we waist our time on oil we should be
 

we waist our time on oil we should be talking transmission fluid.

here we are driving mercedes benz with great engines and weak trannys.
and i believe one one these super atf's might help us.. does anyone have any suggestions... someone said redline works miracles...

Just did my tranny fluid change.
Used non-synthetic Castrol Dextron/Mercon III as suggested by Mercedes.

My idea is not to waste money on synthetic fluid but just buy a good brand ATF. However, changing the fluid every 30,000 miles is, in my opinion, more important that using an overpriced synthetic fluid.

My car is an 1988 300E.
If I had a newer model, say 2000 forwards, I would probably use a synthetic fluid and still change it every 30,000 miles.
ACM

Tip of the hat to ACM.

As pointed out by one participant here(jackd), synthetic is more profitable for the producers.

Plain ole oil and dexron changed on regular intervals will serve us well as it has for how many years?

I am not a synthetic oil user..it costs too much to change out more than 6 quarts every 3k miles.

However, since the transmission fluid stays in for 30k, the math is better..so I use mobil 1 in the transmission. I can't say the transmission works any better, but I am thinking that the synthetic keeps the temp a few degrees cooler.

We really don't seem to have transmission experts on this board. Come to think of it, any board

To each his own...I suppose it really depends on your driving habits and how much you want to protect your expensive engine and transmission. I learned years ago how fragile ATF can be when I towed a trailer with a 220S coupe on it for a few miles with a Chevy truck. I had just service the truck trans. After the tow I rechecked the ATF level and it was burned black. The ATF had overheated on the tow and was worthless. Quickly changed it and the trans seemed to be fine.

I think the synthetic is a good idea for transmissions, the numbers certainly pencil out better. The heat resistance of syn ATF is worth it in my book. As to engine oil, I also use M1 syn simply because I cannot afford unnecessary repairs.

The Ford Mercon V and GM Dexron III specs are very similar. The Ford spec is rated for a higher temperature so if your choose regular ATF, I'd get one certified for both Dexron III/Mercon V.

230/8

I am not an automatic transmission fan of any sort. I even have a manual in my 300E. I would not have bought one with an automatic.

That said, in order to understand how to keep an a/t alive you must understand what kills it. What kills it is HEAT! The normal operating temperature for ATF is about 170 degrees F. For every 10 degrees above that temperature the transmission fluid life is CUT IN HALF! In other words, if your normal atf change interval is 30,000 miles and your transmission fluid temp runs at 180 F instead of 170 F then you should be changing the fluid at 15,000 mile intervals. If the temp is 190 F then you should be changing it at 7,500 mile intervals and on and on.

Unless you are pulling a trailer in hot weather, or have other problems that cause overheating, you are probably not going above 170 F. Remember though, if you are running hotter engine temps it effects atf temp because the atf cooler is in the radiator.

For a/t it definitely pays to change it often, but in the case of an a/t, DON'T change it hot or you'll get burned.

Good luck,

Wait a minute... My '97 S500 manual says it has a lifetime fill! Thery're right. The fluid will last exactly as long as the transmission! In my car's world, that means about 120K per transmission/oil change. :)
Actually, since this policy is so rediculus, by the time you buy one of these cars with 80 or 90 thousand miles on the meter, the fluid is well on it's way to oblivion. I change mine every 25K in hopes I can nurse it along until about 180K. (car has 101K now)

I never changed my ATF in my 1984 300D, only my oil. Never had a problem in 20 years 211,000.
My 1997 ford truck has 191,000 I don't even know where to check it.

RE: the 300D
I wonder if it has anything to do with the amount of power the 300D made. My S500 is pretty fast considering it wieghs 2 tons. The thing generates a bunch of heat. MB gets a C- in late model transmissions.

I read somewhere about a guy who is one of the few ZF authorized transmission service shops in the US. He said if everyone changed the Trans fluid every 15000 miles and fluid and filter every 30,000 miles that he would be out of business. I change every 30,000 miles.

This lifetime fluid is crazy but MB expects you to buy a new one and junk the one with 120,000 miles on it. Most manufacturers want their car in the scrap heap so they can sell a new one. They also make the repairs, parts and assemblies so expensive that it doesn’t pay to fix one, so they can sell more cars. One of my mechanics told me his first day at a GM dealer; they told him his main job is to sell new cars. He was supposed to find so many expensive repairs that the customer will trade it on a new one.

As a general rule I believe the statement about 15,000 mile ATF changes making the transmission last forever, well so to speak.

On a Benz this is easy to do. There is a drain plug on the trans and the converter. On most late model domestic cars you can't drain the converter at all and you have to pull the pan to drain the fluid. That means if you change the fluid, you are only draining about half of it. BAD, Bad, bad....

Yes there are some transmissions in low powered cars that aren't driven very much in hot weather except on the highway that can go a long way with the same fluid, but those are the exception.

My solution, just drive a manual transmission and put a clutch in it every few hundred thousand miles.

Have a great day,

I am changing my trany oil every 25k-30k but as I was reading thru the posts I am thinking to shorten the interval to 20k. The question is, by changing just the pan oil (about 2qt ) in the middle of the interval, will be a good ideea?
I am using Mercedes synthetic fluid despite the fact that is a 733.434 trany, but I did see an improvement....so I will continue using it. Car has now 194k and the trany is perfect.

If you're able to drain both the converter and pan on your MB, then do so. I'm not sure what benefit you'll gain by merely replacing just 2 qts. of new into x amount of used?

If your vehicle does not not have a converter drain plug, then you drain what you can or gamble on a flush which can break sediment loose. When that happens, you can loose an expensive transmission.

I have yet to see an MB automatic that does not have drain plugs on the converter. It has several so it makes it easier to get one of them in position to drain.

Doing a drain and fill of both transmission and converter and then changing the filter every other drain should work fine.

Your driving conditions will radically effect your drain interval. If you drive alot of stoplight to stoplight, especially in hot weather, then change it more often.

Good luck,

After my B2 piston failure I just change it every spring regardless of mileage with dino. The summers in NY are brutal when you factor in the traffic too. I bought jackstands, absorbent mat and a hydraulic jack and I do it in my driveway. It take 30 minutes tops. The hardest part is getting that damn torque conv. drain plug aligned :)