Hi again folks. We decided to change the oil in the 1996 XJ6, and ran into a block. We found the lower drain plug just fine and saving that till later went looking for the fill plug, Only to find there wasn't a metal plug like the drain plug, but what appears to be a plastic breather cap instead. After much study we got the outside of the cap off (pictured). We pushed some oil into it and it seemed to take it just fine, but we didn't want to drain any till we were sure. Most descriptions for the fill plug I've seen online say it's a metal plug. This derailed me for a bit as I hadn't seen any descriptions of a plastic plug. I wanted to stop by the forum here and verify that besides being a breather cap that this is where we should be filling the oil? .









Any comments, suggestions appreciated.

Thanks,

Bobby

 

G'day Bobby,

The plug in the alloy rear diff cover is the "fill" plug, the "drain plug" is on the bottom surface of the steel part of the diff which can be accessed through a hole in the the large tie plate which covers the bottom of the whole suspension unit. Have a look at this pic.



Drain all the oil through the drain plug and fill through the fill hole until the new oil just starts to overflow and then replace the fill plug.

From memory I used a short socket extension male end to undo the fill plug and the female end to undo the drain plug.

Cheers,
Jeff.

 

Thanks Jeff, so the steel plug with the square hole (in my top picture) is actually the fill plug? Admittedly I did not look around the bottom surface of the diff. I'll check that out ASAP.

Thanks!!

Bobby

 

Hi Bobby,

While you have the cap off the breather, clean it with brake cleaner spray, a pipe cleaner and compressed air if you can get a blow tip up there. A clogged breather can cause pressure to build with temperature inside the diff and promote oil leaks from the seals.

Cheers,

Don

 

So you broke the breather to try to get oil in the diff??

bob

 

No. Not broken. It came apart and went back together again just fine. It looks again like it did in the first picture.

Don, when it was apart we did push some oil into it without issue (a few ounces). So I guess if it was plugged, then it's clear now!

Bobby

 

In your first photo the metal plug with the square recess is the filler plug, above that is the breather. Given age, heat and being plastic I'd be very surprised if the breather wasn't broken now, as they are not designed to come apart.

 

The breather cap just snaps on to the breather tube. If you're careful, you can usually pry/prise it off without breaking the breather tube. This is how I clean the breathers. But you're right, you have to be careful with old brittle plastic parts.

Cheers,

Don

 

Thanks Gents, we got lucky then. The cap(s) popped off with a gentle bit of force and went back on with a click. Still has a nice little spring action when I press down on it. All is well.

Bobby