FJ60 Rear Diff Breather Question (1 Viewer)

[chbrow10]

Hello,

1987 FJ60 stock rear axle. Diff breather is in stock location and has evidence of leaking oil. Here is the timetable:

1. About 2 months ago I opened the rear diff fill plug to check the fluid level. Fluid was at the fill hole and clear amber in color.
2. About 2 weeks ago I went wheeling and did a fair amount of driving through the water. Nothing crazy, no water inside the truck or anything. Deep enough to get water in my distributor and make it unhappy.
3. Today, for unrelated reasons, I changed the rear diff oil. Prior to doing this change, the truck had been driven for a few miles. When the fill plug was removed (drain plug not removed yet), oil immediately came out the fill hole, meaning the liquid was above the fill hole.. When it came out, the oil was forest green, not milky white green. Drain plug is boogered, so I used a pump to remove the old oil through the fill hole.
4. While I was under the truck, I noticed that the diff breather was moist from the top (at the breather) all the way back down to the axle. The breather itself was black and crusty.
5. No oil is leaking at either rear hub at this time.

I believe water got into the diff as the oil had changed color and there was more liquid in the diff than there was a few months ago. I don't see how water got above the diff breather in the stock location, as that would have meant I was in water over the door sills, and I don't think that happened, but it could have.

I have the following questions:

1. Do I need to do anything to my breather, like replace it?
2. Could this just have been water ingress from the breather?
3. If the hub seals are going and they are the source of the water, wouldn't there be diff oil leaking out at the hubs?

Thanks for your help.

 

[kirvesmies]

1)if the top of it moves, twists, you don't need to change. just a quick blast of wd-40 to clean out the inside
2)yes, quite likely. extend the outlet. 1/4 or 5/16 dia flexi line with cheap plastic fuel filter at the top. i usually run mine to the top of tail light area. front axle up to just under hood center of fire wall
3)most likely. also if the top of the vent is stuck, that means it's not venting and the air pressure in the axle housing will push gear oil out the seals. can be pinion or axle seals
there's various write ups to be found in the interwebs
or stay out of water deeper than the lowest part of your wheels

 

[chbrow10]

The top of the breather moves. The hose looks original and is very stiff. I will put its replacement and relocation on the list.

 

[SteveH]

The top of the breather typically moves, which indicates little, but sometimes the rubber disk underneath the cap is stuck to the top of the axle fitting. So, pry off the wobbly cap, remove the disk and spring, slide on some 3/8" fuel line, install a hose clamp on the axle fitting to fix the hose, and then run the hose as high as you like.

You can install a fuel filter on the end of the line if you're worried about dirt. The nice part about doing this is that it ensures that your axle is never under a pressure or vacuum, which keeps the oil inside and the water out.

Do this on your front axle and transfer case, as well.

 

[bentonrover]

I literally just ordered these. Use some spray silicone when putting them into the hose. Also a good time to extend them with longer hoses.

 

[bwesty]

1/4 fuel hose from the axles and tcase into the engine bay with cheap VW style plastic filters plus hose clamps and zip ties. I like routing into engine bay to be able to get them up high and easy to check once in awhile. Be sure the breather fitting on axle is clear of any gunk, etc.

PRO 1 Fuel Line Hose 1/4 Inch Inside Diameter X 25 Feet Length NRB/PVCC SAE30R6
Amazon product ASIN B00UVNYUUC
Universal Fuel Filters (Clear for 1/4" 5/16 Fuel Line) Kohler, Honda and Others
Amazon product ASIN B00XQ0HTBO

 

[Godwin]

1/4 fuel hose from the axles and tcase into the engine bay with cheap VW style plastic filters plus hose clamps and zip ties. I like routing into engine bay to be able to get them up high and easy to check once in awhile. Be sure the breather fitting on axle is clear of any gunk, etc.

PRO 1 Fuel Line Hose 1/4 Inch Inside Diameter X 25 Feet Length NRB/PVCC SAE30R6
Amazon product ASIN B00UVNYUUC
Universal Fuel Filters (Clear for 1/4" 5/16 Fuel Line) Kohler, Honda and Others
Amazon product ASIN B00XQ0HTBO

This is the way to go. I have used this method on the axle breathers and also with the clean air intake on the distributor cap (2F, 3FE).

 

[Tennessee80]

This is the way to go. I have used this method on the axle breathers and also with the clean air intake on the distributor cap (2F, 3FE).

If any mod calls for zip ties I’m in!

 

[JamesR]

I removed the front and rear diff breathers, used fuel line, and ran the line to under the hood.