Automatic transmission fluid change

[Bat21]

Did an transmission fluid change today. Decided to do a drain then refill then a second drain to try and get as much of the old fluid out.

I was only getting about 4.5 litres out despite leaving it drain for a couple of hours. I realise there would still be some in the box and torque converter but now having read the manual I see the capacity is 15 litres

So going by that I have only effectively replaced a third of the oil

How do you guys do an autobox oil change?

 

[Gary820]

I go for drain, fill, drive then repeat, had to do it a few times when I got water in the box. Did have the sump and oil cooler off at one point too but was mostly clean.

 

[t1pper]

I swap out 4.5 ltrs anually it has kept my fluid looking nice and fresh.
Last time I dropped the sump and replaced the strainer and cleaned the magnets, everything was very clean with nearly no build up of debris even at 200k miles.
I believe you can have a complete system flush to replace all the fluid but I am happy with my routine.

 

[guyc]

Would using a Pela or similar extractor get more out?

 

[Bat21]

I swap out 4.5 ltrs anually it has kept my fluid looking nice and fresh.

I think this will be my strategy from now on.

 

[Chas]

When my box got water in it we went (Clive and I, well mostly Clive) for drain, fill, drive then repeat, IIRC it was 5 times before the milkiness disappeared

 

[Chris]

If you follow the schedule and only replace that which drops out, that IS the procedure. It's a refresh really not a replace. It's all that's required. I did mine this weekend too and swapped the throttle cable at the same time.

You can't physically drain the entire system unless you take the torque converter out and tip it up. The amount you'd need to put through it to flush it out completely would be considerable. It would probably involve connecting something to cooler pipe system that goes to the rad and pump fluid round.

 

[Bat21]

Thanks again folks.

I think I will do a drain and refill of the gearbox once a year to keep it in as good a condition as possible.

 

[t1pper]

Do not forget if you want to be really pro active clean/swap the strainer.
It will surely give you an idea as to the overall condition of the box if you examine any debris found on the magnets and strainer.
Mine was thankfully spotless so keeping going with the regular swaps makes sence for me.

 

[Lorin]

The amount you'd need to put through it to flush it out completely would be considerable. It would probably involve connecting something to cooler pipe system that goes to the rad and pump fluid round.

I did this and it was a considerable amount of ATF. I found a gearbox specialist with the pump that connects to the cooler pipes. Because I wanted to replace the ATF with Transmax Z that is fully synthetic, they first rinsed out the old ATF with 25 litres of cheaper fully synth ATF. Took it for a drive. Then used 25 litres of Transmax to complete the fluid change

Did I notice any difference......? Nope, but I am hoping it helps extend the life of the box.

 

[Chris]

Wow!

 

[mike smith]

Ok i may have something to add to this. On the weekend i did a trans fluid change. I followed advice on here and only add what i took out. Well that didnt work. I dropped the pan new filter and cleaned magnets. I put in what i thought was the right amount. Started the car, no gears. I panicked. Turns out i had not put anywhere near the right amount of fluid in. I was not aware to fill car you had to have the engine running, i do now. The gearbox cluncked away trying to get into gear. I chaecked again with the engine running and found out i was still low on fluid, i added another litre, still not enough, so i added another, now its running a bit better. Over all i have added way more than the book says. One book says it takes approx 7.4 litres if you just drain through the plug. Another on says it takes 15 litres if you do what i did and that is a complete change and dropping the box.

To be honest i still am not sure if i have enough. A mechanic told me, if the fluid is too low the gearbox will be trouble and wont like going into gears, and thats what has happened to me. I have added another litre a short time ago and will test drive it when getting grand kids from school. I will post a follow up to this.

Please i am new here and in no way am i trying to teach more experienced people than me what to do. I had a M class Mercedes and was spoilt because of all the electronics, it virtually told you when to take a pee, it had tha many warning lights, so going to a basic vehicle, 105 series 4.5 cruiser, i am having to learn all over again by trial and error. So please be careful how you fill the trans.

 

[fbnss]

Did you cycle through the gears with engine running as well? (Moving the gear stick to all positions)

 

[Chris]

Glad to hear it's coming back together Mike. Yes you are correct, generally you only need to replace that which you draw off, but if the level is too low to begin with then you have to replace that as well to be right. Now, it's odd that the vehicles generally run ok with too little fluid before you change it but don't afterwards. I don't have an explanation for that but it is quite common. It's maybe something to do with the fluid draining from valves etc that just don't fill up again once drained. Hopefully once you're up to the correct mark, you'll be flying. Your autobox will certainly thank you for it.

 

[mike smith]

Did you cycle through the gears with engine running as well? (Moving the gear stick to all positions)

Yes mate, i learned my lesson

 

[clivehorridge]

It took us ages to get Chas’ box to work anywhere near how it should.

With the river water in the box, it’s was like mayonnaise. We dropped what we could, IIRC about 4 lt, then refilled.

Cycled the gears with the engine running, then Chas went around the block using all gears including reverse, and we repeated the process.

I recon we must have put 20 lt through that box before the ATF came out pink.

It got him the 3,000km home, but reverse was still cranky, and since then he’s had a rebuild.

So, if you want to play in the river, my advice is don't. If you do, make sure your breathers are secure and high enough not to drown it. Then keep your fingers crossed that the shaft seals are good enough to keep water out...

 

[SeaJay]

and if you have a close look at the breathers from the transfer and trans mounted to the trans dipstick there open at that height, they dont go into the dipstick tube

 

[mike smith]

Ok this is where my lack of knowledge kicks in, i have no idea what you are talking about. What breather pipes, where are they, and what do they do, please dont say breath, that would be too easy. I have had a look in the manual and on the web for these pipes, but buggered if i can find them.

 

[SeaJay]

Mike I have an 80 series with the A442F transmission, I think its what will be in yours, but look on the build plate on the firewall to confirm, it will tell you the engine, trans and diffs fitted. The breathers vent the trans and transfer so they dont build possitive or negitive preasure inside them, on the 80 they go back to a fitting about 6 in below the trans dipstick, on the dipstick tube

 

[mike smith]

Its me again, unless you have a picture or a video of this, then im an idiot for not understanding what is obvious to many people, im really sorry, but i still dont understand, its no you its thick old me.