Fj40 Knuckle Seal Problem? Front Drum Brake Grease Discovered. (Images) (1 Viewer)

[Ackcruisers]

Can someone please confirm I need a knuckle/gasket rebuild kit? My 1976 FJ40 is from Colombia so it has front drum brakes as shown.

Experienced brake pulling to left so removed front passenger side brake drum and discovered loads of grease sitting on top of brake shoes.

What seal specifically failed?

Also, experiencing the drivers side locking hub moves from “free” position to “locked” on its own when driving after a few miles. I’m sure this is not correlated but wanted to mention it

The axels were allegedly rebuilt before I bought the truck.

 

[fjc-man]

I’ve seen posts on here where individuals say replacing the axle seals with the marlin seals is the answer, but I think doing the SST centering tool measurements would assure they are centered in the seal and the right preload on the trunnion bearings. Really who knows what the last guy did.

 

[brian]

I'm trying to figure out how you could even have grease or gear oil there.
The spindle fastens to the knuckle and has a gasket. And i thought the backing plate is out side of the spindle yet.
This looks to me like the seal on the wheel bearing hub has parted ways.

 

[3_puppies]

X2 to what @brian said above, wheel seal issue.

 

[fjc-man]

Even though this is not a locking hub in this picture, I could see how moly grease mixed with gear oil could work it’s way past #24 and end up in the drum.

 

[fjc-man]

Oh, and then past#15. The wheel bearing seal

 

[fjc-man]

Yeah, that is a really early diagram. See the ball and claw axle?

 

[Ackcruisers]

I'm trying to figure out how you could even have grease or gear oil there.
The spindle fastens to the knuckle and has a gasket. And i thought the backing plate is out side of the spindle yet.
This looks to me like the seal on the wheel bearing hub has parted ways.

Where is the seal on the wheel bearing hub?

In the below diagram, the only oil seal is shown in blue circle. If anyone has exploded view that shows the seal or can point me to where in the 1975 chassis/body FSM let me know.

Haynes shows #20 ‘oil seal‘ and #21’hub inner bearing‘.

 

[brian]

They do not show it in the front axle section. The rear axle section is before the front, instructions for a full float rear apply to the front bearing hub assembly as well.

 

[Ackcruisers]

That explains it. Thanks @brian appreciate the help and for posting the FSM pages. This will derail my 4 speed /tcase upgrade progress. I’m ordering the Toyota front axel hub seal #90311-62001. Link here. Image below with seal in yellow circle. Once the hub is off I’ll inspect bearings.

 

[brian]

Aught to get a new star washer as well.

 

[fjc-man]

I don’t think anybody packs their wheel bearings with moly grease, and that’s what appears to be on the backing plate and shoes in the OP’s pictures.

 

[brian]

I don’t think anybody packs their wheel bearings with moly grease, and that’s what appears to be on the backing plate and shoes in the OP’s pictures.

"A" for effort, but for your theory to work, 4 seals would need to fail.....one of which is the bearing hub seal...and you would expect to see the standard goop on the back side of the backing plate, around the ball of the axle tube.

 

[fjc-man]

Agreed, we’ll see what the autopsy reveals.

 

[3_puppies]

I don’t think anybody packs their wheel bearings with moly grease, and that’s what appears to be on the backing plate and shoes in the OP’s pictures.

this rig is from south America, no telling what was done to it down there. best bet would be to just go thru both sides all the way.
for me it is not worth re-using the bearings, buy a complete knuckle kit for under $200 and just replace it all.
using Marlin inner seals

 

[Ackcruisers]

this rig is from south America, no telling what was done to it down there. best bet would be to just go thru both sides all the way.
for me it is not worth re-using the bearings, buy a complete knuckle kit for under $200 and just replace it all.
using Marlin inner seals

I’ll pull everything apart this week and post images of what the source of the problem was. From there, I’ll order the parts which may very well be a complete kit.

 

[fjc-man]

@cruiseroutfitters will have everything you’ll need.

 

[Ackcruisers]

There was movement of the locking hub up and down and side to side. Removed the unknown brand name free wheel/lock hub. Gear oil grease combination appeared to drip out. Posting video of the movement of the 30 spline axel.



Ordered the wrong size hub socket from Cruiser Outfitters 54mm vs 56mm needed so cannot go deeper until socket arrives.

My locking hubs do not have a retaining clip.. they also only measure 60mm. Can anyone recommend a better locking hub that will fit my set up? (drum brake, 30 spline).

 

[brian]

that's not the locking hub that is flopping around......that's the end of the axle.....and it will have play when the hub or drive plate is removed.

so there was no snap ring in the groove near the the end of the axle that needed to be removed before the locking hub body slid off the axle?

 

[Ackcruisers]

that's not the locking hub that is flopping around......that's the end of the axle.....and it will have play when the hub or drive plate is removed.

so there was no snap ring in the groove near the the end of the axle that needed to be removed before the locking hub body slid off the axle?

Yes. No snap ring on the end of the axle. I was able to slide the locking hub right off. There are two snap rings on the locking hub itself as shown.