We want to change the oil in our IH 885 tractor transmission, it says in the manual to use Case Hytran [MS1209 spec] and have seen some other oils like Mobil 428 that claim to do a good enough job. But case say that it doesn't have some kind of necessary additive specific for the transmission. So does anyone know if there are any substitiutes and the likely effects of using them and if this additive is so important. It seems that this spec. they quote of M<S1209 only applies to their machines - what is so special about it? The dealer rep. is totally brainwashed with the idea that nothing will do the job that hytran does is he giving us BS or not?

Yes, he's giving you BS. Use hytran for the guarantee period, then you can change to another UTTO product with the right spec. Lots of Case and IH uses other brands without any problems.

Maybe the specifications of the MS 1209 explain something:

Case MS 1209 specification for a fluid suitable for use in certain hydraulic, transmission, power steering, axle, wet brake and other systems. Case market their own brand complying with this specification known as Hy-Tran Ultra©. Other fluids qualified to this specification by Case may be labelled as approved by Case and identified with names that include the Hy-Tran Ultra trademark. Kinematic viscosity @ 100º C ASTM D445: 6,2 mm²/S min. Apparent viscosity ASTM 2983 @ -20º C: 3500 cp max., @ -30º C: 15000 cp max.. Viscosity index ASTM D2270: 95-105, Flash point ASTM D92: 195º C. min, Pour point ASTM D97: -37º C. max, Aniline point ASTM D611: 91-110º C. Other test include, elemental analysis, foaming characteristics, oxidation/corrosion, water tolerance and gear wear.