My 1.6 Focus Petrol Automatic has 110,000 mls up. I don't believe it has ever had the Auto Gearbox oil changed. When I was getting some work done three years ago at around 95000 mls I asked them to change the gearbox oil but they said it's better just to leave it changing can cause problems? Is this true? Thanks 

1 hour ago, tesco500 said:

I was getting some work done three years ago at around 95000 mls I asked them to change the gearbox oil but they said it's better just to leave it changing can cause problems? Is this true?

Well Jeffery I'm pleased you didn't rush in to doing anything. Always better to have a think (3 years and another 15000 miles) before asking the question. 🤔

Yes it should have been replaced along time ago, actually about 3 times now. Given the age and the mileage I'd think it a bit late to worry about it now.

As it's now 17 years old, it's a bit late to be concerned. 

Now I'm not saying this is true of the Ford auto box, but some cars - e.g. VW group, Porsche, suffer from gearbox problems if the oil and any associated filters are not changed to schedule. I first noted this on a TV program - might have been an episode of Wheeler Dealers? - where they bought a Boxster whose owner was selling it cheap 'cos the gearchange didn't work, and had been told by a main dealer that it needed a new box. The mechanic did a gearbox service and hey presto - it worked.

AFAIK only the Powershift gearbox requires an oil change every 3 years, and your isn't one of those.

Unofix  and iantt - do me a favour don't reply to any future questions I have I can do without your 'help'

Edited November 15, 20223 yr by alexp999

It's not going to harm it to change the fluid, you will need to do a bit of research of how much and which fluid you need (probably just generic semi-synthetic). Ford will tell you it's sealed for life, but you should really change it at least every 40,000 miles because the fluid gets hot and starts to break down.

You won't get all of it out as a lot remains in the torque converter and cooling loop, BUT, you could drain and refill then 300 miles later drain and refill again.

Dirty fluid affects the hydraulic performance of the gear change pressures, torque convertor smoothness and shift solenoid performance.

It certainly won't hurt

There is no drain plug on yours so you will need a large tray and a new sump gasket, just drop the sump to drop the fluid

Measure how much came out, put two 3rds back in, start engine until warm running transmission between N, D & R once warm to get the fluid around the system and then check level and top up

Your transmission is model 4F27E by the way and it looks like you need MERCON V fluid.

Dry it holds 6.7 Litres, you'll be lucky to remove 4 litres