Check the automatic transmission fluid level

1986-1995 : 200TD, 200CE, E200, 260E, 300E 2.6, 300E 2.8, 300E, E320, 400E, E420, 500E, E500, 300CE, E320, 230TE, 300TE, 300D 2.5 TURBO, E300 DIESEL, 300TD, 300E 4MATIC, 300TE 4MATIC, E36 AMG
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dhaigh
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Joined: Fri 12 Aug, 2016 3:05 pm
Model you own: w124
Location: Melbourne, Australia
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Check the automatic transmission fluid level

Post by dhaigh » Sun 13 Aug, 2017 6:51 pm

As most of you will be aware, the level of the automatic transmission fluid is important to the correct functioning of the auto transmission.
So checking it correctly is important. What some people don't realise is that the fluid level changes with the temperature of the transmission fluid.
How much this varies became apparent to me when I checked the fluid level on my 1988 300CE recently.
I knew the car should be at normal operating temperature, so I drove it around the block before checking it (on level ground, selector in P and engine running). The fluid level was at the bottom MIN mark, so knowing that there is 300ml between the MIN mark and MAX mark, I was about to put in the required amount of ATF when I read my Haynes Maintenance Manual which stated that the car should be driven for at least 15 Kms before checking. On reflection this makes sense, because although the coolant may be at 80C, the transmission will not get to 80C until much later.
So I drove the requisite 15 Kms and checked the level again, and lo and behold the fluid level had come up to the MAX mark - perfect!!
It's important to realise that it's just as bad for your transmission to be under the MIN mark as it is to be over the MAX mark - so lesson learned!!
For the pundits that like reading the Mercedes maintenance manuals for this, here is the link to the Mercedes manual for checking and correcting the automatic transmission fluid level for the W124 model (as well as W123, W126, W140, W201, R107 and R129 models). It is advisable to know what engine and transmission you have before reading these maintenance manuals - for the 1988 300CE it is M103.9 engine and 722.3 transmission.
http://www.w124performance.com/service/ ... 1/2710.pdf

The maintenance manual (above) is one of over 80 maintenance jobs for which manuals are available. Here is a link to the complete list of jobs for the W124 model up to 1993 - the check auto transmission fluid level is item 2710 in that list.
http://w124-zone.com/downloads/MB%20CD/ ... e81-93.htm

Happy reading!!
1988 300CE Coupe
Departed:
1989 300E
1990 MX5
1966 Ford Fairmont
1954 Healey BN1
1972 E-Type V12
etc
See my website: http://myclassiccars1967to2017.blogspot.com.au/ for the complete list!

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MMWA
450 SEL 6.9
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Joined: Sun 08 Dec, 2013 2:23 pm
Model you own: I own multiple different models
Location: Perth

Re: Check the automatic transmission fluid level

Post by MMWA » Mon 14 Aug, 2017 7:27 pm

yep, i've filled my trans to max, just letting engine reach 80c and not even driving it - ended up about 3cm over the max mark after going for a drive.... FAIL.

I know better now, having worked on ZF transmissions with no dipstick and just a hole in the pan.

after following the procedure of selecting gears etc, Infrared thermometer pointing at the pan, so you know its 80c top up with pump bottle till just starts to leak out then insert plug. Job done. short window of opportunity, timing is critical as after certain temp you have to abort and wait for a cool down and try again.
MMWA

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dhaigh
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Re: Check the automatic transmission fluid level

Post by dhaigh » Tue 15 Aug, 2017 9:18 pm

MercMad West Australian wrote:yep, i've filled my trans to max, just letting engine reach 80c and not even driving it - ended up about 3cm over the max mark after going for a drive.... FAIL.

I know better now, having worked on ZF transmissions with no dipstick and just a hole in the pan.

after following the procedure of selecting gears etc, Infrared thermometer pointing at the pan, so you know its 80c top up with pump bottle till just starts to leak out then insert plug. Job done. short window of opportunity, timing is critical as after certain temp you have to abort and wait for a cool down and try again.
Yes. If you read the first of the 2 links in the original post, the Maintenance Manual for the different transmissions of the W124 actually gives the measurement on the dipstick when the fluid is cold (20-30C) as well as at normal operating temperature (80C).
So it is theoretically possible to check the transmission when it is cold (measurement should be below the MIN) and when it is hot (measurement should be no higher than MAX), although I would always prefer to do it after a 15kms drive, when the transmission fluid is at 80C.
1988 300CE Coupe
Departed:
1989 300E
1990 MX5
1966 Ford Fairmont
1954 Healey BN1
1972 E-Type V12
etc
See my website: http://myclassiccars1967to2017.blogspot.com.au/ for the complete list!

bberni
Pagoda
Posts: 125
Joined: Thu 04 Jan, 2007 11:53 am
Model you own: w124
Location: Fernvale Qld

Re: Check the automatic transmission fluid level

Post by bberni » Wed 28 Feb, 2018 7:45 pm

soplease what FAIL details if the tranny is beyond MAX?
only refilled mine twice when it hesitated to switch down when cold - to a lower gear?!
I can translate to /from German for you. von DeutSchland!

bberni
Pagoda
Posts: 125
Joined: Thu 04 Jan, 2007 11:53 am
Model you own: w124
Location: Fernvale Qld

Re: Check the automatic transmission fluid level

Post by bberni » Wed 28 Feb, 2018 7:48 pm

so please what FAIL details, if the tranny is beyond MAX?
only refilled mine twice when it hesitated to switch down when cold - to a lower gear?! in 8.5 years after 140,000kms now on 303,ooo kms now...smooth as!
for sale too...
I can translate to /from German for you. von DeutSchland!

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dhaigh
C Class
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Model you own: w124
Location: Melbourne, Australia
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Re: Check the automatic transmission fluid level

Post by dhaigh » Thu 15 Mar, 2018 7:45 pm

bberni wrote:
Wed 28 Feb, 2018 7:45 pm
soplease what FAIL details if the tranny is beyond MAX?
only refilled mine twice when it hesitated to switch down when cold - to a lower gear?!
My understanding when the trans is filled above the MAX mark, is it can cause the trans fluid to start frothing and puts additional strain on the trans.
You can remove excess fluid with a tube inserted in the filler hole and a pump to suck the excess fluid out.
1988 300CE Coupe
Departed:
1989 300E
1990 MX5
1966 Ford Fairmont
1954 Healey BN1
1972 E-Type V12
etc
See my website: http://myclassiccars1967to2017.blogspot.com.au/ for the complete list!

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Ivanerrol
Mercedes Demigod
Posts: 5782
Joined: Sat 12 May, 2007 3:21 pm
Model you own: w204
Location: Melbourne

Re: Check the automatic transmission fluid level

Post by Ivanerrol » Fri 16 Mar, 2018 11:28 pm

Just another reason for the DIYer shade tree mechanic to invest in a laser temperature sensor device.

Point it at the sump to measure the temp is at 80 degrees before taking the level on the dipstick.
This is the method approved for 722.6's - backwards compatible for earlier tranny's
W211 - E240
W204 - C280
Departed
W202 - C200, C180, C180
W126 - 380SE , 380SE (Ex SA Import), 560SEL
W124 - 300e, 260e (ex Japan)
W111 220s (Indonesia) 4 speed manual column shift
W123 230
W116 450SEL
W140 420SEL
W210 E240, E240
W209 CLK 240
W201 190e 2.6 (ex U.K.)

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