Breather valve for rear differential
 

Where exactly is this breather valve located and what it looks like ?
I have read and seen the procedure on this but can not locate it now. It was well written and had a picture of the breather valve.
I am about to replace the differential oil and would like to clean this valve. Is this something that should be done or not critical?

Thanks

Looking from the rear the breather is on the rear passenger side of the differential. Its about 1.5 inches and looks like a mushroom----you will see an opening in the frame to access and remove----just make sure the area is clean before removal as you do not want all that crap falling in the differential.

Thanks for the info.
 

My guess is not too many people or shops actually clean this valve when servicing the differential.

On the W210's it's a fifteen dollar part that takes about .5 hr to replace/clean properly---it's not a scheduled item therefore most folks will provide all sorts of excuses not to change---Oh well

Clean or replace the valve?
 

Is it better to just clean it or replace with new breather valve?
Easy access and any special tool to remove?

Easy access and any special tool to remove?<!-- google_ad_section_end --> ------yes amd nope!

Is it better to just clean it or replace with new breather valve?-------That's a personal choice, I am in the business of replacing things not cleaning things!!

Mobil1 synthetic 75w-90 or Castrol 80w-90
 

Which is the better choice to use? Dealer does not have the 85w-90.
Also the breather valve is special order item at around $42 ...so maybe cleaning it and reusing it would be ok this time.

80W90, but have you checked a truck repair center!!

Autozone has both of these oils.
 

The local MB dealer is sell the Castrol 80w-90 but a few bucks more than Autozone of course.
I guess the other real question is to go synthetic with Mobil1 or regular oil with Castrol.
Is the original hypoid oil synthetic or regular ?

If you are going to p and moan over a couple of bucks and then use incorrect fluids you will be back whining about your car----do yourself a favor sell the car!!