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Gear Oil Jug Spout: I should have done this years ago


NAXJA Member
I don't know what everyone else does to get gear oil into a diff/T-case/tranny, but I have generally found it to be a PITA. In warm weather I found the pumps to be the least annoying method, but now that I live where it gets cold the pumps are more of a workout than I care to endure anymore. Cold gear oil just doesn't want to move. So I tried going back to a short piece of hose on the nipple that is on the bottle. Problem is, the nipple on the bottle is tapered such that the hose always wants to come off. Add a bit of lubricant, like gear oil, between the two and the hose spends more time off than on. And gear oil has such a wonderful scent to get in your hair.

I finally got fed up, temporarily put the refilling of the differential on hold, and went scrounging through the shop to come up with a better solution. And I found one. There are probably others, but this is what I came up with using parts on hand:


The first part needed is a decent hose fitting that won't let the hose come flying off when you squeeze the bottle. I found a 3/8" hose barb with a 1/4" MPT end.

Next I needed a nut. Pipe threads don't lend themselves to nuts on account of their being tapered. Fine. I cut a coupling in half. That got me a "nut" with the right taper.

Next issue is that the "nut" doesn't thread down all the way to tighten the fitting to the bottle cap. So I needed a couple of washers.

For the outside washer I think I used a nominal 1/2" washer. The ID wasn't quite large enough however, so I drilled it out with a 17/32" drill bit. That worked for the first one I made, but when I picked up some parts to make a few more of these (because Varmints) the next batch of hose barbs required me to step up to a 9/16" drill bit, hence the two bits in the picture.

For the inside washer it was slightly more challenging. The inside washer needs a properly sized ID and OD. The same 17/32" or 9/16" will work for the ID, but the OD must also be sized such that it will fit through the opening in the bottle. Otherwise the cap will not thread all the way down and seal properly. I wound up turning these washers on the lathe to get them down to the size I needed. I think I started with nominally 7/16" washers. Had I thought about the OD I probably would have started with something even smaller. Of course the smaller they are the harder they are to hold while trying to drill them out.

With those parts in hand it is then just a matter of cutting the nipple off a cap, drilling out the hole a bit further to fit the pipe fitting and assembling with the washers and the "nut".

For the hose I found some pieces of clear tubing. Might be some kind of vinyl. I have seen it in home centers/hardware stores. Usually with warnings against using it for ice makers. I think what I used is nominally 5/16" ID (measured with the smooth end of a drill bit). It was stiff going onto a 3/8" barb, but a little help from a heat gun got it where I wanted it. And then I added the Corbin clamp just for insurance (really trying to avoid wearing any more gear oil). I did a lousy job with the pic. The Napa P/N for the Corbin clamps is 705-1300.

The 5/16" clear tubing seems to be the perfect size for my application. Any larger and it would not fit in the fill hole in my OX diff cover. Others may find that 3/8" is fine.

At any rate, this makes the job far easier. I could punch an air hole in the bottom of the jug and walk away while it drains:


And I won't have to spend nearly so much time fighting this situation:


I should have done this years ago.
You know ,you could just bring the oil jug into the house and set it in a bucket of hot water ,for awhile:D

I like your solution to the problem.Tha hose just slips off that tapered spout no matter how tight the clamp....
You should see the looks I get from The Bride when car parts come into the house. She particularly loves it when I use the oven to warm up timing gears.

I try to reserve my points for buying yet another Jeep.
Seems like a transfer pump of sorts might be easier?

With Ford 9-in front and rear pumping is about the only option I have; filling and draining. I use the hand pump that screws on to the top of the gallon jug. Thought about a drill powered one... But the thought only lasts as long as while I'm swapping fluids. Brain can't seem to remember to buy one for a drill otherwise.:doh: