Is There an Axle Vent or?

J

jg61hawk

Senior Member
Is there an actual vent hole in the rear axle or differential or does all pressure get relived through the vent in the shift tower.


I can't find any reference to an axle vent in three books and I can't find a vent. I'm thinking perhaps because of the tubes all pressure goes to the shift tower. Please advise oh great masters of the Model A universe! Thanks. Jim.


If there one PLEASE tell me where to look.
 
I don’t know of any vent. If there is any pressure in there, it should find its way out one of the three seals. Two axle and the driveshaft seal. It would never get up to the tower. Certainly nothing to worry about.
 
My vent was in the right rear axle housing, worn by a broken shackle, it has been repaired .
Yes there isn’t a vent in the rear axle.
 
There is no vent for the rear axle. It is common for the pressure to force the oil out the hub seals. I'm looking at the possible insertion of a pop valve somewhere on the banjo to relieve the pressure.
 
jg61hawk said:
Is there an actual vent hole in the rear axle or differential or does all pressure get relived through the vent in the shift tower.


I can't find any reference to an axle vent in three books and I can't find a vent. I'm thinking perhaps because of the tubes all pressure goes to the shift tower. Please advise oh great masters of the Model A universe! Thanks. Jim.


If there one PLEASE tell me where to look.
Click to expand...
No, not stock there isn't.
However, it is not a big deal to install a vent like a little more modern cars had and it's a good idea ,,,if done properly.
 
Just a FYI, the rear axle cannot vent thru the shift tower or the speedometer drive if the seal is correctly installed. The design of the seal in both axle housings is such that pressure will force the lip to the axle shaft.

The place where the air CAN vent is between the torque tube and the differential (banjo) housing as there is not a gasket there. Because the rear end assembly does not get hot due to friction from gears or bearings, there really is not a need for a vent however if someone feels compelled to add one, then remove one of the axle housing to diff. housing bolts at the top and drill a 1/16th inch hole thru the middle in the center, and re-install the bolt. That would give it a place to vent without a noticible alteration.
 
Not really sure you would need one.

My car hasn't had one in 87 years, so I don't see the need to add one just because new cars have them.

Regards
Bill
 
BRENT in 10-uh-C said:
Just a FYI, the rear axle cannot vent thru the shift tower or the speedometer drive if the seal is correctly installed. The design of the seal in both axle housings is such that pressure will force the lip to the axle shaft.

The place where the air CAN vent is between the torque tube and the differential (banjo) housing as there is not a gasket there. Because the rear end assembly does not get hot due to friction from gears or bearings, there really is not a need for a vent however if someone feels compelled to add one, then remove one of the axle housing to diff. housing bolts at the top and drill a 1/16th inch hole thru the middle in the center, and re-install the bolt. That would give it a place to vent without a noticible alteration.
Click to expand...


this is what i did and then installed a small piece of brake line thru the hole and bent it around so water or other dabree can enter the small tube
figured it can only help the seals

Tinkirk/Terry
 
BillCNC said:
Not really sure you would need one.

My car hasn't had one in 87 years, so I don't see the need to add one just because new cars have them.

Regards
Bill
Click to expand...

Old school is a good thing but, sometimes new school can be a better thing,
one thing to remember Henry kept improving thinks every year in other words he learned new stuff all the time and was not totally stuck in the past!

Tinkirk/Terry
 
I had to add a vent when I installed the Ryan OD. I first did it as Terry suggested but oil also leaked out of there. I then put one in the outer end of the left housing, solved the problem.
 
Pretty sure there IS a gasket between the banjo housing and the torque tube. If not, fluid would leak here since the fluid level is above the bottom of the torque tube hole in the banjo housing.

As for venting the rear diff... One of the guys in a neighboring club did that before heading to the east coast in his Model A. Blew the rear end after it went dry due to losing too much fluid out the vent. When driving, the differential fluid is flung all around the inside of the banjo housing. The goal is to keep it in there. Leave it stock!
 
Jim Brierley said:
I had to add a vent when I installed the Ryan OD. I first did it as Terry suggested but oil also leaked out of there. I then put one in the outer end of the left housing, solved the problem.
Click to expand...



Yup, your cure is similar to the way it was done later on at factory axle housings.
Some are saying to drill into banjo /bolts, etc. That is asking for oil leak.


If a guy ever checked the way the factory built this vent. They put a little 'hat' looking top on the vent and , as you did, added it toward middle/end of TOP of axle housing.


Hm, wondering if I should take the gasket out from between torque tube and banjo now ?
 
Not sure if this is correct but I thought that the banjo bolts were somewhat hardened. I bought a 10-pack of 1/16 in drills from H-F the other day for $2. I do not know how many it would take to drill the hole that Brent suggested. I might try it on a car where I had not rebuilt the rear end and replaced the seals.


Vic
 
BRENT in 10-uh-C said:
however if someone feels compelled to add one, then remove one of the axle housing to diff. housing bolts at the top and drill a 1/16th inch hole thru the middle in the center, and re-install the bolt. That would give it a place to vent without a noticible alteration.
Click to expand...

No no... That will spit out oil. Oil slings all over inside the banjo. Any vent would have to be in the axle tube, with a floating cap to keep debris and water out. Also, all of them that I have taken apart always had a gasket between the torque tube and pumpkin. Lots of oil in that area too.
 
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