Drilling Rear Axle for Venting

[CC33]

Has anyone drilled the rear axle to install a vent after installing the torque tube adapter? Is it necessary?

[TomT/Williamsburg]

Yes - did it on the passenger top-side about 10 inches from center of the pumpkin. Tapped and placed a fitting in there for a 1/4" brake line - put a twirl in the line to keep the water/debris out ....

[alanwoodieman]

I have seen some where a drilled stud was used to replace a bolt on the banjo then a hose was run from there. Drilled carb studs were used for vacuum so you may be able to find one.

[Bassman/NZ]

Originally Posted by CC33

Has anyone drilled the rear axle to install a vent after installing the torque tube adapter? Is it necessary?

I've just changed to an open drive banjo with car bells. I too would like to know if this is necessary?

[uncle max]

Drilled mine at about 10 o'clock on the driver's side, to keep it away from the churning ring and pinion.

[Tony, NY]

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I drilled and tapped the axle housing for this vent
http://www.jegs.com/i/Currie/272/95065/10002/-1

[Karl Wolf]

I found that without a vent, there was a pressure buildup from the heat, pull the fill plug after running sometime... This made me think about my rear brakes.

I drilled the torque tube... and added a hose connection.

After trying different positions around the banjo, ALL of them produced oil on ground.

As a refinement, I put an inline fuel filter on the breather, to filter the air...

Karl

[hope]

BUT as CC33 said "is it necessary"?

[JSeery]

If you don't vent a modified rear axle it will build up pressure and can shove axle fluid out the bearings and seals. Everything I have seen tried on the center section has had problems because of the ring gear throwing so much oil around. I drilled my axle housing about a 1/3 of the distance from the backing plate. In a totally stock Ford banjo rear end this shouldn't be a problem because the axle, torque tube and transmission are all vented together. Modification can mess up this system and require an axle vent. I am running a open QC rear axle and it has to have a vent.

[Talkwrench]

Thinking about it where does the standard setup vent from?

[CC33]

Originally Posted by Talkwrench

Thinking about it where does the standard setup vent from?

Ditto. Why isn't the original setup vented?

So I should drill it on the drivers side about 10" from the center of the banjo? Also, say around the 1-2 o'clock position?

[JSeery]

I'm not an expert on original stuff, but it has something to do with the transmission. As long as it is in the system it works. I would guess ether there is venting built into the transmission or it acts as a buffer for the system. I have read all of this in the past just don't remember all the details. It doesn't matter that much to me, if it's stock, it works. If it's modified it needs fixed. Seems simple to me. If people are really that interested in how the stock system works I'm sure I can find the information fairly easily.

[JSeery]

Originally Posted by CC33

Ditto. Why isn't the original setup vented?

So I should drill it on the drivers side about 10" from the center of the banjo? Also, say around the 1-2 o'clock position?

That's one persons option (not saying it wrong, just saying it's an option). It's not how I would do it, but I'm sure it would work. The issue is staying away from the ring gear, not an exact location. A lot of it depends on your setup and the looks, etc. Mine is on the passenger side out nearer the center of the housing on the backing plate side. There are lots of axles with vents on them if you are looking for some ideas.

[Lawrie]

My 33 is stock, and on opening the drain plug I got showered in oil,it was pressurised in there,
How would the pressure get past the oil seal on the driveshaft roller,I know that this seal was to keep the gearbox and U/J oil from getting into the rear end but it would take a few PSI to overcome it from the rear side ,
still I never had any oil in the brakes or loss of oil from the rear,and this was the first time I had drained the rear end oil when it waS hot.
But I agree standard it works,I found this out the hard way this last month or so,engine wise and gearbox wise.
Lawrie

[oldford2]

When I installed the Mitchell in our 46 the Mitchell had a vent in it. Then I started getting leakage around the banjo from the pressure build up in the differential. Apparently in a stock setup the torque tube and transmission buffer the pressure buildup. So here is how I vented the rearend and no more leakage.

John

[FlatheadTed]

The stock set up should not need venting ,on a modified unit a shower restrictor valve from the plumber will do it .Ted

[Krylon32]

On my roadster with QC and steel bells I first put a vent in the left bell about 1.5 inch's out from the edge of the center section and had lots of blow by out the vent. Moved the vent about 1/2 way out on the tube toward the axle end and things stayed clean.

[36tudordeluxe]

The 8" in my '36 came with a vent tube but without the hose attached, where should the hose vent to and should it have a breather on the end of it?

[JSeery]

Only if you don't want water/dust in the axle.

Edit: Well, that was a rather poor answer! First off, I miss-read it, thought you said "do I need a vent hose and filter". Sometimes I wonder about my reading skills. I am doing to have to stop attempting to do several things at once, that's for sure.

Where the vent hose goes is not important, it is normally routed up near the top of the frame and flooring and looped back down a little. The idea is to limit water getting into the axle. It needs to have enough slack in it so it can move with the axle. Filters are not necessary as there is not that much actual movement of air through the vent hose, mostly a pressure relief. However, some people like the extra margin of security a small filter provides.

[36coupe]

On my 38 I found a rubber plug in the torque tube about 8" from the banjo @ 2 oclock and a metal band that can slide over the hole. I thought this was the vent.