No Automatic Transmission Dipstick?!?
 

My '96 SL600 has developed a small AT fluid leak. So I went to check the AT fluid level… lo and behold, there is no AT dipstick – just a silly MB cap that says dealer serviceable only.

Question – Without a dipstick, how does one check the level of the AT fluid?

Cheers,
Jeff

You gotta buy the dipstick from the dealer, or have someone with the dipstick check it.

It is a shop "tool".

Search here and you can find the dimensions of the end of the stick and then make your own from heavy wire or from a junk yard donor.

My 1996 E320 model still has the dip stick. Even that the level checking is complicated.

The dipstick had two marks, actually four, Max and Min for AT fluid temp at 80F (30C on mine) and Max & Min for 180F (80C), measured at the AT pan.

I don't know how the hell can it be achieved? how do you catch the moment of 80F and 180F, it is just crazy that the engineers came up with that.

The SL more than likely has the 722.6 trans and the E the 722.4.

SDS tells you internal fluid temp.

Previously dipsticks measured the distance from the top of the tube to the fluid level. The new transmissions measure the depth of the fluid by using a stick that is considerably longer than the distance to the bottom of the pan. What you then are measuring is the distance from the bottom of the pan to the surface of the fluid or the depth. Such a dipstick will not fit installed into the tube and as such is a tool rather than part of the car.

Most manufacturers have become ultra sensitive to the exact level of the fluid in the trans. This has to then include measuring it at a specific temperature. While this is easy to do using the diagnostic computer it is also easy enough to do with a Raytek infrared temp measuring tool http://www.flw.com/rayt_ol1.htm?gclid=CJejifGA75ECFQZzHgod-G9Spg

There are other cheaper versions out that are probably accurate enough for these measurements.

[Sigh] the uncomplicated time with my old 1989 300CE is gone. Two level measures at two specific moments when the AT fluid reaches the specified temperature. Supposed you have AT fluid temp over one range, say 120F, what do you do? wait and re-measure again and again until it cools down to 80F?

And if one level is OK and the other not, should the fluid be added or extracted? either way it will affect the good one.

My expensive approach: I took it to my indy, got it flushed and refilled and hope that it is OK. I can't never be sure :o.

Many cars have two ranges on the dipstick: one for "Hot" and one for "Cold".

If you're more comfortable with that scale, then 180F = Hot, 80F = Cold.:D