Good Afternoon,




I purchased this vehicle not too long ago and have been learning quite a bit about the Mercedes 722.6 transmission. While trying to replace the leaking pilot busing, the 7mm nut broke and now I have to remove the pan and replace the conductor plate.


I can't seem to find a consistent recommendation on the proper way to check the level once it's all back together and I'm ready to fill it back up. For example, Mercedes Medic says add 4 quarts, drive 15 minutes, and then check. The ATSC manual says check with the transmission warm, and others suggest measuring the actual transmission temperature.


Do I just drive the car for a specified time, assume it's warmed up, and then fill to a certain point on the measuring tool? Or should I read the actual temperature and if so what is the preferred way? Thanks for any suggestions. I have serviced transmissions in the past, but not yet one of these.


Thank you,




Rob

 

https://www.harborfreight.com/infrar...ter-93984.html

 

Thanks for the link.


Also, does anyone know if it's possible to tap out the broken pilot bushing bolt? Or just too small and difficult to access to bother with?

 

My understanding is that when you ping the tranny pan with infrared (which I do) is to add 10 deg F. Also, make sure to use a proper dipstick with "ears" that cause the dipstick to hit the stop before the dipstick bottoms out on the pan. (regardless of what some "factory" info may state). Reference Avos in years past.

 

Thank you Dr. D. I got the conductor plate, pilot busing, new filter, and pan back in place. I added 4 quarts of oil and the car would hardly move. I then added a 5th quart and it drove great. After driving the car for 15 minutes I checked the level (with the actual Mercedes Benz measuring tool with the ears) and nothing would register. I then added another 1/2 quart and nothing registers.


The measuring tool goes in 19" before it hits a stop and I can't get it any further. Does this sound about right? So far I've added 5 1/2 quarts with nothing registering on the tool with the tranny warm. I'm afraid I'm not getting the tool all the way in and don't want to risk overfilling the transmission.


If you can shed any light on whether or not I'm doing things correctly, I would appreciate it.


Thank you,


Rob

 

If I recall correctly, You lost close to 7 qt. when you removed the pan and replaced the filter. The four qt. is a simple drain and fill.

The procedure I followed said to check fluid at 80 deg C, which is close to operating temp.

 

Rob:
Mine measures~23"top of tube to the ears. I did have a few kinks along the way. It is possible for the ears to wear and the stick bottom on the pan. According to Avos, that would be ~3/4" deeper. I do not think I hit the bottom of the pan, but it would be wise to get another measurement or two from other owners. I do checkout the stop situation each time I drop the pan, but I really should have had this reference dimension for in between times.
Congrats on successful conductor plate replacement.

 

Thank you for the reply. So sounds like I need a bit more fluid. I'll add a bit at a time at operating temperature and go from there.




Regarding the conductor plate, I have never been that "deep" into a transmission before but it was actually very easy. Messy for sure though.




Rob

 

Rob:
I finally dropped the pan today and got an accurate measure. Mine did indeed measure 23" from filler opening to the stop. I have recorded that measurement for future reference. I understand other's results may vary.

 

Ok so just to clarify, your measuring too goes in 23" before hitting the stop?


Mine goes in 19" and still does not show any fluid even after adding 7.5 - 8 quarts which makes me think the measuring tool may be hanging up.






Rob

 

Correct, I marked the dipstick even with the top of the filler tube, then measured from that mark to the "ears" (23"). There could be an obstruction or the tip of the dipstick is too wide. (My tip is 0.250" wide and my "ears" are 0.357" wide.)

 

Ok good point I will measure those. Man, is it too much to as for just a standard dipstick?

 

You got that right. My 2003 Dodge Ram Manual Page 21-543 for the 545RFE 5sp Tranny Fig. 66 shows the dipstick fluid level (mm) vs Temp (F) chart (which I use) in the same fashion as the 722.6 Merc chart except my truck (just like all the others) indeed has the factory installed traditional stick.