You can get to the transfer case vent easily by removing the access cover on top of the "hump" under the seat.... there are only 2 screws holding the access cover on. The Transmission one I think you probably need to remove the hump in order to access. I recently replaced my vents with tubing and a breather (
see here). If you want to try reaching up from the bottom of the truck to find the trans vent, it will be right in FRONT of the shifter arm on the very top of the trans.
You can tee them together and run all up to the front but that increases your chance for all of the vents to get plugged if the hose kinks or something. I tee'd my rear axles but ran all the other vents to the front (1-rear axles, 1-front axle, 1-transfercase, 1-transmission). Ideally you would have a separate line for each, but tee's are probably fine if you route the tubing properly so it wont kink. I'd probably go with a little larger tubing if you tee it all just to reduce the chance of something plugging it somehow.
I really like your axle vent solution!
Anyway, my question is, in your third picture I can see you've capped off the top of the manifold, but
what did you place on the bottom of the manifold? I'm assuming it's some sort of filter just to help prevent crud from the engine compartment from going back into the axle vent lines, but it
looks like a piece of cork! (
Edit: After being on McMaster, I'm going to say that it is definitely an air tool muffler! But wouldn't mind the confirmation).
Maybe a help to others, and to check that I have all the right parts/fittings, I believe this would be the parts list(?):
(Note, this doesn't use a larger vent line even though the rear two axles would be tee'd together)
4 Port Manifold x1
4 Outlets for 1/4" Tube OD, 3/8 NPTF Inlet
http://www.mcmaster.com/#4785k21/=wmvwbe
Axle x3, Transmission, Transfer case breather fittings (5 total)
Straight Adapter for 1/4" Tube OD x 1/8 NPT Male
http://www.mcmaster.com/#5779k108/=wmwh1c
Push-to-Connect Tee Fitting x1
Tee for 1/4" Tube OD
http://www.mcmaster.com/#51495k134/=wmw4oc
Crack-Resistant Polyethylene Tubing, (probably the 50' or 100' depending on routing)
1/8" ID, 1/4" OD, 1/16" Wall Thickness, White
http://www.mcmaster.com/#5181k24/=wmw9b8
Manifold top plug x1:
3/8" Pipe Size, Hex Head Plug
http://www.mcmaster.com/#9151k73/=wmwch8
Manifold bottom filter x1:
Air tool muffler
Hex Style, 3/8 NPT Male, 23 Maximum scfm, 1-1/2" Height
http://www.mcmaster.com/#4450k3/=wmwkm4