99 CLK430 tranny fluid check
 

I am wanting to check the transmission fluid in my Benz. I found a dipstick at the back of the engine but the cap says MB Shop ONLY. It is a round cap with a retangle tab on it. How do I open this and is this what I want to do to check the fluid level and even suck out the fluid from??

There is no dipstick in the tube. In order to check the fluid level, the proper temp has to be checked with SDS or an HHT and the shop dipstick tool has to be used to verify the correct level when the trans fluid is at the correct temp. You will also need a new plastic cap lock to resecure the dipstick cap after it is removed.

This is done because checking the proper fluid level at the correct temp is very critical in these transmissions.

If the trans has never been opened and it is not leaking, the level in there should be correct. Why are you wanting to check the fluid level, is there a leak, or do you want to perform a fluid change?

Yes I was thinking about changing the fluid and filter.

If you change the fluid make sure you use only the approved fluid from MB in the 722.6 tranny. You will need to get a dipstick tool to check the level and make sure you check the level while it is at the proper trans temp. The tranny also has a drain plug on the torque converter, so you will be able to get just about all the fluid out.

I think it takes around 9 quarts or so for a complete change.

Check out the "DIY" tech article posted on this site... I did a tranny fluid change on my 97 C230 [722.6 tranny] You'll need a "dipstick tool" , MB tranny fluid,[ avail via Fastlane] infrared thermoter [to measure temp of tranny fluid]... not a real difficult job.