Re-Filling the 722.6 Transmission
 

Gentelmen

I understand the 722.6 trans is very sensitive to fluid level.

Can any one tell me what that means. I believe Im overfilled and the trans neutrals out after getting up to about 20 MPH. This is in a 1996 SL600

How do I use the special dipstick tool. I received no directions with mine. The picture is as far down as it will go. Does that look right. If I put it in as far down as it will go as shown in the picture and the fluid level is above the high temp highest mark after limping it around the block one time.

This transmission was completely drained including the TC. There are approximately 9.25 new qts of fluid in it and it appears to be about 3/4" over filled. Might this explain a neutral out condition.

Overfilling can damage your transmission. I would not drive the car until draining some of the fluid.

There are two ranges on the tip of the tool. Each has a min and max mark. The lower one (farthest from handle) is the level at 25C or ambient temp. The upper one is the correct level at 80C (operating temp of trans NOT the 80C coolant temp gauge on dash).

To measure insert the tool until you feel the tip reach the bottom of the sump. Don't push so hard that you flex the plastic tip. There may be a slight restriction as you insert the tool before reaching the sump.There should be about 6-8" of the tool sticking out of the tube when properly inserted.

ASAP drain some fluid out until the level is in the 25C range (cold transmission). Drive the car for about 20-30 min preferrably on uneven terrain to ensure the transmission has reached full operating temp. I like to run it thru the gears manually but I don't think that is necessary especially since you've already driven the car.

Park the car on a level spot. Wait a couple of minutes for any draining. Check level. Add new fluid (a small amount at a time) as necessary to reach the upper range. Good luck.

Thank you that is kind of what I figured but when I first got the tool I was expecting the red handle to seat in the tube. So where I have it in the picture is about where the tip just touches the bottom of the pan. Draining right now.

The "tool" is designed to fit multiple engine and chassis configurations. You only use as much stick as is needed to feel its tip hit the bottom of the pan.

Helps to mark that point once you find it so you know when you are getting close.

Engine running of course.

The fill for your trans should be in your OM. They do vary. IIRC, my diesel with the 722.608 took 7.2L when I refilled it. This was ~.2 L more than I drained.