Gearbox Oil confusion.

[spikeyadrian]

Hi Guy's,
I've just had a recon Midland gearbox & clutch fitted in my 2004 Cooper.
Cost me £600 inc a 6 month warranty.
Now i'm a little confused, the guy who fitted the gearbox & clutch said
he used mineral based oil in the gearbox instead of the usual Synthetic MTF94
He said he didn't rate the Synthetic Oil and in his opinion, the mineral based
oil was better.
Any truth in this statement, or do you think he used mineral based oil because it's cheaper and he only guarantees the gearbox for 6 months for this reason?
I've always thought synthetic gearbox oil was far superior to Mineral based oil?
I want this gearbox to last as long as possible, should i change the oil to synthetic?

[The Nun]

Problem is.... if its under warranty and you change the oil they put in as they feel its better and the box fails during the warranty period, they might blame you for swopping the oil and thus cancel the warranty?
You need to be a little careful whilst the warranty is in force as to what you or dont do.

[arbi12]

just change it he will never know dont agree that mineral is better than synthetic, funny that every clutch kit i fit has 2 year warranty on parts. but i know garages that swear wheel bearings only have 1 month warranty?

[cjm]

Please correct me if I'm wrong but I'm not sure MTF94 is synthetic.

I've used it in my '09 MCS (MTF94 sticker on the gearbox) and improved the gearchanges in the '12 MCS (no advice sticker) that replaced it already.

I keep 3 litres on the shelf now because it works so well but I've never seen 'synthetic' claims on any of the packaging.

Incidentally, I've kept in the back of my mind that I'll change it frequently (perhaps even yearly) since it isn't synthetic and it's an easy job.

update: just checked. Can't see any 'synthetic' claims on my Carlube MTF94. There was nothing synthetic on the Landrover MTF94, that I used last time, either...

[mab01uk]

MTF94 (Manual Transmission Fluid)
http://www.kewengineering.co.uk/Auto...OVER%20MTF.pdf

Available under various brands (I buy from a local Land Rover Dealer as usually in stock)
MTF 94 | Texaco engine oils and lubricants

[Morallye]

I just came across this thread.
Thought worth pointing out that the Carlube MTF94 is in fact a Mineralis based transmission fluid.
This is the one that Mini recommend for the Midland g.boxes.