FJ80 Front Axle Question (2 Viewers)

[NewToFJs]

1991 FJ80, a while back I had a shop who said they were experienced with Land Cruisers rebuild the front end -- axles, steering knuckles, maybe some other stuff, I don't remember.

The axles they used were aftermarket, they have two outboard grooves for a snap ring, I suppose for different applications, and a grease zerk in the end of the axle, which the stock axle did not have.

I've been pulling the pipe-thread plugs on the steering knuckles periodically and pumping in Moly grease per the owner's manual. Is it OK to use Moly grease for the zerks on the ends of the axle also?

I am assuming that the wheel bearings are lubricated by the oil in the front differential, like any other 4WD truck. Is this true?

Thank you.

 

[CharlieS]

Nope, grease lubricates the stuff in the knuckles, and gear oil lubricates the diff end. There are seals around the shaft to keep them separate.

 

[TheBussman]

yes use moly grease in the zerks, since you have those there is no need to put grease in where the pipe plugs are. The zerks do a better job at putting the fresh grease where it's needed most.

 

[mjosoba]

yes use moly grease in the zerks, since you have those there is no need to put grease in where the pipe plugs are. The zerks do a better job at putting the fresh grease where it's needed most.

Although you will likely still want to pull the plugs when you pump in the zerk to relieve pressure.

 

[NewToFJs]

yes use moly grease in the zerks, since you have those there is no need to put grease in where the pipe plugs are. The zerks do a better job at putting the fresh grease where it's needed most.

Thank you!

 

[JohnnyFish]

I remember this guy saying he leaves his axle seals out and adds extra diff oil so that the hubs are lubricated by 90 weight. Never heard that from anyone else.

https://www.youtube.com/@MadMatt4WD/videos

 

[mudgudgeon]

I remember this guy saying he leaves his axle seals out and adds extra diff oil so that the hubs are lubricated by 90 weight. Never heard that from anyone else.

https://www.youtube.com/@MadMatt4WD/videos

This will apply to the rear axle only. It's not entirely uncommon to do this with the rear axle.

It's not an option for the front axle as the knuckle felt wiper seals aren't an oil seal, just a dust seal

 

[greentruck]

Nope, grease lubricates the stuff in the knuckles, and gear oil lubricates the diff end. There are seals around the shaft to keep them separate.

And the moly goes in the middle. So there's 3 different lubes going on, which can be a little confusing if you're new to Land Cruisers.

Gear oil in the diff, then a seal that needs to be intact to avoid mixing the gear lube with the moly grease that bathes the Birfields in the trunnion boxes, then outside of all that are the wheel bearings that need to be lubed with hi-temp wheel bearing grease.

 

[jonheld]

Fwiw, I stopped using multiple greases years ago.

 

[Rusty Marlin]

Fwiw, I stopped using multiple greases years ago.

Jon, I believe this may be the only time I have ever disagreed w/ one of your posts.
As pertaining to greases: Roller element bearings should not get Moly EP grease as the moly will act to prevent rolling action and could induce sliding, which would destroy a roller bearing. This is why Moly EP is used in the Birfields, because while there are balls in a cage, they don't really roll, they are intended to slide. General purpose grease or wheel bearing grease is designed to float roller element bearings on a film while rolling and not slide.
All this to say, For optimal life of the various components, there really should be two different greases in the front axle assembly.

 

[mjosoba]

Fwiw, I stopped using multiple greases years ago.

Same. I’ve been using moly for everything on my various ‘Cruisers for a long time. I’d say it’s a safe bet it’s well over 100,000 miles.

 

[jonheld]

Roller element bearings should not get Moly EP grease as the moly will act to prevent rolling action and could induce sliding

Yea, I read that too. Fortunately, the underside of my truck is not a class 1 clean room. I have been using moly grease for everything on both my 91 and 97 for well over 20 years now with no issues whatsoever.
If you're more comfortable using and stocking multiple greases, then certainly do what you want. I'm just saying that it really isn't a deal breaker.

 

[Rusty Marlin]

I've gotta 1970 MIL (Army) report from Aberdeen that would pretty much make anyone swear off Moly grease for anything... but like the good Toyota fanboy I am, I'm still using it. LOL

 

[jonheld]

I've gotta 1970 MIL (Army) report from Aberdeen that would pretty much make anyone swear off Moly grease for anything... but like the good Toyota fanboy I am, I'm still using it. LOL

Greases and oils have come a long way in the last 54 years. There are several items in the Toyota FSM that are carryovers from the FJ40 days. I certainly follow the FSM, but certain items never got updated.

 

[mudgudgeon]

Greases and oils have come a long way in the last 54 years. There are several items in the Toyota FSM that are carryovers from the FJ40 days. I certainly follow the FSM, but certain items never got updated.

Also there's papers written about the use of moly grease in roller bearings.
No issue with moly content below 5%.

Any fresh grease is better than old dirty grease.

 

[baldilocks]

Valvoline Palladium is a readily available Moly fortified choice that can be applied to all points requiring grease.