Hi all,

Just something I have noticed whilst driving my W210 E300 Turbodiesel around today, in the morning when the transmission is cold I have noticed that there isn't much lag in throttle response with regards to the car moving away from stationary.

Then after a fair few motorway miles (I am loving the cruise control/limiter btw!) I find that its slightly slower off the mark.

My guess is that the fluid in the torque converter when cold is thicker and therefore the turbine and impeller have a slightly stronger coupling vs a thinner hotter fluid.

Just wondering if the slight reduction in responsiveness when up to temperature could point to me needing to swap out the fluid - please note that the car shifts fine in all gears + overdrive, it does sometimes jolts slightly when coming to a stop though.

The car does have a transmission cooler as standard, however much like other parts on the car I am not sure 100% if its working correctly - currently in the process of fixing all previous owner's bodges etc.

Just wondering what everyone else's thoughts are on the matter, I am aware that the transmission is 'sealed for life' meaning that Mercedes will get more money when the transmission fails due to the oil breaking down in the future.

I have noticed that the oil dipstick tube is the same as the engine oil dipstick tube with regards to size, so I can simply use a suction device and remove the old oil and replace it with the correct oil (aware the oil isn't cheap).

Thanks in advance!

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UK spec Mercedes W210 E300 Turbodiesel wagon - OM606.962 with 722.6 transmission - rust free!

Hard shifts and tighter converter are normal at ambient temp. Nevertheless, swapping fluid and filter is something I always do when a used vehicle shows up in our stable. Even did it with the black graphite- impregnated expensive MBz stuff. Rear end fluid also.

Thanks for the info, this is my first car with an autobox in so never too sure how they usually behave. I noticed that the cap on the gearbox dipstick tube has a red tab, I believe these are black from the factory so it looks like its been changed before.

Will definatly look at changing over the diff oil as I don't know when that was done, I don't have any service history on this car, however as even the new looking clear fuel lines have Mercedes all over them I am sure its been done as per specs.

Might look to upgrade the valve body/change to blue top solenoids/check the shifter springs if I am dropping the pan etc. Would it be worth me changing the fluid via a vacuum system rather than dropping the pan?

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UK spec Mercedes W210 E300 Turbodiesel wagon - OM606.962 with 722.6 transmission - rust free!

The 722.6 can give a bump when down shifting coming to a stop. This is caused by the torque converter clutch dragging. At light throttle when driving, the dragging TCC can cause a vibration like driving over rumble strips. ( This is torsional vibration and feels like a manual shift in too high a gear. ) The dragging can get bad enough that the motor will stall when a gear is selected. There are rebuilt converters that use springs / rubber tabs to overcome the problem.

Have a look at the Sonnax 722.6 - Sonnax and Superior Superior Transmission Parts transmission aftermarket valve body fix it kits.

These trans use synthetic oil that apparently suspends clutch particles rather than letting them settle out. I've taken some high mile never a fluid change units apart that had zero clutch material in the pan, not even a coating. I'd say the chances of MB seeing these trans for an out of warranty is pretty small and doubt they are going to damage their reputation for a small short term gain. Sure there are going to be early failures but not in the numbers that make any sort of business sense.

The biggest issue on early units is the bushing between the input and output shaft. Depending on the weight of the car and time spent in lower gears, this brass bushing wears allowing the shafts and planetary to run off center. This allows needle bearings to come out of a cage and fall into the gears damaging them.

Keeping to my "lifeing" of parts to avoid unannounced breakdowns, I'm rebuild the trans in Moms 97 C280 that has ~ 165 K miles before it fails. This bushing is slightly worn and needs replaced but no gears are damaged. The clutches are fine, no material is in the pan, still has original filter.

A 98 S320 ~ 150 K miles trans I took apart had the bushing worn paper thin and gear damage. While there was metal in the pan, there is no sign of clutch material and the fluid looked good.

There is a drain plug in the bottom of the trans pan, this may work better than a suction device.

If you could test for same with an engine with the normal operating (warmed-up) temperature versus cold transmission, then you may have something to your symptoms of harder shifting when cold.