ATF Change

[Tannaton]

If you have a set of traditional car ramps and use those to raise the front of the car only- you get more of the old oil out doing a traditional drain as the drain plug is towards the rear of the gearbox. Doing it that way on my XC60 with the TF80, I get almost 4 litres.

With repeated drain and fills and a good drive in between, the first change you will replace 57% of the fluid, after the next change you will have replaced 82% of the fluid, on the third change you will have done 92% of the fluid, if you go for a 4th change you will have 97% new fluid.

I think the most engine oil you will change on a service will be circa 90-95%.

That's more than good enough.

[Kev0607]

Originally Posted by gmonag

Unless you perform a proper flush, as described in VIDA, also referred to as the Gibbons method, the oil will not be a nice cherry red. Drain and fill only changes 2 litres, the total capacity is 7 Litres. Even doing it 3 times will not change the oil completely.

Doing a drain & fill, then driving the car for a few hundred miles before you repeat the process makes all the difference.

Draining & filling repeatedly, then cycling through the gears whilst the car is stationary doesn't give the cleanest results.

The gibbons method is great if you want to do the job all in one go, admittedly.

[XC90Mk1]

Originally Posted by Kev0607

Doing a drain & fill, then driving the car for a few hundred miles before you repeat the process makes all the difference.

Draining & filling repeatedly, then cycling through the gears whilst the car is stationary doesn't give the cleanest results.

The gibbons method is great if you want to do the job all in one go, admittedly.

Switching the rough P, N, R and D in the drive does little. You really do need to drive between changes...

[Tannaton]

I'm not convinced the gibbons method is actually that much better... if you pump the oil through the gearbox but don't drive it - there will be some valves, solenoids and actuators that don't have any flow and the torque converter will be loaded at the absolute minimum... so some old fluid will remain.

Just my two penneth based on my thinking.

[Kev0607]

I don't think any method will get all the fluid out, so there's always going to be traces of old fluid no matter what you do.

A similar scenario would be draining the oil from the engine via the sump... there's still going to be oil in the engine.

Realistically, multiple drain & fills over time with the vehicle driven in between changes would change 95% + of the old fluid.

The gibbons method probably does the same percentage wise, but the process is usually done in one go.

[gmonag]

I know the full flush is not popular here, but I have done it twice (DIY) at 100k and 160k. The whole process took less than an hour, used 10lt of fluid and left the oil cherry red. The gearbox was noticeably smoother afterwards.