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

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

post #9, 2nd picture, figure 5-28, someone forgot to install that seal or installed it wrong, my guess is it is not there. Why is molly grease not for wb ? It seems to work fine if you trap it in there with some old drum brake axle grease as a topper.
 
And, they used 5/16" screws on the hub face? And, the springs were assembled wrong on the brake shoes.
The locking hub face are M8 1.25 and smaller bolts M6 1.0. I know the wheel cylinders were installed with the dial on bumper facing side on top (should have been on bottom for ease of adjustment access). I will look at FSM before I reassemble everything to determine what they did wrong on brake shoe springs.
 
post #9, 2nd picture, figure 5-28, someone forgot to install that seal or installed it wrong, my guess is it is not there. Why is molly grease not for wb ? It seems to work fine if you trap it in there with some old drum brake axle grease as a topper.
In the figure 5-30 in post #9 it says pack grease Into hub wheel bearings.
 
I was able to back off the odd 56mm nut with a cold chisel to get the hub off. It appears the problem is in fact a poorly installed seal. The images below show the front axel hub seal with wear and part of the rubber ring is no longer attached to the seal. Also, it appears the copper color of the seal is scraped off. This may be caused from installation or movement. And for the record, there was grease inside the hub.
9847C7C8-F2A5-4350-9213-FAD935F24E7A.jpeg

7967B1C5-348F-4C32-9FD1-0C01106E261B.jpeg

122D249E-2A80-46BB-8375-336EB12C73EF.jpeg

All bearings look new.
 
Metric screws never have the radial lines on their face, IIAC. I'm thinking that those are 5/16-18, which is so close to 8x1.5mm that it takes someone who has already made that mistake, like myself, to know the difference.

Do those screws fit well into either a 12mm or 13mm socket? I'd bet that they fit better with a 1/2-inch.

One of the brake return springs is supposed to be on the back side of the pad flange.
 
So somebody packed the hub and wheel bearings with moly grease, damaged the grease seal on installation and that the source of the moly grease all over the brake parts.
 
So somebody packed the hub and wheel bearings with moly grease, damaged the grease seal on installation and that the source of the moly grease all over the brake parts.
The FSM says to pack MP into the hub and bearings (including page below). Still not clear what caused the seal to be compromised. There was movement on the hub before removing 56mm nut. Also, there was no retaining clip on end of axel. After the axel nut there was a ring that screwed onto spindle and it had 4 holes in it with 2 small screws (not sure what this part is). As shown in image below, the sequence was nut, washer then ring. I’m ordering a Spindle Nut Kit from Cruiser Outfitters part#FA60011K link here as well as retaining clips to put everything back on correctly.

I believe this was the problem but still not sure how gear oil gets past the other seal?

A0CC3005-3329-498B-8E4B-E64C86B6FB23.jpeg

2E3BDE0F-7635-40F3-A734-AECFDA9A5326.jpeg
 
close up pix of the spindle.....one pic shows what might be wear from a spun bearing.
Thanks for seeing that and for the accurate hub seal diagnostics. Below is a very close up shot of spindle. There does appear to be some wear from outside bearing.
6D5539AF-DF54-4EB6-B0F9-96D5F4569B71.jpeg
 
Multi purpose grease for the wheel bearings, moly grease in the knuckle for the trunnion bearings and the birfield joint. Looks like you might have to shop for new spindles as well.
 
Multi purpose grease for the wheel bearings, moly grease in the knuckle for the trunnion bearings and the birfield joint. Looks like you might have to shop for new spindles as well.
I’ll have to research what the differences are with multi purpose vs moly grease. Wouldn’t by the definition of ‘multi purpose’ allow it to be used everywhere?
The spindle just has some discoloration on it no measurable wear.
 
I’ll have to research what the differences are with multi purpose vs moly grease. Wouldn’t by the definition of ‘multi purpose’ allow it to be used everywhere?
The spindle just has some discoloration on it no measurable wear.


generally Lithium based grease in wheel bearings, moly in the birf and ujoints
.
 
