Front Axle Leak - Both Sides (1 Viewer)

[brooklyn]

Pulling out the FJ40 this morning and noticed a leak at both front tires today - oil is dripping off the grease zirks. Haven't done much investigating, but pondering why both sides would start to leak at the same time and almost at the same rate. Do these symptoms indicate new axle seals are required? If so, any suggestions on what kit/vendor?

Trying to do a bit researching before getting into it!

 

[Malleus]

Zerk fittings are one way valves. They can't leak unless they've failed. I'd try to clean those areas with degreaser and see what develops overnight. That'll tell you where you need to focus the repair effort.

 

[charliemeyer007]

Wash the areas good with brake clean - check every hour to see where the leak is coming from.

Great advice "The trick to success is making sure you're solving the right problem"
Goes well with, if it ain't broke don't fix it.

 

[SteveH]

Those are not zerks - they are studs, covered with so much grunge you can't determine what they are. Anyway - you must check your front axle vent, as a clogged vent (and the crappy factory design) will pressurize the axle and cause leaks such as this.

What I have done (and there are other methods) is to simply pry off the floating axle vent cap (the part that wiggles) with a screwdriver, remove the spring and rubber disk, and slide on a 3' section of 3/8" fuel line over the remaining nipple that projects from the axle. Clamp it with an appropriate hose clamp, and run the hose well up high into the engine compartment where it's not exposed to wheel splash. Push a fuel filter into the end of the hose, if you like.

The reason the factory design is poor is that the rubber disk gets coated with gear oil, and then effectively glues itself to the vent, and the axle can no longer breathe properly. This can cause pinion seal leaks, too.

After all this, wipe down the entire knuckle area with a cloth and then watch for leaks. Your birfield cavities may now be full of birfield soup, and the knuckles will simply weep oil until you completely repack the front axle.

Get a front axle manual ($OR sells one) and read up on the entire axle.

 

[1969FJ]

Completely reseal the whole axle. A great learning experience and when finished, will last another long period.

 

[brooklyn]

Completely reseal the whole axle. A great learning experience and when finished, will last another long period.

@SteveH thanks for the detailed approach - will let you know how it works out.

@1969FJ - hoping to postpone until winter if possible…fingers crossed!

 

[peesalot]

thats what happens when they sit and the grease separates.

 

[brooklyn]

Started the disassembly - have decided on a complete knuckle rebuild in my very small garage. I am hoping when I pull the axle I will have enough room on each side - don't know what I will do if i don't!

 

[RevISK]

The drivers side one is about 4’ long, so be sure you have plenty of room to remove it (and the other, shorter side as well) otherwise you’ll be cutting holes in your walls the get them out.

 

[sogncab]

thats what happens when they sit and the grease separates.

That's exactly what my thought was

 

[fjc-man]

Put a floor jack under the front cross member and “steer” it away from the side you’re pulling the axle from.

 

[peesalot]

You got plenty of room, door lines up with driver side and pass side is short.

 

[brooklyn]

Put a floor jack under the front cross member and “steer” it away from the side you’re pulling the axle from.

Thanks for the suggestion—hopefully I don’t have to go that route. That’s a balancing act I would like to avoid!

 

[brooklyn]

Need to pick up the grease for the bearings and to pack the knuckle and wondering where people are buying the grease on what is the preferred brand. Also, how much will I need for both sides.

 

[RevISK]

Need to pick up the grease for the bearings and to pack the knuckle and wondering where people are buying the grease on what is the preferred brand. Also, how much will I need for both sides.

Bearing grease for the bearings, spindle and what not. Moly grease for the knuckles, birfs and what not.

Two tubs of moly and a tub of bearing should get you by.

Take your rig to the car wash and get as much crud off the outside as possible, a small but helpful step in the amount of mess you’ll be dealing with.

Nitrile gloves

Shop paper towels (a couple boxes)

I used egg crates for bolt assortment

Also used my son’s rock tumbler and mineral spirits to clean all the small bits.

Torque wrench

Small and medium boxes to catch all the sh!t that you’ll be cleaning off.

Dawn soap for your hands and parts cleaning

Watch plenty of videos and have your FSM handy.

Beer, lots of beer.

Hit me up if you need help in real time.

 

[RevISK]

Make sure you have all of your parts handy:

Seals
Gaskets
Rtv
Spare bolts
Bearings (reunion and wheel/axle)
And so on

 

[RevISK]

Make sure you have all of your parts handy:

Seals
Gaskets
Rtv
Spare bolts
Bearings (reunion and wheel/axle)
And so on

“Trunion” bearings…
Stupid autocorrect

 

[brooklyn]

Question regarding knuckle bearings. I purchased a knuckle service kit that was designed for 79-85 Pickup/4Runner, 75-90 FJ40, FJ55, FJ60 & FJ62. When I compare the bearing the sizes look different. Included pictures, and the knuckle with the "old" bearing. The existing races look good, so I was planning on just using the new bearings.
Suggestions...

 

[RevISK]

The new bearings came with new races, yeah?

 

[RevISK]

Replace with new races while you’re in there. It’s not hard. Just make sure the seats are free of debris and really clean. Coat the new race with a little grease.