Oils charge £62.50 for a 25l tub of their oil so there's a massive difference in price but I don't want to save on oil and have to foot a massive gearbox rebuild bill!

Spec Sheet:

Click image to enlarge

"The one thing that has caught my eye is that on the same spec sheet it lists it as being a compatible replacement for the LT71141 used in the 5 speed box and I was under the impression that they were totally different oils! "

That makes sense. It doesn't mean you can use LT71141 in a 6 speed. It's simply compatible one way.

Buy the genuine. Buy once. ZF have replied to other owners of ZF boxes explicitly stating why they recommend a specific oil and i've pasted it in this forum in the past (i'd need to go looking for it) They also comment that it costs them a lot of £££ for the stuff as it does us. V8 or else ...

Advanced Factors do Meyle stuff which is supposed to e the same for under £10 a litre. Been discussed on here before.

I got mine from here, http://www.lrparts.net/catalogsearch/result/?q=lifeguard+6
Recommended by forum member Sako243.
Filter, oil at a good price.

Steve. 1968 Series IIA Pastel Green, nearly there project

I would personally only use the ZF Lifeguard 6.......its the correct oil. I used Mackies when I had my SC to change the oil, I also changed the multiplug seal at the same time as a precaution......it makes sense as you need to drop the sump to change it and sods law it will leak at some point..... Stolen / Gone: 2006MY Supercharged LPG Autobiography - Zambezi Silver with Sand/Jet/Jet Oxford Leather.....

I've used the millermatic DM multiple times in all of my 6hp trannys that I've owned. This includes the XK, l322, DB9 etc.

Never had a problem and always been cheap from here

http://www.fmsap.co.uk/

I've done a huge amount of mileage running the Millermatic fluid, anyone buying the overpriced original fluid is a bit of an idiot IMHO.

Don't skimp on the filter though.

I made a video for the Jag owners:

AFAIK It's not about the oil, it's about the additives... the manufacturers make an oil to a particular spec and that oil advertised is the same spec... a bit like everyone makes a 5w-40 motor oil... ZF specified what additives should go in the oil... these won't necessarily be in the cheaper oil... ipwn's experience is probably what will happen 99% of the time if you use the cheaper oil but...

Having changed my box once I don't want to take it out again so I'd pay the extra for peace of mind, can't see the point of saving a few quid and "maybe" doing it some harm...  Pete
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2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
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ipwn wrote:

I've used the millermatic DM multiple times in all of my 6hp trannys that I've owned. This includes the XK, l322, DB9 etc.

Never had a problem and always been cheap from here

http://www.fmsap.co.uk/

I've done a huge amount of mileage running the Millermatic fluid, anyone buying the overpriced original fluid is a bit of an idiot IMHO.

Don't skimp on the filter though.

I made a video for the Jag owners:

It can't be that critical, the thermal expansion of oil is not a lot... a 20deg C increase will give a volume increase of just over 1%, negligible in the great scheme of things....  Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

The running moves the fluid around as well. Recently did my 6 speed BMW auto box new pan with filter in and oil, could only get 2 of the seven litres in cold then more each time I ran a heat cycle. Temperature is way more than 1%

rangie47 wrote:

ipwn wrote:

I've used the millermatic DM multiple times in all of my 6hp trannys that I've owned. This includes the XK, l322, DB9 etc.

Never had a problem and always been cheap from here

http://www.fmsap.co.uk/

I've done a huge amount of mileage running the Millermatic fluid, anyone buying the overpriced original fluid is a bit of an idiot IMHO.

Don't skimp on the filter though.

I made a video for the Jag owners:

in your video you don't mention about monitoring of the oil temperature when filling ,
I thought this was a very important part of refill levels ?