Front hub leak

[dfarley4504]

Hey all.
This oil slinging out of my front hub is ultimately coming from the oil in the axle filled at the front differential, correct?

 

[DeskJock]

Hey all.
This oil slinging out of my front hub is ultimately coming from the oil in the axle filled at the front differential, correct?

View attachment 3715113

Could be heated grease from the knuckle too.

 

[pb4ugo]

Your probably right. The inner axle seal has probably failed. Knuckle service is normal maintenance item. What's it look like on the backside?

 

[dfarley4504]

Your probably right. The inner axle seal has probably failed. Knuckle service is normal maintenance item. What's it look like on the backside?

Here’s a pic of the inside.
The highlighted area is “damp” with oil, not quite wet, and certainly not a drip.

 

[dazerb]

With my seals failing, it was far messier on the back. Never saw any oil flinging anywhere...
Until i put a little rust tx on the back of my old hubcaps. That little lip on the back traps water

 

[charliemeyer007]

My 72 was born without hubs for like the first 60,000 miles. Rebuilt the front end. The flats on the inner axle had two small groves worn in the by the seals. New seals didn't fix the issue for long. Next time I'm going to weld them if I can't get like a Speedy Sleeve fix.

 

[Grayscale]

Leaking caliper piston? If so, that truck is not safe for traffic. Not viscous enough to be axle oil seals?

 

[dfarley4504]

Leaking caliper piston? If so, that truck is not safe for traffic. Not viscous enough to be axle oil seals?

Brake caliper piston? No sir.

 

[MDH33]

Axle seal gave up. but I always do everything while I'm in there. Seals, bearings, measure for shims, etc.

 

[Grayscale]

The inboard felts on the knuckle seem to be somewhat holding gear-oil despite the apparent sweating grease. Mine have always leaked there, and I don't see an actual drop of oil in your photo. Either oil or hydraulic fluid, it sees odd to having the outboard-side of the wheel coated with something, What if that mess finds its way to the braking surface? The rust on the outboard side of the rotor appears much darker, wetter, than the other.

Did you pull the hub cap and wheel to see that the rotor isn't getting oily?

A long time ago, I nearly rolled a brake-drum 40, tipped-over on two wheels, for having hydraulic fluid on the braking surface up front. I slammed on the brake, and the steering wheel turned itself all the way to one side.

 

[dfarley4504]

Haven’t pulled the wheel yet.
Let’s see if I understand this.
If the fluid is prominent in-board of the wheel, it’s from the axle, out-board is grease from the hub?

 

[Grayscale]

Looking at the section-drawing, it is possible that an axle-inner-seal leak could leak oil into the inside of the knuckle, or as far outboard as the Warn locking mechanism on the front of the hub. The green is hydraulic fluid. The brown is differential oil. The knuckle felt seal is what I consider most vulnerable to a leak if the axle inner seal is bad, but it could possibly make its way to the outboard side of the hub along the axle shaft, if the hub gasket is no good.

Once you remove the wheel, it should be obvious exactly how the front of the wheel is getting wet, either from the hub leaking oil, or the rotor getting wet from brake fluid.

As a side-note, you could have a slight leak on the axle inner seal, as well as needing a brake caliper service.

 

[dfarley4504]

Looking at the section-drawing, it is possible that an axle-inner-seal leak could leak oil into the inside of the knuckle, or as far outboard as the Warn locking mechanism on the front of the hub. The green is hydraulic fluid. The brown is differential oil. The knuckle felt seal is what I consider most vulnerable to a leak if the axle inner seal is bad, but it could possibly make its way to the outboard side of the hub along the axle shaft, if the hub gasket is no good.

Once you remove the wheel, it should be obvious exactly how the front of the wheel is getting wet, either from the hub leaking oil, or the rotor getting wet from brake fluid.

View attachment 3715963
As a side-note, you could have a slight leak on the axle inner seal, as well as needing a brake caliper service.

My truck is a 72 model with aftermarket disc (JT Outfitters).
Is this drawing of the hub the same?

 

[Grayscale]

The hub is drawn different between disk and drum brakes. The drum is oriented outboard of the hub, a disk brake rotor is inboard of the hub. The backing plate, which holds the drum brake wheel cylinders, is replaced with a knuckle cap to hold the caliper, on the JT kit. The seals are the same for the knuckle from '58 to '90. The seals, hub, spindle, and hub locking mechanism are all specific, from what I can tell, however, the function is essentially identical. I'd imagine that you have the drum brake spindle and hub, with those bearings, seals, and locking nut which requires a different socket, iirc. Front Disc Brake Conversion Kit for Toyota Land Cruiser FJ40 FJ45 FJ55 Drums – JT Outfitters - https://www.jtoutfitters.com/product/front-disc-brake-kit-for-toyota-land-cruiser-fj40-fj45-fj55-drums/

 

[dfarley4504]

The hub is drawn different between disk and drum brakes. The drum is oriented outboard of the hub, a disk brake rotor is inboard of the hub. The backing plate, which holds the drum brake wheel cylinders, is replaced with a knuckle cap to hold the caliper, on the JT kit. The seals are the same for the knuckle from '58 to '90. The seals, hub, spindle, and hub locking mechanism are all specific, from what I can tell, however, the function is essentially identical. I'd imagine that you have the drum brake spindle and hub, with those bearings, seals, and locking nut which requires a different socket, iirc. Front Disc Brake Conversion Kit for Toyota Land Cruiser FJ40 FJ45 FJ55 Drums – JT Outfitters - https://www.jtoutfitters.com/product/front-disc-brake-kit-for-toyota-land-cruiser-fj40-fj45-fj55-drums/

Cool. Thanks a lot!