Rear Differential Breather Installation

After reading of many members of the T4R forum relocating their differential breathers to avoid inevitable milky gear oil, I decided to give it a go. A little cheap insurance later on down the road can't hurt, and if nothing else, I got some good one on one time with the rig, getting to know a little more about her. I have a trail, and thus a locker. So a separate breather for that as well, because overkill. I decided to use the standard OEM Toyota front differential (2-way) breathers. Let's get into it:

Parts used:

14' Transmission oil cooler hose, 3/8"

Toyota part 90404-51319 (Union)

Toyota part 90930-03136 (Breathers) (x2)

Stainless steel hose clamp (x4)

Enough zip ties to hold it all together

Teflon tape

Sierra Nevada Torpedo IPA


I want the breathers to end up in the jack/tool compartment on the driver's side of the cargo area using an unused grommet in the cavity below the jack/tool mount. First step was to remove the tools/jack and drop the spare. I located the grommet, removed it and fed my lines through.

I stopped when I had a good loop in the compartment

Removed the stock 1-way valve, added some teflon tape to the new nipple and installed it on the rear differential

I then pulled the connector off of the e-locker breather hose, leaving the end exposed

Routed the lines from the fender to the axle along the fuel tank fill line

I left some wiggle room to account for suspension travel

I attached the hose ends to the installed nipple, and the end of the e-locker hose using the hose clamps. The e-locker hose that is attached fits into the new transmission cooler line loosely, but will clamp down with the hose clamp tightly. I used a zip tie on the e-locker line to keep it from moving around too much. Be sure to route away from the exhaust, too close might get a bit toasty.

I cut the line in the cargo area, and cut the OEM grommet plug to fit around the lines.

This is where things got a bit sideways. I spent the better part of an hour trying to seat the grommet plug in the hole to no success. I then took the rear fender bumper off to get a better look.

I decided to install the grommet plug from the outside. I cut the plug along the edge, and fit it around the lines. With a bit of soap, I was able to fit it in for a decently sealed fit. Hind sight, don't cut the plug, just remove the bumper edge first and feed from the outside. Done deal.

Install the breather valves on the hoses with hose clamps.

Zip tie the hoses into a spot that is convenient for you.

Reinstall the spare tire, put the jack/tools away, install the covers, finish your beer, done.

Now, to find a creek crossing...


Max SheehanComment