hello folks,

I was doing a rear differential drain/refill a few months ago and I noticed quite a bit of dried up sludge and gunk around the plastic breather. I made a mental note to order one and replace it next time it was due for an oil change (which is coming up sometime next week hence my inquiry below)

The dealer does not seem to list a part # for the x300 breather and I am not having any luck finding it online either.

Is there a proper part # for this piece? More importantly, how do you remove it?

Based on my limited observation last time it was on the lift, I am pretty sure it doesn't come out using any type of a socket because of the close proximity of breather cap and the cooling fins on the differential casing. Any socket I tried would hit the differential cooling fins. I assume it's held in place by a circlip of some sort? To complicate matters, the XJR has a rear swaybar, and it makes accessing the fill plug a challenge already, much less trying to maneuver pliers to remove some obscure circlip even further up.

What's the best way to tackle this? clean the existing one or replace it?

If a replacement is not listed/available, how do you properly clean it if it's buried in gunk and dried up sludge? There's a spring of some sort under the cap and for it to function properly, it needs to be cleaned internally. I am not sure how it would even be possible to clean it properly unless it's removed first.

Would love to know your thoughts on this.

Thanks in advance.

 

Here ya go.

Breather assembly JLM631.
Breather o/ring JLM620

Now these are ALL on the parts catalogue under "un-illustrated" parts, so I have NO idea how it comes out.

In that same section is an external circlip, JLM1710, but again I have NO idea if its related to the breather or just another un-illustrated part????.

I would get a thin screwdriver and carefully pry that gunk off, taking your time. Then get a p/pack degreaser, and soak it real good, and a toothbrush, and clean it as best you can. OK, I know that is only the outside, but anything cleaned MUST be better than doing nothing.

The old style had a plastic cap on top that did rotate if you were careful.

 

would anyone have any schematics of this breather to show what's under the cap?

how would you remove the circlip considering there's no room there?

thanks

 

I know this is an old thread, but thought in this case it made sense to revive the thread instead of posting anew...

My mechanic advised me of a slight differential seal weep a couple months back, and I've read repeatedly that one of the top causes of differential leaks is not worn seals but breather blockages. Once cleared/cleaned, the breather lets the pressure escape once the diff is up to temp versus pushing gear oil past the seals.

So that being said, I've read a number of threads for the X300 and X308 differentials related to breather cleaning, and unfortunately I didn't find one that clearly illustrates how to clean the X300 differential without pulling the diff cover. Even those "cover off" examples didn't seem clear on their method or success, unless I missed the best thread on the subject

So, does anyone now have any tips/guidance on cleaning the breather successfully from the outside?

.

 

When I re-did my rear suspension bushings, the entire rear end was filthy from an apparent dirty breather. I cleaned it up with degreaser and then I think I sprayed brake or carb cleaner to clean it out. The rear end has stayed nice and clean ever since. I also changed out the fluid as I also installed XJR/X308 mono tube which blocks access to the drain plug for the diff.

 

The monotube blocks access to the drain plug? Or do you mean the fill plug?
Honest as I've had my monotube for a few months now but haven't installed it since I haven't ordered my poly bushings for it yet either. should changing out the diff fluid be something done while/before installing the monotube?

 

Fill plug not drain. The monotube eiminated all of my 3-4 shifting slop and really tightened up the car. The issue is that the Powerflex poky bushes are a tad too wide for the upper mounts. Those are a b!tch to get aligned.

 

I know we're a little off-topic now, so maybe best to answer in your "monotube install" thread, but how did you finally get the poly bushings to align?

I remember your talking about the the challenge, but don't recall if you ever posted what it took to get them finally lined up.

.

 

Hi After reading your problem on the breather tube i inspected one i have from a xj 300. S/C in my garage as a spare. I gently levered the hat of (i dont have part numbers) That hat as i will call it has several small protruding dimples which clip over a slightly larger lip on the tube and inside the hat is a smaller bung that fits inside the tube but has a outer lip as to not go all the way in the tube. Once they were removed you can then see a circlip the type with little holes in so you can expand it with the right type of circlip pliers. I thought i could now pull the tube out' but no in Jaguars wisdom once the circlip is removed it comes out by pushing it in so the cover unfortuantly has to come off. Hope it is explained well enough.The other option is to remove the hat and may be blow some air thru it once you have drained the oil. Hope this helps
Cheers Ray.

 

Indeed, thanks.

So, in your opinion the "hat" is meant to be removed and reinstalled by pushing it back on until it clips back on again? Were you able to confirm that the "hat" and insert would reinstall properly by reversing the procedure?

Also, I wonder if once the hat and insert/valve are removed, perhaps one could just run a pipe cleaner into the pipe to clean it out.

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Yes i tried it several times levering off with screw driver and pushing it back on no problem. Just be carefull not to lose the insert as it may drop out when the outer hat flicks off. Pipe cleaner should be fine to use mind you the tube is made of a hard plastic
Cheers Ray.

 

I've read elsewhere that differential breather unscrews. Breather tube seems to vary by application, but it is located near top of diff. and unscrews.

 

The diff fill plug comes out easy as pie with a 1/2" wobble extension when you have the mono strut.

Like this:

3-piece-1-2-half-inch-drive-impact-wobble-socket-extension

 

A long while back I thought the breather cap was the diff fill cap! I pried it off somehow. Thought it looked odd as a fill port, and it fit loosely. I actually added diff oil through the tube! The cap snapped back on. At some point later, I discovered the fill plug and went back and drained some excess fluid. No harm done.

I concur that the cap is a snap on, as "On edge" shared above. Blowing air into the fill hole and letting it escape the breather hole sounds like a sound idea. Then a manual cleaning of the cap should settle it.

 

I had mine plug a couple of years ago that resulted in the right hand seal leaking. To make a long story short. I solved the leak problem by rotating the breather cap ever time I have it on a rack. And I mean rotate it a lot of times. That keeps it from plugging up and keeps the seals from leaking. Problem solved.

 

sorry if I am bringing the thread up again.
I have the same problem right hand seal leaking. I Cannot locate the breather. There is no picture so that I could find where is it exactly ?

 

Don't know if this is the correct model # and it's orientation

 

That's about it Lady P. Orientation is accurate. Upper cap is breather, lower plug is fill plug with 1/2" square fitting. Very dirty, wonder if this diff was over-full. Of course the view of this is not so easy on a car! Jack up and remove right rear wheel for better access, or get on a lift.

 

I haven't looked into it yet, but my plan is still to see if the "cap" can be pried off the breather for cleaning, then pressed back on... or worst case ruining the cap and then affixing a hose to the breather tube.

I was told by a mechanic a couple years ago that the seal was weeping (I forget which side) and I've smelled gear oil after a long drive a few times wafting up from the rear. So I'm suspecting the breather is gunked up, which is causing the gear oil to seep.

Lately I've started to hear a bit of whine from the rear, so I think I'm low. So it's time to look into it.

.

 

Interesting options but there are post on the vent's removal and cleaning in posts that I saw . I like the vent tube with your solution but not into the trunk . Bring the hose up high before turning down to your vent point . There was a post on a tube though the trunk for easier servicing though . Mine fortunately does not have the sound of trouble ( yet ) and haven't really looked into it .

First priority is the ensure that it's serviced to the proper level and maybe flush the old oil out as it may be compromised . There are post on the recommended oil to use .