Date registered: Apr 2005
Vehicle: 2002 CLK430
Location: Southern California
Mentioned: 2 Post(s)
Quoted: 3 Post(s)
It seems to me that Mercedes-Benz didnâ€™t include a dipstick because they felt it would result in the average owner or corner mechanic doing more harm than good. When adding fluid, the fluid level is supposed to be checked at two temperatures. Low fluid can cause funky shifting. MB service doc 27A95105 has details, but in a nutshell, low fluid allows air bubbles to form. On the other end of the spectrum, overfilling will damage the transmission. This is why *I think* it has no dipstick; Jiffy Lube type â€śtechsâ€ť top off everything.
The question is, why would someone have to regularly check ATF levels? Fluid doesnâ€™t evaporate. Unlike motor oil, it doesnâ€™t burn. That leaves a leak as the only way for a 722.6 transmission to get low on fluid. With normal maintenance, most leaks are detected. Unfortunately, many people claim all those checks that are performed during routine services are unnecessary. Without checking, leaks go undetected.
If I were you, Iâ€™d check it for leaks and dump the codes. The original equipment transmission harness plug adapter has an o-ring that has been known to go bad. If the plug adapter on your car is wet, you could just replace the o-ring. A new harness plug adapter is less than $10, and the upgraded o-ring is $2. I had my local dealer change them both on my car. Mine wasnâ€™t leaking, this was preventative maintenance. The new style o-ring is a one time fix, as its new design allegedly wonâ€™t leak in the future. While fixing the leak, Iâ€™d recommend changing the fluid and filter, and having them set the adaptation.
If the plug adapter leaks and someone ignores the wet spot on the garage floor, the ATF could wick up the wiring harness to the TCU. At that point, someone may recommend a new $300 wiring harness, the plug adapter, and new o-rings. I donâ€™t know whether theyâ€™ll recommend cleaning the wet card in the TCU, or replacing it.
Dumping the codes will tell you if an electronic malady (such as a bad speed sensor signal) has been detected.
If you want to check your fluid level, Mercedes-Benz sells a dipstick. The dipstick is part number 001-989-21-03-10 and costs less than $20 at the dealer parts counter.