Odd autobox problem

[sam303]

I have a 2003 Subaru Legacy 3.0R auto estate that has done about 103k miles. I’ve owned it for roughly six months and it’s been excellent so far. However there is one thing that is a bit odd: a reluctance to get off the mark when first started up. I start the engine and slot the autobox into ‘D’. If cold the car will sit for several seconds before actually starting to move forward. If I apply the throttle it will just rev, before finally ‘catching’ – not with any kind of lurch, but gradually – and starting to move off. Once on the move, even if not really warmed up, the car is much more immediately responsive going from ‘N’ or ‘P’ into ‘D’ – it ‘catches’ straight away and off you go.

Any idea what might be causing this?

[Dr Doofenshmirtz]

Oil level? Remember, it must be checked with the engine running.

[Mars]

My 2005 model does that. I think it's just the torque converter "filling up" if the car's left at an angle (mine is) or (perhaps) if the level is low. Mine does it once a month. Seems to resolve fairly quickly and never happens again that day.

[paintman]

Likely the filter in the autobox needs changing.
It's a common issue on ZF autoboxes (I don't know if yours is a ZF, but I would expect it will have a filter) as the weather gets colder & the fluid thicker as a result.

This is from Ashcroft Transmission's website:
When I start my Automatic Range Rover in the mornings it takes a while to engage drive, it has not always done this. This has become worse in the cold weather. Why?

It sounds like you need to change the filter! In the cold weather, i.e when the oil is cold and more viscous, if the filter is partially blocked it will take some time for the pump to draw oil through it. Once the oil becomes warm it flows more freely and can pass through the filter more easily. Hence the problem only occurs when the oil is cold. To remedy this problem your filter needs to be changed. This should be done sooner rather later to reduce the possibility of damage to the autobox, by the clutches 'slipping' during this slow engagement.