It appears that the correct fluid spec. for the Borg Warner DG 150 M gearbox is to `Ford ESP-M2C-33F/G´. There are several readily available makes, including the Millermatic UN previously mentioned, Comma AQF, and Gulf ATF-1. Note that Dexron II fluid is not recommended for Borg Warner DG transmissions. There is a school of thought that says a newly rebuilt gearbox will run better with a modern equivalent, for example semi-synthetic Comma AQM, also listed as suitable for BW applications. Different transmission fluids can appear to be identical but have very different characteristics, and it is not recommended to mix modern variants with older types (e.g. synthetic and mineral-based fluids should not normally be mixed). It is best practice only to top-up with the same make of fluid that is already in the transmission. If the fluid in the transmission is old and you are unsure what type it is, then best to drain it completely (from all 3 drain points) and refill with an appropriate recommended BW spec. fluid. I have recently done this using Comma AQF, and although the fluid removed appeared quite clean, the improvement in up-changes, especially from low - intermediate was very significant and well worth the effort. Posted by lacey giles 12/08/2012 08:14:23