Gearbox Oil confusion.
I've just had a recon Midland gearbox & clutch fitted in my 2004 Cooper.
Cost me Ł600 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?