isellbenz

I have searched high and low and have come up with nothing. I need help. I have had the output seals and diff cover seal replaced and I am still getting a little drip. Upon inspection myself I have found that the fluid is leaking from breather on cool down. We have checked fluid levels and found that all is well. I have been presented with 2 options; change fluid or replace breather vent.

Currently the car has 80/90 in it and I have been considering 75/140. I am leaning towards fluid being the culprit due to some of the reading I have been doing about LSD's and their different requirements. My car IS in fact fitted with an LSD and I am running the 80/90 which Benz has suggested works fine.

Currently after long trips on the highways as I exit and slow, the car groans in the rear when shifting into 1st. A sign of overheating, maybe??

Any tips, suggestions etc... would be greatly appreciated. I am at my wits end with this.

isellbenz

???

Yuille36

The only thing that I can think of at the moment, was the diff housing matting surface throughly cleaned? Was there a possibility that too much diff fluid was put in, thereby causing too much pressure to build up inside that caused the fluid to be force out?
Granted, I'm only a shade tree mechanic myself, but I do have skills.

TTMotorsports

Change the fluid. I have seen this on CLK63 BS at the track. You are overheating the fluid which also aerates it to cause the overflow condition.

If some fluid leaked out and the fluid level is still good then it was overfilled and that might also be the culprit.

What fluid brand are you running and what LSD are you using?

isellbenz

Right now I have 80/90 Mobil1 in there. Car has the P030 pack LSD. MB Said the 80w90 is what it called for!! I was thinking Royal purple for the lowered op temps, however I am getting nervous about using something other than Mobil. I was thinking I would use 75w140 RP and see what happens.. Ive been stewing over this for a LONG time. Been driving my S4 and I really want to get the 55 out now that the weather has cooled off and give her a romp. Any thoughts TTM?? You'd be my hero.

pearlpower

I would stay clear of running that thick, and instead would opt for a nice cooler available from many sources.

isellbenz

Any particular reason the 75w140 wouldnt work? Are there foreseen problems using this type gear oil? Man I am so frustrated with this. I don't even drive the car hard. Just seems if i get it out on the highway for 20 min or a fair amount of around town driving and this thing blows off.

TTMotorsports

Motul Gear 300 75w/90 is what we currently use and you will not aerate/foam the Motul. You could also use Motul Gear FF Competition 75w/140 which we also use. Either one and you are good to go! Problem fixed.

I would only consider using Motul. Why not use the best?

isellbenz

TTM!! YOU'RE AWESOME! Thanks to everyone who chimed in!! Will definitely remember all the help!!

isellbenz

@#$%ing thing is doing it again! I had over a week and a half of driving.. even was a little rougher on the old girl and stayed BONE DRY! Now its leaking again! WTF?! Nobody experiences this??? I'm going to try to get pictures up tomorrow.. Anyone know how these breather vents look or operate?

isellbenz

Anyone know how to... or ever replaced the diff. vent? I think I just have too much pressure building up do to a clogged vent. Instead of blowing out the seals, its finally popping off and spoooging all over the garage floor.. Hoping there is a way to get this thing with out tearing it down completely.

jcjmw

If I remember right, I had a similiar problem within a few months when I initially got my 55 Wagon (back in 05). The dealer told me it was the vent itself. I am not sure if that makes any sense, as I have never looked at the Diff/vent areas, but after the dealer replaced the vent or did what they did no problems since and it has been years.

isellbenz

It's definitely the vent, as I have already had everything else replaced. I'm pretty much settled on replacing the vent, however I do NOT want to drop the rear end. Has anyone tackled this? The vent is only $30 or so, but is it press in? Is it possible to work on with out dropping the rear down? CAN it be cleaned? Can't believe I could have the only E55 with this problem... I've read a bit about the CLK63 BS blowing off through the vent, but nothing on ours.

jcjmw

Sorry, I don't remember exactly how the dealer did it. It was so long ago. However, you could sign up at

http://www.alldatadiy.com

its a website that provides DIY information for various cars. Its really good. I am sure that site will tell you how to replace that vent with tools and parts needed. Good luck.

isellbenz

I've got alldata pro. Just doesn't get into any info on the vent.. BUMMER!

isellbenz

Since the fluid change, it was dry for a week or so.. Now I have a MASSIVE leak issue. It's soaked and I have a hard time believing it only the vent at this point. Should've left the damn thing alone..

jcjmw

For the 2nd time in 6 years, my rear end was leaking. Appearantly, the vent in my differential needs to be replaced, again. Its covered under warranty...but I have to wait unti tomorrow for the car to be ready b/c the part is coming from Ca....urgh

For informational purposes, the attached pics are from another site but they provide a general guide as to what I am talking about. Also, I am told that the rear axle on the differential side of the vent has to be out in order to replace this stupid thing.

jcjmw

Here are the attachments.

isellbenz

wow.. mine looks NOTHING like that. I'll have to get pics. The car has been parked now since Oct 1 so I haven't messed with it.

Sal1984

The opening of C clips that holds the side bearings MUST be pointing upwards. There are two holes (one of each side) that would be blocked by the C clips if not placed correctly. I suffered the same after installing an LSD, and now its Fixed after I reopened and repositioned the clips. Hope this helps!