Axle vent issue and solution

CJ3FLYR · 07-31-2005, 09:10 PM

While performing a reconnaissance mission for the installation of my PMLI extra capacity differential cover I made a disturbing discovery. The design of the rear axle vent was unacceptable (to me) due to the possibility of water intrusion while 4 wheeling or at a boat ramp. The factory vent is basically a check valve that vents pressure to atmosphere (See Fig. 1). This type of vent invariably fails at some point in time and could allow the rear axle to become contaminated. A second problem, IMHO, is that when the axle cools with this type of vent it holds a vacuum inside the axle. This vacuum pulls in on the seals and when you resume driving the seals are being pulled extra hard into the shafts possibly causing extra seal wear. Now there are some types of seals that require pressure or vacuum to work, these are not they.

I consulted the Mickey Mouse engineering handbook and combined it with the “I slept in a Holiday Inn Express” attitude and came up with the following: First was a trip to Ace Hardware and the AutoZone. I purchased a 1/8MPT thread to hose adapter from the ACE. Much to my surprise that is the correct size. Next it was off to the AutoZone for six feet of 5/16 fuel line and a cheap fuel filter (no check valve style). See fig2. I chose to put a filter on there as a deterrent for dirt, dust and debris from getting into the vent tube and it was cheap so what the heck.

I then removed the stock breather and installed the adapter to the axle with a dab of sealant on the threads. I then clamped and routed the hose up into the right, rear taillight area and used some wire ties to keep it in place. Note; be sure to leave plenty of extra line between the axle and your first tie. There needs to be enough to allow for axle movement, especially extension. Fig 6 shows a good place run a tie in the taillight area.

The whole job was relatively quick, easy and well worth it for my needs. I did have a quick look at the front axle vent and it appears to be good. I’m pretty sure it’s the long tube that dumps right below the engine air filter box. I still need to figure out the transmission vent and transfer case vent…

Hope this was of interest and to the moderators, if this should have been put in the how to please move it as you see fit.

CJ3FLYR · 07-31-2005, 09:11 PM

The rest of the pics

CaptFDU · 07-31-2005, 09:46 PM

Looks like my next project. Thanks!

Armada · 08-01-2005, 12:41 AM

Nice catch there CJ3! I have to look at my Armada now to see how the vent tubes are set up. Probably the same. Check valves are not the way to go. Thanks for noticing.

I offroad with a CJ5 and use on both differentials the same long tube remote fuel filter system you have installed. Some guys use little tiny K&N's on the end of the lines, but that is overkill.

JefeCinco · 08-01-2005, 06:49 AM

Well, I'm glad you guys have been able to teach the Nissan engineers how to vent a differential properly.

I don't off road so won't even say anything about it. But, I do a lot of fishing and boat launching.

If it's necessay for you to back into the water so far when at the ramp as to submerge the differential you have a problem. As I'm certain you know how best to deal with a launch ramp it's clear that the ramp design is bad and there is nothing wrong with your technique. I'd look for another ramp.

QShip · 08-01-2005, 06:59 AM

Thanks for the write up! That's a nice "need to know"!

CJ3FLYR · 08-01-2005, 09:06 AM

Nice feedback guys, thank-you

. I have learned so much from this forum about Titans that my ownership exp. has been dramitically enhanced. All the info on helper springs, A/C TSB's, etc. (and don't forget the brakes!) has taken what could be very frustrating things and put them in the 'no issue' catagory. The power of knowledge has made all of this fun, a mission, whatever. It's allowed me to derive max enjoyment from my very cool truck

. So thanks to all of you!

**HudsonValleyTitan** · 08-01-2005, 09:12 AM

Why not a closed accordian style set-up like the last Frontier/Xterra had? It allows for expanding and contracting but is still closed to dirt and water.

CJ3FLYR · 08-01-2005, 09:24 AM

That'd work too, I have never seen one and much like the Japanese automakers of the 60's, 70's and 80's I'm not particularly creative but good at emulating/improving on existing stuff.

Maybe a cheap siphon with one end blocked... Hmmm.

Justintoxicated · 10-04-2006, 05:46 PM

Great now I read this...Afer my rear axle seals are leaking. Will this vent void the warranty? I'm having a new axle installed next week! Might be time to rig something up...

Bookmarked!

kartman · 10-04-2006, 08:42 PM

Quote:

Originally Posted by Justintoxicated

Great now I read this...Afer my rear axle seals are leaking. Will this vent void the warranty? I'm having a new axle installed next week! Might be time to rig something up...

Bookmarked!

It can, talk to your service manager. Mine does not care but others will.

Burly · 10-04-2006, 09:44 PM

Quote:

Originally Posted by Justintoxicated

Great now I read this...Afer my rear axle seals are leaking. Will this vent void the warranty? I'm having a new axle installed next week! Might be time to rig something up...

Bookmarked!

I am going to do the same the day my truck comes home with the new axle!

bestatchess · 03-19-2007, 12:11 PM

If you have done this mod, please post your results. (e.g., satisfactory, blows excessive oil out vent tube, etc.)

Also, has anybody who has done this mod had a rear axle seal leak?

54warrior · 03-19-2007, 12:38 PM

Void the warranty, don't see how, they may question the filter and that would be it. If anything it's venting more air, don't see why it would be an issue.

kartman · 03-20-2007, 07:57 PM

Quote:

Originally Posted by bestatchess

If you have done this mod, please post your results. (e.g., satisfactory, blows excessive oil out vent tube, etc.)

Also, has anybody who has done this mod had a rear axle seal leak?

I blew 2 seals before the mod, none since and no other issues.