Cruiserdrew
On the way there
Sorry Hayes, that was not directed at you, it was directed at JG. I should have been more clear.
Civility is one of the hallmarks of IH8MUD, and it looks like the boss wants to keep it that way.
knuckle;is all that moly grease really needed?? (1 Viewer)
- Thread starter chapel gate
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Sorry Hayes, that was not directed at you, it was directed at JG. I should have been more clear.
Civility is one of the hallmarks of IH8MUD, and it looks like the boss wants to keep it that way.
I'll have to double check tonight, somehow I got lithium MP grease in my head lol.
chapel gate
GOLD Star
- Thread starter
- #43
doug, that makes perfect sense, its an "auxiliary" grease port if you like. a means of getting grease to the CV joint when grease is lost unexpectedly and a large amount of it, and for whatever reason a full repack cannot be done.
landrover actually developed an OME grease that solidified when the vehicle was not in motion.
"It's the wheel bearings that you don't want to use moly grease on as they are high speed and supposidly the moly will cause excessive (uneven??) wear."
i would of thought that the CV joint turns at a pretty high speed too. i allways thought bearing grease is used because its opperates well under high pressures
landrover actually developed an OME grease that solidified when the vehicle was not in motion.
"It's the wheel bearings that you don't want to use moly grease on as they are high speed and supposidly the moly will cause excessive (uneven??) wear."
i would of thought that the CV joint turns at a pretty high speed too. i allways thought bearing grease is used because its opperates well under high pressures
The Birfield joint (not CV as you call it) actually moves very little in most driving and takes very little wear. When turning, it has more motion and the sharper the turn the more the motion. Obviously turning means you're moving slow, sharp turning moreso.
The primary wearing area would be the spindle bushing in everyday driving as it's a shaft turning on a "sorta touching, sorta not touching" surface. But even that is either unloaded (barely touching) or barely loaded. Moly has been known to cause small high speed bearings to be so slippery that they don't turn and develop a flat spot, so that's why it's a no no in needle bearings or wheel bearings in general. Dunno how much of that is no longer applicable as lubricants like grease continue to evolve into the fantastically effective substance they are today.
That Land Rover oil (I'm assuming you meant oil not grease) sounds interesting - not unlike the oil that's in a modern oil activated differential that reacts to temp of shearing instantly.
DougM
DougM
The primary wearing area would be the spindle bushing in everyday driving as it's a shaft turning on a "sorta touching, sorta not touching" surface. But even that is either unloaded (barely touching) or barely loaded. Moly has been known to cause small high speed bearings to be so slippery that they don't turn and develop a flat spot, so that's why it's a no no in needle bearings or wheel bearings in general. Dunno how much of that is no longer applicable as lubricants like grease continue to evolve into the fantastically effective substance they are today.
That Land Rover oil (I'm assuming you meant oil not grease) sounds interesting - not unlike the oil that's in a modern oil activated differential that reacts to temp of shearing instantly.
DougM
DougM
I have always felt that port was used for the factory fill of the knuckle cavity. The birfield joint itself would be pre-lubed when the knuckle was assembled and some robot probably filled the cavity with a high-pressure gun through that port, then another robot installed the plug. Just a guess though...
-B-
Actually, it's there for periodic adding of grease. The felt/rubber seal against the spherical surface on the knuckle is designed to weep a little grease to keep that surface rust free. Since it weeps a little (like an eyeball/eyelid does) you need to pump a little grease in the square plug's hole at every oil change or so.
Don't neglect your knuckles, or they'll neglect you...
As for assembly, these axles are most likely hand assembled on an assembly line and the guy tosses grease in just like a mechanic with an air driven grease gun would. They're piled up on pallets and later mated to vehicles. Using a robot on putting a knuckle together wouldn't be cost/time/investment effective. Does paint a pretty picture though. Can you imagine slapping 3 or 4 knuckles per hour together using brand new shiny parts and not a speck of dust anywhere in sight? More fun than a barrel of monkeys...
DougM
Don't neglect your knuckles, or they'll neglect you...
As for assembly, these axles are most likely hand assembled on an assembly line and the guy tosses grease in just like a mechanic with an air driven grease gun would. They're piled up on pallets and later mated to vehicles. Using a robot on putting a knuckle together wouldn't be cost/time/investment effective. Does paint a pretty picture though. Can you imagine slapping 3 or 4 knuckles per hour together using brand new shiny parts and not a speck of dust anywhere in sight? More fun than a barrel of monkeys...
DougM
Wrooong.
3/4 is enough, and you CAN overfill them. One of the first maintenance things I did when I bought this truck 6 years ago was lube the knuckles, using the "there's no such thing as too much" mentality. So I spared no expense and pumped those suckers full. Within an matter of weeks, I had birf soup spewing out of both knuckles.
