I replaced the pin connector with the two o-rings on the 722.6 automatic transmission due to leak. (1999 ML 320 with 141K miles) I think I lost less than a 1/4 of a quart when I removed old connector. I have the dipstick with the 80 degree C range and 25 degree C range to check the fluid level. I added 1/4 quart of fluid.

My Alldata DIY says to check transmission fluid level with the engine running. When I do that it seems I am low on fluid. Or in the alternative I'm not reading to the dipstick right. If I wait 2 minute after I shut off engine the reading is right in the 80 degree C zone.

I’m not inclined to add more fluid. Concerned that overfill will cause harm. Vehicle shifts and drives fine. The leak I had resulted in very little fluid loss. I've know about it for a few years and have monitored it.

Not really sure what to do. Any advise?

Ron,

Check the ATF:
1.Engine running
2.ATF at Operating Temperature (30 minute drive in town)
3.ON Level Ground (I'm a Nut,I've got a spot that I've checked with a 4 Ft.Level)
4.Just before you pull the dipstick...run the shift lever all the way through all the gears,with your foot on the brake
(Remaining in each gear long enough for it to Engage) and end up at PARK.
A Gnat's hair below the HOT marking on the stick is Good!

With the engine running the Tranny's pump is circulating fluid throughout the
whole Transmission System (Cooler,Valve Body,Torque Converter. Etc.) AND
MB has the "Stick" marked for as close to operating conditions as possible.
(Thank God, We are not required to "Check the Fluid" with the Tranny in Gear
at road speed on a Dynamometer...THAT would be the CORRECT way as far
as the engineers are concerned...The Lawyers won't allow that for Liability
reasons)

When you're checking it with the engine ON...
How far below the 80 C mark is the fluid?
[EDIT:HFB the "HOT" mark is The fluid?]
What percentage of the distance between the HOT and COLD marks is the
level shy?

AND YES you're completely correct...Better a smidgen low than OverFill.

Owners with lots of Germanic Heritage are alleged to have been observed
Adding and Subtracting ATF with an Eyedropper and their MityVac (through
the DipStickTube)until the level's perfect.

__________________
'84 300SD sold
124.128

Well I can not really tell for sure where or if at all the level is on the dipstick with the engine running. I changed the fluid about 23K miles ago and it’s still rather clean, looks relatively clear on dipstick.
I will try to check the level following the your instructions tomorrow.

Also how do you determine temp is 80 degrees C.? Just because the temp gauge of coolant says 80 degrees I do not think that means ATF fluid is 80 degrees C. I used my infrared thermometer and took temperature reading off ATF oil pan. Temp was only 65 or so degrees C even after driving. I think the ambient temp is about 60 degrees F.

STAR Diagnosis System.

__________________
1973 280SE 4.5 (Sold)
1984 LWB 280GE (Sold)
2000 G500 NMLE - "Deep Throat"
2007 ML320 CDI (Sold)
2010 Porsche Cayenne S Transsyberia TipTronic (Sold)
2010 Audi Q7 3.0 TDI (Sold and Sorely Missed)
2014 ML350 BTC
2015 Audi Q7 3.0 TDI (On Order)

Would normal operating temperature not be sufficient? Isn't this the temperature at which the vehicle will normally be operating? Drive around for 30 minutes and park on even surface at idle check fluid. This worked fine for me - truck shifts great.

Don't you think you are over analyzing this? The engineers at MB would certainly be satisfied by you checking the trans fluid at normal operating temperature unless of course you intend to drive in an extreme environment. ;-)

Also, suggest you change the trans fluid from old fluid type to new type p/n 011-989-45-03-13 (ATF 3353) and change filter. Since doing this my truck 00' 320, shifts more smoothly and predictably. NOTE: Once you goto this new fluid type you can't go back to old type.

Good luck!

"Normal Operating Temperature" is close. MB's engineers in the WIS state to measure it with the STAR Diagnosis System. I've done it both ways; and N-O-T is pretty close.

Fwiw, the newest ATF is now ATF 134, P/N: A.001.989.68.03.10 for the 1 liter bottles.

