Computer for Trans Fluid Change???

[Lost C280]

I've just purchased a 1998 C280 Sport and I've been searching through the archives to get set to change the oil and filter in my transmission but I came across mentioning the need for a computer to drain the torque convertor of Trans fluid. The post mentioned the computer is needed to get it the transmission to a certain temp, etc. Wondering how necessary having this computer is?? Is there a method to drain the torque convertor without this computer???

Any input would be appreciated. Thanks!!

[SpEeDy230]

I Did my Tranny Fluid Change not too long ago and to drain the torque converter you have to get a socket (forgot the size) and turn the crank shaft to see the drain plug on the converter. Since your's is a 98 you have a electronic tranny, which means special MB tranny fluid from the dealership for $14.40

Good luck

[Rocky]

i haven't changed mine in 7 years. My Mech/friend told me don't bother to change it if i never changed it in regular intervals because the tranny is 'use to' the tranny fluid that's in there already.

[Lost C280]

Thanks for the input guys. There seems to be a lot of mystery around this subject. I've heard things from never changing transmission oil to changing it at very short intervals, also things like don't change it because the transmission will give anyways due to non-fluid related issues. The last was this computer required to drain the torque converter which completely baffled me as I'd never heard of this before. I've also heard a computer required to ensure the proper operating temperature of the transmission just to check the fluid level!!! I think I'll just go along with the good old change your fluids at regular intervals and buy myself a dipstick so I can monitor fluid level and condition myself. Leaving any chemical in my car "forever" doesn't seem all that wise to me, especially considering how much a transmission can cost. Again, thanks for the help!!

[Rocky]

Keep in mind tranny fluid's job is to lubricate and cool..not clean.

[Lost C280]

Rocky

I do agree that the purpose of ATF is not to clean, but it does do more than just cool and lubricate. I am definetly no expert on this subject but ATF is designed to work in conjunction with the torque convertor and clutch packs within the transmission to provice a hydraulic coupling to move the vehicle. This places the fluid under very high stresses and heat, etc. The fluid must perform under some extreme conditions. I know they use additives in the fluid to reduce sludge and varnish buildup as well as viscosity modifiers, pour point modifiers and additives to deal with oxidation, provide thermal/chemical stability, resist shear breakdown and anti-wear additives. This is in general of course, I'm not sure of the Mercedes formula. Either way, I just think that these types of additives break down and lose their effectiveness and lead to the buildup of deposits within the transmission as well as leading to a fluid that does not perform its duties as it should.
The advice of your technician to let your fluid be because it is used to it is probably the old rule of thumb that if it hasn't been changed in a long time just leave it alone due to new fluid dislodging the buildup that is already there and causing blocking of the fluid passageways within an automatic tranny or causing leaks etc.
Anyways, I guess its just personal preference when it comes to this type of thing and I admit, I am a bit paranoid when it comes to fluid life. My thing is that I can't tell you that changing the ATF will extend transmission life but I'm pretty sure it won't hurt transmission life.

[Rocky]

Yes and no.

If you keep a regular interval of fluid changes, it's alright. But if never changed it in awhile..it might lead to problems.

i.e. Older benz been using a thick grade of engine oil throughout it's..say 10 year life. One day the owner decides to put in a thinner grade. What happends? Oil leaks out the gaskets because throughout time, it was accustomed to holding in the thicker grade of oil. The engine was 'worn in' on thicker oil so thinnier oils might not be the best lubricant or do the job.

[Lost C280]

Rocky

Yeah, I get what you are saying. There is always that possibility of creating problems. For myself problems associated with dislodging deposits or causing leaks are what I would rather deal with than loss of anti-wear additives etc, and the consequences that may bring.

Again, it is all just personal preference....sort of choose your medicine I guess. I imagine its much like trying to do oil changes on an engine that has already been neglected for a long period of time. You can't reverse the damage that has already been done, no matter how many oil changes you do!!! Anyhow, thanks for the input and advice on all of this!!

[Metromoto202]

the 722.6 tranny is programed to adapt to fluid viscosity and drving patterns, don't change it. not too mention the price per quart.