Picture your knuckle housing like a blinder. Go fill a blinder up to the very top, put the lid on, turn it on and see what happens.
theres an addendum to the JDM for canada.
its 3/4 full molly, plus 6oz of labatts for a thinner. in a pinch you can use 1/2 jigger of crown royal, but youll have to repack every 3000 miles, as that stuff isnt as smooth as advertised, and it will burn the knuckle.
i heard a rumor that a glenfiddich shot is good for 18 years, but jury is still out.
its 3/4 full molly, plus 6oz of labatts for a thinner. in a pinch you can use 1/2 jigger of crown royal, but youll have to repack every 3000 miles, as that stuff isnt as smooth as advertised, and it will burn the knuckle.
i heard a rumor that a glenfiddich shot is good for 18 years, but jury is still out.
crushers
post ho
first, John is way out to lunch. you never add gear lube to grease, it turns grease to liquid. very stupid suggestion.
next, you never over fill the birf or the knuckle housing with grease. yes, grease will HELP keep water out so the proper amount is what you want.
if you are using the truck in EXTREME cold weather then use full syn grease.
you can not fill the birf by filling the knuckle, bad advice. now you can buy birfs that have a grease nipple for filling from the hub side. they are not cheap but it works.
finally, this is the interweb. not all you read or hear is going to be based on fact. use common sense and read the FSM if you are going to do your own work.
next, you never over fill the birf or the knuckle housing with grease. yes, grease will HELP keep water out so the proper amount is what you want.
if you are using the truck in EXTREME cold weather then use full syn grease.
you can not fill the birf by filling the knuckle, bad advice. now you can buy birfs that have a grease nipple for filling from the hub side. they are not cheap but it works.
finally, this is the interweb. not all you read or hear is going to be based on fact. use common sense and read the FSM if you are going to do your own work.
'Splain yourself here on being unable to 'fill the birf' by filling the knuckle (assume this is filling via the square plug). I disagree and held your position for 10 years before confirming it myself. I emphatically don't want to be confrontational here, so let's yak about it, eh?
The grease nipple on the hub side is an excellent idea, BTW. I considered having mine drilled and tapped during a rebuild (ironically the rebuild I did the colored grease thingy).
DougM
The grease nipple on the hub side is an excellent idea, BTW. I considered having mine drilled and tapped during a rebuild (ironically the rebuild I did the colored grease thingy).
DougM
crushers
post ho
okay, so the idea of filling the birf is to get grease into the balls.
to fill the balls you need pressure to push the grease into the vacant holes around the balls (you know, like hand pressure, not 100 ft lbs idea)
to get that kind of pressure you would have to fill the knuckle housing both around the outside of the axle cup and the inside with enough grease to PUSH the grease into the space.
to get that kind of pressure you would push past the dust seal at the back which will release the pressure needed.
get the idea?
to fill the balls you need pressure to push the grease into the vacant holes around the balls (you know, like hand pressure, not 100 ft lbs idea)
to get that kind of pressure you would have to fill the knuckle housing both around the outside of the axle cup and the inside with enough grease to PUSH the grease into the space.
to get that kind of pressure you would push past the dust seal at the back which will release the pressure needed.
get the idea?
I belive the op is strictly talking about the grease that fills the void in the housing. He says the cv joint is lubbed so why fill the housing. Obviously there needs to be grease in the housing as toyota has it there for a reason.
How much grease does it take to get the housing the reccomended 3/4 full?
How much grease does it take to get the housing the reccomended 3/4 full?
crushers
post ho
the grease in the housing achieves two things
it helps keep water out (but if you do a lot of deep water crossings it will still be contaminated)
it catches the small pieces of steel when a birf grenades to help prevent them from jambing into the small void beteen the outer axle housing and the knuckle housing which, when it does happens, can prevent the knuckle from being able to turn... ie you end up having to go straight instead of around that tree in front of you. but if you keep driving wiht a busted birf then these pieces will find their way into that void and then the fun begins.
it helps keep water out (but if you do a lot of deep water crossings it will still be contaminated)
it catches the small pieces of steel when a birf grenades to help prevent them from jambing into the small void beteen the outer axle housing and the knuckle housing which, when it does happens, can prevent the knuckle from being able to turn... ie you end up having to go straight instead of around that tree in front of you. but if you keep driving wiht a busted birf then these pieces will find their way into that void and then the fun begins.
Crush,
I see what you're saying regarding needing pressure to somehow get the grease to displace the air in the inner birf - where the balls and the star reside. Here's what happens when you pump grease into a knuckle low on grease. The grease goes into the knuckle in ribbons and spaghetti-like coils and simply falls to the bottom of the cavity - kinda like pumping grease into a room from a hole in the roof. Eventually, you fill to the point this stuff has piled up to the "roof" of the knuckle. When you drive, it gets heated and stirred around and the air works its way out of the churning grease as it heats and flows downward continuously. Park the truck and the room (previously empty) is 2/3 full now with an empty air space above and warm grease below. The ribbons of grease have all 'melted' and flowed into the bottom of the knuckle. If the birfield and star are below the "water line" of the grease, then they are completely submerged in fresh grease.
So, warm grease and gravity get the new grease down into the birfield joint itself. Somebody has posted the great diagram of the knuckle here that's in the FSM, which helps you understand it's one contiguous space in the knuckle from the birfield chamber all the way to the spindle tip - fed by the square plug. Frankly, I would not have believed this had I not done the experiment quite spontaneously before a repack, and as mentioned I believed fresh grease would not get to the birfields. I underestimated the amount of churning going on in the knuckle from the spinning bits. But I think if you visualize what's going on in there from my weak attempt above to explain it, it may be clear as mud (heh).
