I just did a full fluid change on my automatic gearbox, so I thought I might share how I did it in the hope that it will help some one else and save them some $$.
Now as we all know a auto gearbox has no drain plug, and dropping the pan is a real PITA and not much fun when you do not have accesses to a hoist also dropping the pan will only get about 40% of the old fluid out if you did not already know that.
1st up get the ATF fluid you require and MAKE SURE IT IS THE RIGHT TYPE please, But make sure you get around 2 more litres than the transmission holds.
Next thing you need to do is find the fluid OUT line that runs from the transmission to the transmission cooler, there will be 2 lines The (IN) line and (OUT) line, Just follow each line and you should be able to figure out which line is which. My fluid run’s from the transmission to a side tank on the Engine’s Radiator then to a secondary cooler out in front then back to the transmission (So finding the out line was easy).
What I Did.
Removed the fluid out line from the secondary cooler and taped it to the handle of a 10-Litre bucket, Had all the new bottles of ATF ready to go and a 1-Litre measuring cup to pore the new stuff back in with. Start the engine and pump 1-Litre out (Will take about 45 seconds), then stop engine and quickly put 1-litre back in and repeat the processes till you have pumped out what you have put back in. Then reattach cooler line and check level, add some more fluid if required and go for about a 15k drive then recheck fluid level and do a final top up if required.
** The aim of the game is to do it as fast as possible to minimise mixing of old and new fluid there will be a small amount of mixing but you will change 90% of the old stuff, Having 2 people to do this is the best way, one works the engine wile the other guy putt’s fluid back in, If you are good you could pore the new stuff back in as the old stuff pumps out.
Why did you get 2 extra Litres of fluid??
Well as there will be some mixing I pumped a extra litre of the new fluid out to minimise mixing and
well the other litre is just spear encase you come up short. Also remember the filter in the transmission need’s to be changed at-lest once in it’s life so if it’s up around 150,000k’s and still on the Original filter change it, but remember the pan needs to be dropped to do this.
One last thing, there might be a bit of back flow thro the IN line from the transmission back into the cooler and then out of it, so just put a bucket under there as
well, I over looked this and had about 1 litre of dirty fluid flow out before I realised.
## if you Auto does not have a Dipstick (some don’t) then this will not work, so you are back to a pan drop or power flush. Remember on
well-travelled autos a power flush can cause problems so maybe just stick to a pan drop.