I changed my transmision oil and filter last week for my 91 560SEC. It
took just over 7 liters to reach near the full mark. Drove the car for
about a week without a problem but now I noticed the shifting between 2
and 3 is hard and noisy sometimes very hard. Any idea on what could
have caused this?
Correct, when you fill it cold, it should be 10mm BELOW the low mark.
Drive the car until the trans oil reaches operating temperature and then check
it on a level surface
with the engine idling. You can let the sit and idle all day and night and the
trans will NEVER
reach operating temperature.
The manual says dry fill is 8 liters. I drained the oil in the pan and
removed it using 13 mm socket. Uscrewed the old filter, installed new
one. Put new gasket on the pan and torqued it up. Removing the oil from
the torque converter requires turning it until you access to the 5 mm
allen screw. I used flat head screw driver to turn the convertor
anti-clockwise. Most of the oil was here. I used genuine MB fluid.
Not sure what manual you used...... Mercedes says:
Initial charge: 7.3 liter [THAT is dry fill]
Following oil change: 6.2 liter [THAT is what you did]
And you never put in what it says it takes at once, you put in slightly less,
let it idle and check
it. Add as needed till it is below the add mark. Then drive it. ATF EXPANDS with
The new 772.9 7 speed transmissions are a nightmare to check the fluid level on.
Depending on the
shape of the oil pan, it depends on the EXACT temperature of the fluid. The temp
figure is 30C, 35C,
40C, or 45C depending on the shape. IF the temp is higher, we have to put a fan
on the trans to cool
it down and that could take up to 3 hours!! Try explaining that to a customer
who brings in the car
after Joe Independant just did him a favor by doing a fluid/filter change!!
This is the engineer in me talking: Wouldn't it be a good time to
construct your own temp. vs fill-level charts for higher temperatures?
You would then have to do this only once or twice after that to confirm
Might as well put those 3 hours to constructive use!
No, they do not have dipsticks. They have a tube sticking up in the pan. You
pull the drain plug and
if it is overfull, ATF runs out until the level is at the top of the tube.
What's that you say? How tough is that to figure out? You have to remember, ATF
has a high expansion
rate due to temperature. If the trans oil temp is too high, the level below the
top of the tube will
drop as the oil cools. And then you are under-filled!
The 722.9 transmissions are VERY sensitive to oil amount.
Thanks for the enlightenment. It's almost like they don't want normal
users to be checking their fluid levels, neccessitating a visit to the
deal...oh, wait! ;-)
Don't be too hard on Harri, he may be posting after a long hard day's
work (10:30pm EST), try posting at 2am in the morning, like I do
sometimes, and see how coherent I am. :D
Hi Martin: Anything wrong with not doing a complete change out of
fluid in the torque converter step (for those who change out the trany
fluid often enough). Furthermore if the fluid level after running and
cooling is exactly at the same place before and after a change of fluid
and filter, then one should be safe not to have over/under filled. I
use a small diameter push rod which measures the level when cold. Seems
like after 2-3 cycles (every 20,000 miles) ALL the fluid would be
It's better of course to drain it all and start with fresh new stuff.
The amount the torque convertor holds is significant. Still if you are
changing it "frequently", and it works ok, that's probably fine.
This means you need to drive the car without being sure it's correctly filled?
Not the approved method, but still if you baby it when you are feeling
out the fill level it should be ok.
Checking the transmission oil level should be done with the
engine/tranny HOT and after driving a bit with the engine still
Saeef, consider yourself lucky, last time I changed the trans fluid in
my 95 s300, I lost reverse! Got a bit better over time but slips real
bad on any incline and seems to grip better when cold. I'll do a full
rebuild when forward gears act up.....
Well, I decided to open the trans at a workshop. They found most clutch
plates worn out including the steel plates. The gear box has 15 clutch
plates, 5 are steel. The overhaul kit also includes all gaskets and
o-rigs. I just pick up the car from the workshop and it is shifting
very smooth. Thanks to all who provided me with feedback
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