Automatic Transmission Fluid change: For or Against?

cadaliac

On a different thread I posted about an ATF chnage. There were some interesting thoughts about changing the ATF in different gearboxes. Here is what I posted:

"I bought a 97 E200 about 2 months ago. The box is perfect but it does take longer to engage gears when the fluid is cold. I spoke to a few people and they recommended that I should not open the box at all.
Some Mercedes mechanics say that when you change the fluid, it can have an adverse affect on the box and it actually runs worse!!
There is only 102,000 miles on the car so I think I will leave it for now.
I still find it hard to believe that a fluid change can have an adverse affect though...."

Some people believe that "opening the box" is the wrong thing to do. Some people think that it is rubbish and a recommended fluid change should be done every 100k or so depending on the manufacturers recommendation.

What do you think?

Owen

I'd be of the school of thought to do it. I just did it on the Smart (A whopping 1.4 litres of transmisison oil), and if I was holding on to the 75, I'd probably do it if it reached 100k. Having said that, plenty of 75 owners out there don't, and don't have issues.

In the oil that came from the Smart's bangtronic and in the oil I saw changed on an E class a few weeks ago, there was a bit of swarf inside - so even though the units are supposed to be sealed, it's probably no harm to do it. Mercedes even sell an extremely long dipstick so you can change the transmission oil on their units.

cadaliac

PaintDoctor wrote: »

I'd be of the school of thought to do it. I just did it on the Smart (A whopping 1.4 litres of transmisison oil), and if I was holding on to the 75, I'd probably do it if it reached 100k. Having said that, plenty of 75 owners out there don't, and don't have issues.

In the oil that came from the Smart's bangtronic and in the oil I saw changed on an E class a few weeks ago, there was a bit of swarf inside - so even though the units are supposed to be sealed, it's probably no harm to do it. Mercedes even sell an extremely long dipstick so you can change the transmission oil on their units.

Yeah, the sealed for life ethos is a bit of a joke really. I think the negative thoughts towards the change are fueled by horror stories about contaminates getting into the box when open. Then the box gets worse you could end up having to replace the box eventually. Surely you should be able to avoid contaminating the fluid when changing....

Anan1

I'd do it, regularly.

unkel

PaintDoctor wrote: »

it's probably no harm to do it

Well that's the question. In a massive survey in the US of BMW 5 and 7 series owners, there were plenty of cases of people servicing their perfectly well running autoboxes only to run in to trouble shortly after. After doing quite some research, I decided a few years ago not to change the transmission oil in my 13 year old 140k miles 7-series. The box was running very smoothly at the time.

Now if the box had not been perfect, I probably would have gone for an oil change alright...

stealthyspeeder

I recently paid 2,200 sterling for a gearbox refurbishment on a "sealed for life" unit.

I will be changing the fluid at ZF (the manufacturors) guidelines rather than taking Audis approach in the future.

cadaliac

I'm not sure if ZF make the E200 box or not. Do you have to open the box for this job or is there a way of draining the fluid without removing the sump?
I presume not if you have to change the filter and gasket.

Matt Simis

I changed it on my Audi, at 175k miles. If I hadnt changed it I wouldnt have found out it only had 1/4 of the fluid in it!?

Anan1

unkel wrote: »

Well that's the question. In a massive survey in the US of BMW 5 and 7 series owners, there were plenty of cases of people servicing their perfectly well running autoboxes only to run in to trouble shortly after. After doing quite some research, I decided a few years ago not to change the transmission oil in my 13 year old 140k miles 7-series. The box was running very smoothly at the time.

Now if the box had not been perfect, I probably would have gone for an oil change alright...

I remember reading that about AUdi too. Mind, if those 'boxes had had their fluids changed regularly rather than for the first time at high mileages, they'd probably have been fine.

kuro2k

I have a 96 jap import hilux surf. I wasn't sure if the gearbox oil was changed before it was imported but with 180km on it last year I contacted a highly respected gearbox specialist in Cork for advice.

