anghrist

Hey folks. Considering this for my W210, but edgy about maintaining the reliability of my car.

Green E300-DT,

You said that your tranny went south soon after this upgrade. My car has about 122k on it currently and I did just have the tranny flushed and filter/fluid changed. Any chance that these preventative measures every 60k miles will make a difference in transmission longevity??

uberwgn

My car has been chipped for a few years - - no concerns whatsoever. Transmission is serviced, not neglected.

Green E-300 DT

I guess anytime you up the power, you may loose longivity.

The only car that I ever modified where the extra power did not harm the trans was my TDI.
I figured that the torque was increased by at least 75 percent.
I never heard of anyone having any problems with their TDI automatics,
and many ran their cars with even more power that I had.
One fellow regularly used his car as a rolling lab for his engine
modifications, and went to the drags quite often.

I believe my '99 E-300 DT did have approximately 20K miles
with the modified chip before the tranny failed.
Sorry, but I cannot find my exact records at this time.

HTHs

uberwgn

I totally agree, D. Ask for more out of a machine and you're gonna pay the price somewhere else. However, if you look at the torque rating of the transmsission, there is still quite a reserve when compared to the increased torque output of a chipped engine...at least what I've seen here in the USofA.

Green E-300 DT

There were two trannies listed back in '99 for the W-210s:

The weaker one for the E-320s and

The stronger one for the E-300 DTs and the gasser V8.

These have model numbers indicating their respective torque capabilities expressed in nm.

The diesel was supposed to have the stronger transmission, or so I was told.

Now, whether this was indeed true or not, I cannot say.

Having said that, I do not feel that the extra torque after chipping would
be a problem if the diesels indeed came with the stronger trans?

Perhaps somewhere over 127K miles is at or near the life of this transmission?

My son-in-laws '97 E-420 has that many miles on it, and it is almost 10 years old and has
never had tranny service and has been used mostly in the metro area of Los Angeles.

Who is to say that my car was not abused prior to me getting it at 82K miles?

There was evidence that the engine oil had not been serviced regularly.
(Uneven leakdown pressures, etc. Clogged rings perhaps?)
However, this problem cleared up with regular synthetic oil changes ( Delvac 1, Amsoil ) and the
more miles it accumulated, the smoother the idle became and the stronger it ran.

What is the expect life of these trannies under normal useage?

uberwgn

D, my confidence is high that the chip did not directly cause the trans to fail in your car. I strongly believe it was related to the lack of routine service required by any auto trans. It's my experiencing that the 5 spd auto gearbox in these cars is actually quite good. Lifetime? Dunno, perhaps 200k miles is approaching the limit even for a trans that's serviced.

Green E-300 DT

I've tried to get the s-i-l to change his tranny fluid and filter, but he's not into
cars at all, and doesn't really understand the need to have it changed.

I have a question:

Do you think that using the "W" mode most of the time can harm these transmissions?

Mine did not like the higher ratio when backing up my slightly inclined driveway, so I would
always throw the switch back to "S" before putting the lever in reverse.
You must do that first as the change will not happen once the reverse gear is engaged,
unlike when in drive. When in drive, one can actually feel the tranny shift back
from second to first when that switch is thrown.

I would use the "W" position most of the time except when I felt that I needed the extra
acceleration provided with that lower gear, or when the start was an uphill incline.
The extra torque, especially after it was chipped made first gear unnecessary most of the time.

The s-i-ls E-420 seems to have plenty of torque stock to take off from rest in
second gear, even though it has taller gears (2.82s) than the diesels' 3.07s.

So can a person harm the transmission by using the "W" position most of the time?

In either first or second gear, a person will be right into the beginning of
that fat torque curve just as soon as the car is beginning to move.

Another question:

How dependable is the 7-G transmission in the Bluetec cars, especially after it has been chipped?

Thanks