Info needed: Transfer case vent

[Grant Bowker]

A. It would be presumptuous for me to claim to be an expert
B. I suspect the simpler vent (a loose fitting cap pinned onto the vent tube) was a case of simplify to cut production time and cost while maintaining most (some?) of the dirt protection capacity of the damaged version you have
C. It is possible to use the vent caps sold for Chevrolet 235 CID valve covers to fabricate a passable replacement for the damaged transfer case vent. My process is: uncrimp the perimeter of the damaged dome to remove the perforated flat panel (and the filter medium if possible), braze/weld/solder the recovered flat panel to the recovered (or a new replacement) pipe that threads into the transfer case, reinstall the filter medium into the dome and crimp the edge onto the flat disc. If the filter medium isn't recoverable, consider usiing metal mesh from a pot scrubber (also sold as pest control https://www.leevalley.com/en-ca/shop...copper-blocker).

[Grant Bowker]

More images to show how the pipe core was facricated . Basically off the shelf black iron pipe nipple, cut in half to give two pre-threaded stubs, turned down slightly to let a drilled out nut be slid onto the pipe, brazed together then the disc drilled/cut/filed from flat sheet added.

[Grant Bowker]

more images

[Jordan Baker]

There were two different vents used.

Please see attached GM Service Information Bulletin B29, Item 64 from December 12,1942

The early one was simply a pipe with a cap on it held on by a cotter pin "Fig2". The second version was the air cleaner type "Fig2".

These were introduced into production starting at serial number 1844332070.

[Barry Churcher]

Excellent job Grant.
Barry

[Paul Edwards]

GRANT! BRILLIANT!

Took the opportunity to photograph my own tranny today, it appears to be the early version (pipe/cap/cotter pin fig2) type, the vent exits vertically, hence why the air cleaner type had been butchered to fit under the cross rail. The air cleaner one would appear to exit at 45 degree slant.

Am I reading this bulletin correct, ie: the air cleaner type superseded the simple pipe/cap/cotter pin fig 2 type?

If so and all I need is the simple version then I recall there's one of these vents on the Jeep tranny, I wonder whether this wound fit?

Cheers,


Paul

[rob love]

I sounds like the air cleaner type was a product improvement, and that is was to be retrofitted onto the earlier transfer cases to replace the simple tube and cap. But in all seriousness, for the miles any of us will put onto our vehicles, nor the dirt we will subject them to, the nipple and cap would likely be fine.

If you are talking about the little nipple and cap on the jeep transfer cases, they are normally spring loaded onto a little check valve which will build up pressure to about 3 or 4 psi before reliving the pressure. They are usually 1/8 npt thread so would be pretty small for this application. However, with some bushings, it would work fine. The same nipple was used on the M35 deuce (and a thousand other vehicles) for that large transfer case for the last 60 years.

Edited to add: I had to look up the early Jeep transfer case breather and just saw that some indeed are a nipple with small cap retained b a cotter pin. But some sources are showing the pressurized cap which is more what I am used to. Someone with a WW2 Jeep will have to confirm if the nipple and cap type is 1/8 NPT.