They advised to always leave it alone unless you can 100% guarantee it has been changed on schedule from new. I left it alone but I do check the level every so often, I'm now at 200km and I haven't experienced any problems

SilverBell

cadaliac wrote: »

On a different thread I posted about an ATF chnage. There were some interesting thoughts about changing the ATF in different gearboxes. Here is what I posted:

"I bought a 97 E200 about 2 months ago. The box is perfect but it does take longer to engage gears when the fluid is cold. I spoke to a few people and they recommended that I should not open the box at all.
Some Mercedes mechanics say that when you change the fluid, it can have an adverse affect on the box and it actually runs worse!!
There is only 102,000 miles on the car so I think I will leave it for now.
I still find it hard to believe that a fluid change can have an adverse affect though...."

Some people believe that "opening the box" is the wrong thing to do. Some people think that it is rubbish and a recommended fluid change should be done every 100k or so depending on the manufacturers recommendation.

What do you think?

On the shifting issues that you note with the box,
My 300CE (1991) is slower to upshift and shifts harder until the oil warms up. I dont think its a fault with the box. All the best.

Padraig Mor

Big time conflicting stories alright. My Lexus has a 'sealed for life' box. However, despite being a Lexus Ireland car, only serviced in their 'official' garage, they changed the ATF around the 60k mark IIRC. And the same car is required to get fluid change at 90k in Canada.....

Voodoomelon

Anan1 wrote: »

Mind, if those 'boxes had had their fluids changed regularly rather than for the first time at high mileages, they'd probably have been fine.

This is very true. In my opinion, if its under 100k miles, give it a lash. I did mine at 82k miles and the fluid was black. 15k miles on it since and not a single hiccup.

anthony4335

Has anyone done it themselves ,how easy of a job is it? is there any special tools needed to do this?

cadaliac

SilverBell wrote: »

On the shifting issues that you note with the box,
My 300CE (1991) is slower to upshift and shifts harder until the oil warms up. I dont think its a fault with the box. All the best.

This would lead me to not bother changing. Well, in the scene that there is nothing wrong with the gearbox.
I am also a bangernomics man (car #2 in fact) and I am just wondering about the cost implications.
Obviously if I do a successful change, it will enhance the car, but if it goes wrong - the car wont be worth fixing. I don't think it warrants a change at the moment TBH.

daRobot

I'd definitely change it. That's what ZF say, and they make the things.

'Sealed for life' is just sealed until the 60k 2/3 year warranty is up.

Anan1

SilverBell wrote: »

On the shifting issues that you note with the box,
My 300CE (1991) is slower to upshift and shifts harder until the oil warms up. I dont think its a fault with the box. All the best.

Probably not the case with the 124, but some cars are programmed to change up later when cold - I think it's to do with bringing the cat up to working temp more quickly.

Voodoomelon

anthony4335 wrote: »

Has anyone done it themselves ,how easy of a job is it? is there any special tools needed to do this?

Yup, I did it here: http://www.boards.ie/vbulletin/showthread.php?p=62438527

Not an easy job, but not rocket science either. Make sure you have the right bits and wrenches before you start or a second car handy to nip to a factors and get whatever you're missing.

As a minimum you need a new gasket/filter kit and new ATF fluid if you plan on dropping the pan. Here's before and after:

Matt Simis

Make sure you read up on if your car needs a special process. The Audi A8/S8s need to be lifted (all 4 wheels) off the ground and run through the gears to "suck" up more fluid. Without doing this you only get in 4litres, doing this correctly you get 9litres in there! :eek:

I think many independants assume all Autos are just fill till dribbling out the drain fill plug affairs, not true.

SilverBell

Matt Simis wrote: »

Make sure you read up on if your car needs a special process. The Audi A8/S8s need to be lifted (all 4 wheels) off the ground and run through the gears to "suck" up more fluid. Without doing this you only get in 4litres, doing this correctly you get 9litres in there! :eek:

I think many independants assume all Autos are just fill till dribbling out the drain fill plug affairs, not true.

I think in this case, the gearbox is not meant to be refilled.... heh heh!! "Sealed for life" dont you know!! With oil that lasts forever.:pac: