Newbie - diff and breather Q's

[macca11]

Evening all,

Got a few questions I hope I will be able to pick everyones brain about. I recently got my 89 gq ute reg'd and on the road, drives well although I may need a kidney belt in the rough stuff ha ha.

When I picked it up it hadn't been driven for some months and there was no evidence of any leak at all from the rear diff. Have done about 100kms in it and now I notice oil coming from the filler plug (no leak from the drain plug), not a heap just wet and an oil mark on it going to the bottom of the diff, not leaving any drops on the driveway tho. Mechanic went over it for roady and fluids are fine, plug feels tight but haven't got a proper tool to be postive.

Is there a seal on the diff filler plug or is it just the thread from the plug? I took the original breather hose off the diff and can blow through it so the hose isn't blocked (blew in from the diff end) - haven't taken the bit out of the diff housing that the hose connects to yet (to dark and will save for weekend) - could this be blocked and forcing it out or would it come out of the axle seals first? Or am I just being extra cautious as this is my first 4x4?

Part 2 of the question is I want to redo the breathers on the diffs eventually and am looking to use fuel line hose and also the fuel filters. I have read a lot of positives on it but also a couple of negatives. The patrol is just a run around on weekends and a camping pig so it doesn't have to be beautiful just practical and reliable - any input/advise/opinions much appreciated!

If I do go down the path of the fuel line etc as above should I install the larger diameter brass fitting to the diff to aid in air flow due to the extra length hose I would be running?

Thanks in advance!!!

Macca!

[growler2058]

I use an electric rattle gun to undo those fillers and drain plugs and my breaker bar without any socket 1/2" drive or is it 3/4" drive to do up. Extending the breathers is a good idea if youre gunna be getting into creek/river crossings

[taslucas]

Hey mate,
My diffs have the same oil seep (front and back). Nothing to worry about if the breather is unblocked and the fluids are correct. Just something that happens i think.
The front diff breather joins the transmission and gearbox breather just in side the passenger side wheel arch. They should join into one line. I just extended that line with a piece of old fuel line and put a cheap ($2.50) fuel filter on the end and attached to the fire wall as high as i could (just under the bonnet)

Below is a pic of the front diff, transfer case and gearbox breathers joining before i extended them. The one on the left is from the front diff, the one on the right is from the transfer case and gearbox. The cutoff rubber hose is where i connected the fuel line and fuel filter

[nissannewby]

Pull the plug and whack some thread tape on her they are just tapered plugs and the thread tape will help it seal. It could also just be residue from when the oil was checked and as its thick oil in the rear will tend to hang around until given a good wash.

[macca11]

Thanks for your replies. Turns out there is no blockage in the rear breather hose which is good and will redo them both on the weekend. Taslucas thanks for the pic, very handy!! Will tape the thread also.

Cheers
Macca

[Silver]

based on my experience with MQ and GQ, don't be tempted to do them up super tight, to prevent future leaks.

Thread tape sounds like a good idea to help the seal and make them easier to undo.

[Lieney]

An alternative to thread tape is loctite 567. Its a liquid thread tape and is brilliant for things like that. I've used that over the past 16 years for threads and never had an issue, warranty job etc and will only use thread tape for plumbing at home, when 567 isn't satisfactory.
When I extended my breathers, I used plastic air pressure line used in trucks (5-6mm OD approx). Its real cheap and easy to route & zip-tie to chassis etc and takes up less room than running fuel hose.
I cut the existing breather line and jammed the plastic line, gluing with a suitable adhesive, into it the diff end and then routed the line up into the engine bay. I used fuel hose to connect a filter (was the existing valve).I didnt connect them, I kept them seperate.