Rear Diff Breather

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Mar 13, 2003
North Front Range, CO
I went to check to see if the rear breather was plugged. I took the line off the diff and went to blow in it. Some sand like stuff fell ion my face :'( The breahter wasn't plugged. I cleaned the line with carb cleaner. Checked the vent hole on the diff it was plugged. I poked the hole clean. I should of drained and filled the diff but I will be rebuilding it soon so I didn't.
What would the stuff be that was in the line and plugging the vent port on the diff? I didn't see what the stuff look liked.

What I have found in the past is generally rust looking stuff. I think it is from condensation in the axle housing. That reminds me, we should all check the breather nipples regularly for just the stuff Kurt has found. It is not a rare thing at all and you don't have to take the cruiser for a swim to have it happen.

Another tangent: We got a bit of rare rain 2 days ago and it turned the dust in my rockers into mud AGAIN and plugged the drains. I turned down Frank Sinatra and heard the tell-tale sloshy sloshy on the way to work this morning. Don't forget to check those too.........
Student raises hand in class and makes funny noises :-\

How do I clean the diff breather hose?

Pull of the hose from the diff housing and blow?

If it's plugged back at the diff fitting then it sounds like a drag to have to poke junk back into the diff. :banana:

Is this basically it?


I prefer to use a pipe cleaner. And yes, you may push some of it back in. I doubt that the little bit of goo that would be pushed back in would really hurt anything. If the thought bothers you, I would suggest cleaning the tube when the axle is hot and then going for a bit of a drive (say 10 miles or so) and then drain an refill the diff. Perhaps that could be incorporated in your routine for doing an axle lube service. In fact, I think that I like what I just came up with accidentaly. I'll do that next time.
Or you could take the fill plug off, put your lips on the hole and blow as you unplug the port :D
Most of the time its the breather thats pluged as on most vehicles it is on the diff an not on a hose like ours. Had I not removed the hose and blew through it and got crap in my mouth, I would of not known that the port on the diff was pluged.
This explains whay I had gear oil in my rear wheel bearings. THe axle seals were acting as breathers and the oil was being pushed out too.

I wounder if I should repack the bearings again. Now that the breather is not pluged I wont be getting fresh oil in the wheel bearings but what ever amount that got in there is mixing with the grease ???

It certainly wouldn't hurt to look. I think all you would need to do to check would be to pull the axle shaft and look at the nut and outer bearing area. If there is no gear oil there I wouldn't bother going any deeper. This also got me thinking, as that little seal is what fails and allows gear oil into the bearings and it's a snap to pull the shaft, maybe it would be a good idea to go in there about every 15 k or so and replace that seal. They are cheap and the whole job(both sides) could be done in under an hour. :)

If you can do that in 60 minutes, you should join the Penske pit crew. Don't forget you've got to remove and replace the calipers, readjust the rear parking drum brake, repack and retension the rear wheel bearings, drain and refill the diff, etc. Heck, I don't think I'd have it fully apart in 60 minutes. If you have air tools then I have to consider that cheating...


He's dreaming. It would take him 4 or 5 hours; 4 with 4 pints of Boddingtons, 5 with 8 pints.


Yeah, I'm with you. Particularly the Boddingtons comment - I had a buddy in Texas rave about it so much that one day I simply said "there's nothing new in the beer world that can be that different or tasty - you're full of it" A week later a couple cans arrived in the mail. Not only is that stuff incredible, but each can has a high tech gizmo that required destruction of sheet metal and some blood to get to - all high on MY project list. As a double bonus, said carbon dioxide gizmos are now full time cat toys. Sorry to hijack the thread briefly, but these are little plastic spheres of CO2 that have a blow off valve. Said blow off valve won't release due to high pressure inside the pressurized beer can. Pop the top, and pressure drops to ambient levels and the little sphere opens up and turns that beer into the smoothest thing this side of a teenaged girl's chest. (no offense to those who have teenaged daughters - mine's 5 and I don't have to worry about that stuff yet). If you haven't tried it, you should. The beer that is, ya knuckleheads :D

Guys, guys.............

I'm refering to the little seal that is in the end of the axle housing. You know, the one that would leak gear oil into the wheel bearings? ::) .Geezzzee.

6 nuts, 6 cone washers, slide shaft out, pop seal, set new seal, slide shaft back in, 6 cone washers, 6 nuts, beers....... ;)

Oh , BTW,
The WIDGETS are NOT to be removed from the cans. ::) Didn't you read the label? How else could you possibly know that they are a whitish plastic that looks just like a small fishing bobber............... ;)
:) :) Heh - I got curious after about the third one and pulled out the trusty keychain pocket knife. My bad on the rear axle seal as you note - w/o the birfield, this seal's a piece of cake to access. My rear bearings were awash in Mobil 1 gear oil when I got in there last year - not a trace of grease. Now that you point it out, this might be a biannual seal swap, though it will undoubtedly take me a half day....


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