Base on the pics of the order of your nut, washer and lock nut, imo, that's the wrong order and your possibly missing 1 washer. It appears you have some sort of a aftermarket Aisin style lock out which probably came with the round locknut and missing washer. Dizzy may be correct about the grade 5 markings on the head of the bolts and the bolts maybe SAE threads. As for 8mm or 5/16 heads, they are essentially the same. Anyways, I have a set of warn lockouts that use a similar locknut except it uses allen head set screws instead of machine screws. There should be the flat washer installed 1st with the internal tab, then the stk hex nut, then another washer(missing) with a bunch of holes in it and has an internal tab on it to go into the notch of the spindle, then the round lock nut. The round nut is tightened with a spanner wrench or a punch using the 2 extra hole in in. Once that nut is tighten then you tighten the 2 screws which engage in to the holes of the missing washer. Your outer bearing may have been loose because the washer with the internal tab was not against the bearing, instead the hex nut was. The aftermarket lock out may not allow you be able to use the 2nd stk hex nut you ordered because of clearance between the hub and lockout.
 
Metric screws never have the radial lines on their face, IIAC. I'm thinking that those are 5/16-18, which is so close to 8x1.5mm that it takes someone who has already made that mistake, like myself, to know the difference.

Do those screws fit well into either a 12mm or 13mm socket? I'd bet that they fit better with a 1/2-inch.

One of the brake return springs is supposed to be on the back side of the pad flange.
I actually tried the 5/16-18 and it would not fit into my thread sizing tool. The 1/2 inch socket was way too tight but 13mm socket fit well. I will still buy different screws. These locking hubs are cheap. I’m going to upgrade but am stumped on long birfield vs short. What do I have?
281BF9A5-2D47-455F-8E2E-3885DAE658AE.jpeg

8A99D52D-8A24-40F6-9267-D3F4BABE23F6.jpeg
 
Base on the pics of the order of your nut, washer and lock nut, imo, that's the wrong order and your possibly missing 1 washer. It appears you have some sort of a aftermarket Aisin style lock out which probably came with the round locknut and missing washer. Dizzy may be correct about the grade 5 markings on the head of the bolts and the bolts maybe SAE threads. As for 8mm or 5/16 heads, they are essentially the same. Anyways, I have a set of warn lockouts that use a similar locknut except it uses allen head set screws instead of machine screws. There should be the flat washer installed 1st with the internal tab, then the stk hex nut, then another washer(missing) with a bunch of holes in it and has an internal tab on it to go into the notch of the spindle, then the round lock nut. The round nut is tightened with a spanner wrench or a punch using the 2 extra hole in in. Once that nut is tighten then you tighten the 2 screws which engage in to the holes of the missing washer. Your outer bearing may have been loose because the washer with the internal tab was not against the bearing, instead the hex nut was. The aftermarket lock out may not allow you be able to use the 2nd stk hex nut you ordered because of clearance between the hub and lockout.
This is very helpful. Below is an update to the sequence of washers and nut. The locking hubs are aftermarket for sure and if anyone can recommend a good replacement let me know. Cruiser Outfitters has Warn that will work with either longer birfield or short and 30 spline.
BBFF1212-BD5A-4B45-8634-B67378795DA9.jpeg

4B5D07D8-9E5A-4AE3-AA88-15F556883C15.jpeg
 
This is very helpful. Below is an update to the sequence of washers and nut. The locking hubs are aftermarket for sure and if anyone can recommend a good replacement let me know. Cruiser Outfitters has Warn that will work with either longer birfield or short and 30 spline. View attachment 2436610
View attachment 2436611

So I was wrong, It looks like your missing the washer that goes against the bearing. According to your pics that looks like the correct order. I've always heard Aisin or ASCO hubs are supposed to be the strongest hubs. There were long body and short body hubs. Toyota dealers on 1976-78 installed Warn 2 piece which were probably long body, after that, they upgraded the birfields to short ones. . Look in FAQ's in this section, scroll down to frt ends, there's good info on lock outs and what works.
 
Moly-fortified wheel bearing grease is just typical Lithium-based wheel bearing grease with molybdenum sulfide added. Good rundown here on that, and other greases: Know-How Notes: Different Types Of Grease And Where To Use Them

I have used the Ford-Mercury moly wheel bearing grease for years on my FJ40 for almost everything. I typically use red grease for TREs, since they aren't exactly 'high speed' ;)
 

Users who are viewing this thread

Back
Top Bottom