All,

I have a 1967 3.4 MK2 with BW35 auto trans. I am ready to get my MK2 on the road and cant seem to figure out what transmission fluid my BW35 auto trans requires. Everything I read says it was designed for Ford Type F. I called SNG Barratt and they recommended Dexron II. I searched the forum and do not see this being addressed before.

Can I safely use Dexron II? The serial number plate lists a bunch of auto trans fluids - Including: BP type A, Mobilfluid 200, Castrol Grade A, Shell T.6. I think those are Dexron compatible fluids.

Any help would be appreciated.

MG

 

Fluids meeting Ford M2C33F or G have the correct frictional characteristics for your gearbox. i.e. quick clutch pack lock up. Dexron II will allow more clutch slip & delayed lock up. This can lead to excessive temperatures & burnt clutches. I don't know how tolerant the BW35 will be of the incorrect fluid.

Ford & GM had totally different design philosophy back then. Ford with small clutch packs that required to lock up quickly & GM with large plates that could take a lot of slip & slow lock up.

ATF's of different types have friction modifiers in them to suit the clutch pack size & friction material used. The correct fluid should be used. A smoother change (lower shift shock) is not necessarily the best change. Too much slip for the design will lead to clutch pack failure. Friction Modifiers allow controlled slip & lock up for a specific design.

Type F & Type G Fluids also offer far better wear protection of gears etc. than Dexron II.

 

Hi Glyn, great explanation of the difference between the ATF's. When I fit back the Model 12 gearbox on the XJ I was planning to use this oil, https://www.opieoils.co.uk/c-1444-fo...-33fg-atf.aspx what do reckon of it? It has the Ford spec.

 

Hi Nigel. I don't know the brand. It has the correct spec.

 

Thanks Glyn, it has a good name in the UK - I'll give it a go.