Quote:
Originally Posted by gmonag
Here we go again - this old-wives-tale about flushing the gearbox doing harm.
The flush method (so called Gibbons method after a member who posted it here a few years ago) is the official method as described in VIDA. It is simple and quick to carry out and will change almost all the fluid on one go. Do it and your gearbox will improve!
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That is for a NEW gearbox!
Seriously, i have no axe to grind here but don't want people to use a method that HAS BEEN PROVEN to cause problems on older boxes of various makes. Why do Volvo continue to use it on higher mileage cars? For the same reason as all manufacturers do, they know sooner or later a seal will fail inside the box and necessitate a new gearbox - you can almost hear them rub their hands in glee at the thought of it!
It's NOT an old-wives-tale and how many old wives do you know that change their own ATF?
The debris comes from the natural wear of clutch packs (in one of mine) and brake bands (in the other) wearing because they are friction material. This causes dust, some of it metallic and this will ultimately settle at the lowest point through gravity. Using the sump-dump, preferably with an electric oil transfer pump down the dipstick hole with the car raised so the point where the diptstick enters the box is as low as possible, to remove the old fluid means more of that sediment/debris will be removed - there is a neck round the drain plug on many gearbox sumps which means the debris sits around the drain plug.
Something we both agree on though, old fluid is one of the biggest enemies for an auto box.