I think this highlights why it is so important to keep grease in there to the proper level (2/3 or more) because at the half way mark is the spindle bushing. A lot of folks here have trashed their spindle bushings and that gets very expensive.
DougM
I see what you're saying regarding needing pressure to somehow get the grease to displace the air in the inner birf - where the balls and the star reside. Here's what happens when you pump grease into a knuckle low on grease. The grease goes into the knuckle in ribbons and spaghetti-like coils and simply falls to the bottom of the cavity - kinda like pumping grease into a room from a hole in the roof. Eventually, you fill to the point this stuff has piled up to the "roof" of the knuckle. When you drive, it gets heated and stirred around and the air works its way out of the churning grease as it heats and flows downward continuously. Park the truck and the room (previously empty) is 2/3 full now with an empty air space above and warm grease below. The ribbons of grease have all 'melted' and flowed into the bottom of the knuckle. If the birfield and star are below the "water line" of the grease, then they are completely submerged in fresh grease.
So, warm grease and gravity get the new grease down into the birfield joint itself. Somebody has posted the great diagram of the knuckle here that's in the FSM, which helps you understand it's one contiguous space in the knuckle from the birfield chamber all the way to the spindle tip - fed by the square plug. Frankly, I would not have believed this had I not done the experiment quite spontaneously before a repack, and as mentioned I believed fresh grease would not get to the birfields. I underestimated the amount of churning going on in the knuckle from the spinning bits. But I think if you visualize what's going on in there from my weak attempt above to explain it, it may be clear as mud (heh).
I think this highlights why it is so important to keep grease in there to the proper level (2/3 or more) because at the half way mark is the spindle bushing. A lot of folks here have trashed their spindle bushings and that gets very expensive.
DougM
Doug,
How long before the repack did you put the new grease in the fill port, and how many miles would you guess you put on it in that time?
Hmm, that's a good question. I keep a log and may have noted it in there, but I recall posting it here if you're good at search. I think it was less than a couple weeks which would have been less than 500 miles. A usefully short period of time and miles.
DougM
DougM
crushers
post ho
WOW!!
that is quite the story.
i see in my minds eye what you are saying, the right side is saying "hey, he could be right", the left side is saying "bull tweedle".
since i have often wondered why they had the square plug in the housing i will have to accept your story as plausable
BUT
i don't think i will rely on that process independant of a proper grease job just in case the left side is correct.
that is quite the story.
i see in my minds eye what you are saying, the right side is saying "hey, he could be right", the left side is saying "bull tweedle".
since i have often wondered why they had the square plug in the housing i will have to accept your story as plausable
BUT
i don't think i will rely on that process independant of a proper grease job just in case the left side is correct.
scottm
SILVER Star
Has anyone found synthetic moly grease? That *might* not thicken as much in cold, synthetic engine oil seems to not thicken as much. I use Mr. Moly grease on the premise that it doesn't thin as readily at high temps, but I don't think it helps on the cold end.
As I understand it (hopefully Cary will fill in the blanks), oil is thickened to grease by adding lithium soaps. Then grease is "fortified" (like my brother's favorite wine) with moly (molybdenum disulfide {MoS2}) to decrease friction. If they start with synthetic oil, perhaps it wouldn't thicken?
I use moly on anything that doesn't have rolling contact surfaces, never on rolling surfaces. I don't think the balls in CV/birf joints actually roll against the spiders, the balls just maintain contact between the two spiders as they change angles. On rolling contacts, the grease isn't so much to help things slide, more to cushion and carry heat away. In a rolling bearing the rolling elements need enough friction to keep rolling, otherwise a roller can stall and skid and wear a flat spot. That leads quickly to failure. As my brother pointed out, that may not be important any more on modern, super accurate bearings, and very pure modern greases. Apparently lube manufacturers are putting moly in all kinds of lubes to juice their friction numbers cheaply. I think it was Cary who pointed out that Mobil 1 has moly in it.
As I understand it (hopefully Cary will fill in the blanks), oil is thickened to grease by adding lithium soaps. Then grease is "fortified" (like my brother's favorite wine) with moly (molybdenum disulfide {MoS2}) to decrease friction. If they start with synthetic oil, perhaps it wouldn't thicken?
I use moly on anything that doesn't have rolling contact surfaces, never on rolling surfaces. I don't think the balls in CV/birf joints actually roll against the spiders, the balls just maintain contact between the two spiders as they change angles. On rolling contacts, the grease isn't so much to help things slide, more to cushion and carry heat away. In a rolling bearing the rolling elements need enough friction to keep rolling, otherwise a roller can stall and skid and wear a flat spot. That leads quickly to failure. As my brother pointed out, that may not be important any more on modern, super accurate bearings, and very pure modern greases. Apparently lube manufacturers are putting moly in all kinds of lubes to juice their friction numbers cheaply. I think it was Cary who pointed out that Mobil 1 has moly in it.