__________________
1973 280SE 4.5 (Sold)
1984 LWB 280GE (Sold)
2000 G500 NMLE - "Deep Throat"
2007 ML320 CDI (Sold)
2010 Porsche Cayenne S Transsyberia TipTronic (Sold)
2010 Audi Q7 3.0 TDI (Sold and Sorely Missed)
2014 ML350 BTC
2015 Audi Q7 3.0 TDI (On Order)

i stand corrected... copied wrong trans fluid p/n
tks Dutch for keeping me honest.

So...just a curious question, if the trans isn't up to the 80C after driving for a while - what to do to increase the temp? Sterno under the trans pan?

The 80 C figure I used was in reference to the Engine's Normal Operating Temp.
(I assume if the Engine is Warm enough>the Tranny's warm enough.)
That's why the suggestions are for driving around for 30 minutes or so, to insure
Everything's toasty warm and ready to be measured.

Hey, I'm so sorry.BUT, even I, ain't gonna stick a Temp Probe into the Tranny
Dipstick Tube.

The Engineer's intent in the markings on the dipstick was to apply measurement
as close as possible to operating conditions.'Given the expansion of ATF with
heat,the correct measurement scenario is with a Tranny @ Operating Temperature.

Thank you So Very Much,
for pointing out the Error of my ways.

__________________
'84 300SD sold
124.128

The use of the STAR Diagnosis System does not entail sticking a temperature probe down the dipstick tube. There's an internal electronic sensor to measure temperature built into the tranny; and it's read out with the STAR through the OBDII connector.

Normal Operating Temperature may or may not be the correct temperature to measure the ATF level, although on the 5-speed it probably is.

As an example of it not being the correct temperature, witness the new 7G-Tronic. On it the measuring temperature is 40°C. That's only slightly above room temperature and way below N-O-T. On that one, you're gonna have to have a proper way to actually measure the temperature, if you want to get it right. Ask me how I know.

__________________
1973 280SE 4.5 (Sold)
1984 LWB 280GE (Sold)
2000 G500 NMLE - "Deep Throat"
2007 ML320 CDI (Sold)
2010 Porsche Cayenne S Transsyberia TipTronic (Sold)
2010 Audi Q7 3.0 TDI (Sold and Sorely Missed)
2014 ML350 BTC
2015 Audi Q7 3.0 TDI (On Order)

My 1999 ML 320 has the 5 speed automatic. I drove it on the highway for about 20 mins. Parked with the engine running, waited 2 minutes and took a reading, engine still running, with the special dipstick tool. The level was 1 mm into the 80 degree C range.

Hopefully that will be good close enough. The ambient temperature was 55 degree F. I'm thinking if it was warmer outside the level might have been a little higher due to expansion. I did use my infrared thermometer and the bottom of the oil pain was about 76 degrees C.

Dutch,

Will they go to almost any lengths to force you to take it to the Dealer?

Ron,

You're gonna shoot me....BUT,I swear I'd slide the MityVac's hose down the
Transmission dipstick tube and "Slurp" a smidgen out.You're right, it'll rise
this Spring (Which might be Tomorrow,around here) with the Ambient UpTemp.
That way you don't have to "Mess with it".

__________________
'84 300SD sold
124.128

I'll keep an eye on the level. I'll check when ambient is higher and for sure in summer when it gets to about 100 F.

I didn't take my G500 (5-speed w/dip stick tube) to a dealer, nor did I take my ML320CDI (7-speed w/no dip stick tube) to the dealer.

PS - That drain and fill from below on the 7G-Tronic pretty much (but not completely ) eliminates any shade tree mechanic from changing or checking the ATF.

__________________
1973 280SE 4.5 (Sold)
1984 LWB 280GE (Sold)
2000 G500 NMLE - "Deep Throat"
2007 ML320 CDI (Sold)
2010 Porsche Cayenne S Transsyberia TipTronic (Sold)
2010 Audi Q7 3.0 TDI (Sold and Sorely Missed)
2014 ML350 BTC
2015 Audi Q7 3.0 TDI (On Order)