Replaced Axle Vents

[M35A2-AZ]

I took off my axle vents and put in some piping and hooked them all up to a central vent under the hood up by the motor.

Our road is very dusty, not sure if the dust did it or not, but one of the vents stopped working and blew out a seal and washed out all the grease in the bearings.

 

[rrrr]

Is that a 939 series truck ?

I've been thinking about doing that with my 932a1. I plan to have a little fun with the truck !

What type of air line did you use ?

 

[dpms101]

Yep good idea , I used to do the same on my jeeps , does help with water getting in

 

[M35A2-AZ]

Yes it is a M923A1. I used parts from Parker with plastic tubbing, like air line tubbing.
I used 5/16" line. After I got the parts I found some fitting that are 1/8" pipe and 3/8" tubing.
So I would of used 3/8" tubbing, but I think the 5/16" will work fine.
It took about 48' of tubing.

 

[wsucougarx]

Great idea my friend. Chalking this up for my "soon to be" 923 project list. Just need to find a 923 first

 

[M35A2-AZ]

Thanks!!
I think I am going to do it to all my truck at so point.

 

[73m819]

on the end of the vent line, install a cheap inline gas filter, this will keep the dust out but allow the vents to breath

 

[groundog]

i re-placed my vents on my 931---removed fill plug to check oil in rears and air came out-so i knew i was in trouble---replaced two axle seals---those brake drums are heavy

 

[73m819]

i re-placed my vents on my 931---removed fill plug to check oil in rears and air came out-so i knew i was in trouble---replaced two axle seals---those brake drums are heavy

YEP, you can replace ALL FIVE vents with a fittings and vaccum hose faster then replacing ONE seal, I would add the master cylinder to the vent system, if not adding then give it it's own line

 

[peashooter]

Great idea thanks for sharing

 

[Hammer]

I prefer to run it into the air intake, so it gets filtered air.
If you want to run a separate filter, I like the little K&N oil breather filters. They are cheap, and with the oil coating, really help keep out more moisture.

 

[steelandcanvas]

I prefer to run it into the air intake, so it gets filtered air.
If you want to run a separate filter, I like the little K&N oil breather filters. They are cheap, and with the oil coating, really help keep out more moisture.

What are you getting filtered air to? Don't the axle vents expell air pressure built up in the transfer case, tranny, and axles? I guess I just don't understand the need for a filter, since the air is coming out of the system.

 

[73m819]

the housings BREATH, when hot create pressure, as thay cool thay create a minor vacuum

 

[Hammer]

What are you getting filtered air to? Don't the axle vents expell air pressure built up in the transfer case, tranny, and axles? I guess I just don't understand the need for a filter, since the air is coming out of the system.

The air pressure changes and bascially breathes in and out based on the change in temperature.
The filter is to keep any foreign materials from getting sucked in.
Heck, I have seen the system as a sealed system and using an expanding bellows to accommodate for the pressure changes, but I don't really trust those enough.

 

[steelandcanvas]

the housings BREATH, when hot create pressure, as thay cool thay create a minor vacuum

The air pressure changes and bascially breathes in and out based on the change in temperature.
The filter is to keep any foreign materials from getting sucked in.
Heck, I have seen the system as a sealed system and using an expanding bellows to accommodate for the pressure changes, but I don't really trust those enough.

Thanks Guys, I knew the pressure escaped, but didn't know a vacuum could be created also. I learned something today.

 

[plym49]

Thanks Guys, I knew the pressure escaped, but didn't know a vacuum could be created also. I learned something today.

Absolutely so. Say you are running down the road. Parts are hot inside your axles and gearboxes; pressures are up. Now you ford something deep enough to immerse that stuff in water. The quenching causes rapid cooling, pressures drop, and air or water can get sucked right in. That's the idea behind the bearing buddies used on boat trailers. Prevents water from getting sucked into the trailer wheel bearings by pressurizing them with grease.

 

[Clayshootr]

Yes it is a M923A1. I used parts from Parker with plastic tubbing, like air line tubbing.
I used 5/16" line. After I got the parts I found some fitting that are 1/8" pipe and 3/8" tubing.
So I would of used 3/8" tubbing, but I think the 5/16" will work fine.
It took about 48' of tubing.

So it is 1/8" pipe that will screw into the axle housing? I took the vent plug out of my 931 rear axle because of this same problem. Every time I took the check plug out the diff was pressurized, and oil is leaking out the front pinion seal.

 

[M35A2-AZ]

So it is 1/8" pipe that will screw into the axle housing? I took the vent plug out of my 931 rear axle because of this same problem. Every time I took the check plug out the diff was pressurized, and oil is leaking out the front pinion seal.

Yes they are 1/8 pipe. One of my axles started leaking and I took off the fill plug and there was a burst of air. Same thing happen to my M35A2.
I got 50' of tubing and fittings and it cost about $45 from Parker.

 

[quickfarms]

I have used the k&n filters in the past for the axles on an off road toy and they worked great

 

[M35A2-AZ]

I have used the k&n filters in the past for the axles on an off road toy and they worked great

Do you have a p/n of the K&N filter you have used for axle vents?