Merc Auto Box Lifetime ????

41Stan41

Hi
I have a 07 C 180 Merc with an automatic gearbox , it has just over 130,000 KM on the clock which is real milage as i have the car from new.
I have a few questions if anybody has the time to answer .

Firstly does an auto have a clutch of some type as recently(past few months) i have noticed very slight differences in the changes , both up and down the gears .
They are very slight as no one else has noticed ,even my son has not said anything and he is into his cars and has driven mine on a few occasions.
The car has had all services and one before last was gearbox service with no problems they said .

Secondly what is the expected lifetime of an auto gearbox ??
It has not been treated badly or raced around the place .
As i said changes are very slight and i was wondering if its my imagination or not ,by the way it was recently serviced and i said nothing to see if they would notice anything when it was taken for a test drive after service and nothing said to me ,told all was good .

So any info would be appreciated .

Thanks

jayok

I am sure that the autobox has a lifetime, but 130KKm is very little on this.


Normally, the gearbox fluid will breakdown overtime and should be replaced. When the fluid breaks down, stiffer and slower shifting can occur as well as delays changing gears, etc. You mentioned that you had the box serviced recently and that they found no issue, I assume that the fluid and filters were changed for it? If they were, did they use the exact specification of gearbox oil? If not you could have issues.

Oh and not sure if Mercs have this "sealed for life" policy that BMW have/had. Either way, ignore it and get the fluid changed.

hi5

Yes, traditional automatic gearboxes have lots of small clutches and eventually they wear out, check the fluid, if it looks a little darker than normal and has a burnt smell then the clutches may be on the way out.

v240gltse

hi

@jayok: you beat me to it suggesting getting the tranny fluid changed.

1. @41stan41 make sure that the garage used the correct type of mercedes fluid ( expensive but i feel its worth it on such a critical part ) and filter.

I had a similar issue and a tranny fluid change cured the issue

regards

brendan

sumo12

v240gltse wrote: »

hi

@jayok: you beat me to it suggesting getting the tranny fluid changed.

1. @41stan41 make sure that the garage used the correct type of mercedes fluid ( expensive but i feel its worth it on such a critical part ) and filter.

I had a similar issue and a tranny fluid change cured the issue

regards

brendan

+1
I think that model has the 722.6 transmission which originally was designated as "sealed for life". That's crap - drop the transmission sump pan, change the filter and flush out as much fluid as you can (difficult to drain the torque converter as there is no drain plug on it) and replace with good quality ATF, preferably MB fluid. There are 3 different levels of MB fluid, buy the best one you can afford. I can give you part numbers if you need - make sure the level is perfect when completed otherwise you will cause irreversible damage to the transmission.

If you don't want to do this yourself, MB dealer or good merc independent will do this all for you. Should cost you approx €80 for fluid, filter is €30, sump gasket €30 (best to replace but not vital) I think and maybe an hours labour?

If you need any further help just shout. I'd say this will sort your gear change out, those transmissions are pretty good and hard to break. That is a high torque transmission, it features in a lot of models, right up to 6.0 because it can handle the torque, your 1.8 won't be overloading it!

Sumo

cadaliac

jayok wrote: »

I am sure that the autobox has a lifetime, but 130KKm is very little on this.


Normally, the gearbox fluid will breakdown overtime and should be replaced. When the fluid breaks down, stiffer and slower shifting can occur as well as delays changing gears, etc. You mentioned that you had the box serviced recently and that they found no issue, I assume that the fluid and filters were changed for it? If they were, did they use the exact specification of gearbox oil? If not you could have issues.

Oh and not sure if Mercs have this "sealed for life" policy that BMW have/had. Either way, ignore it and get the fluid changed.

+1
The gearbox also has an ecu of its own and will adjust the bite point of some gears afaik. Same as when the car is cold, it holds on to first for longer. As mentioned above, oil breakdown and clutch wear will adjust the bite point.
133k km's is nothing on a good autobox. Check the manual for service interval and if the box oil should be changed or not. Either way, I would change the box oil if it got jerky or sloppy, but i wouldn't bother if the bite points have just changed slightly. That's normal enough wear and tear.