Builds g-man's land cruiser story

[NeverGiveUpYota]

how critical is the bearing support tool ?
View attachment 1983474

I’m not following your question? You mean how to press it in to the top and bottom of the knuckle? I just used a brass rod held flat and tapped it as I spun it in a circle.
Scratch all that.
IF you find the tool, you’ll have all that you need to do that step.

 

[g-man]

I’m not following your question? You mean how to press it in to the top and bottom of the knuckle? I just used a brass rod held flat and tapped it as I spun it in a circle.
Scratch all that.
IF you find the tool, you’ll have all that you need to do that step.

FSM shows two parts; first is centering the knuckle which helps you find the shim thicknesses.

Then the other sst that supports the bearings from the inside while you tap the bearing caps in place (edit) this is done when your ready to permanently install the knuckle and after you found and installed the right shims.

my question is ...how necessary is the support tool? I don't see much talk about using it. I'm guessing the bearings and race will be just fine as long as the bearing cap and hole in the center of the bearing are greased and everything goes in straight w/out excessive pressure. Maybe put the bearing caps in the freezer first?

 

[NeverGiveUpYota]

@60Works able to add input here?

 

[g-man]

Napa has a big tub of wheel bearing and chassis grease. It’s what I used per what @mwebfj60 uses and I fully respect his choices; he ain’t no dummy. And I was gifted the Timkin tub so I figured I’d use it for the bearings at minimum.

View attachment 1983503

I have that same mp wheel bearing grease (the bottom tub) and use it for wheel bearings and the hub. But the FSM says to use Molybdenum disulphide lithium based grease for the knuckle and the birf joint. I'll need to buy a tub of moly for the knuckle. Just hoping for something that doesn't separate. That way I know if I see drips that I have to address the seal again.

 

[60Works]

@60Works able to add input here?

Not quite sure where to start. g-man, you've got a lot of issues all happening at once.

All grease will separate, even the good stuff. A grease's base (clay or lithium soap) does not lubricate. It merely provides a medium to hold the lubricant in place. Otherwise it would be merely a viscus oil draining out and needing to be constantly replenished by a pumping system. There are several good threads speculating about the FSM calls out for different greases for the chassis, birfs, and bearings.

Moly greases are lithium soap based and are spec'd for high loading applications. 5% moly is widely available. 10% moly is harder to find. Look for heavy equipment grease; the stickier and more impossible to clean from your clothes the better.

Wheel bearing greases are clay based are are spec'd for high temperature applications. Disk brakes generate high heat. On aircraft the brakes get hot enough to ignite some greases and most FSM's caution tech's about using too much of even a high flashpoint grease.

DO NOT MIX GREASE TYPES! They react to each other and degrade the lubricating ability of both.

All that said, its a pain to stock multiple greases and worry about ruining a u-joint because your out of moly. I've tried both types over the years and have settled with using only moly on everything. Working in aviation we often have 'expired' grease that needs to be disposed of. Hard to imagine that 100 million year old dinosaurs expire (some of the additives do degrade). I've used a lot of 3 year old super expensive, synthetic greases in my cruisers. Cruisers don't seem to care much one way or the other so long as they always have enough.

My favorite is Aeroshell 64, MIL-G-21164D. Designed for aircraft operating between -80°F and 130°F, it stays soft even in NH winters. It does separate but not as badly as the clay bases wheel bearing grease Mobile 28. I would recommend using a 5-10% moly synthetic grease. Beyond that, I don't think it matters very much which brand. Its probably all sourced from the same refinery, who just dump it into different label buckets, send it to multiple vendors with varying levels of over-hyped marketing trying to convince buyers that their brand is somehow better because their label is red instead of green. (I'm pretty cynical about marketing.)

 

[jcj_78FJ40]

Search "Otramm knuckle rebuild" video with lots of good info.

 

[60Works]

For your birfield:

You only need to use the tool if you don't like rebuilding your front axle every few years.

Meaning, you're having to do a nasty job again because you probably missied something important last time. It's how we all learn. Don't sweat it, but be good to yourself and use the FSM this time. The trunion bearing might have failed because you bashed the bottom cap on the rocks while wheeling. But most likely the birf wasn't centered properly and it really didn't like it. Sometimes the axle housing is bent at the narrow neck next just before the ball.

The bushings come camferred to accomodate the milling radius on the birf shaft so that much probably wasn't cut up by the birf. New spindle bushings must be honed to the correct dimension so they don't grab the axle and seize. I don't know the dimension and it's not in the FSM. When I tried to replace the bushings I ruined 3 of them, decided I was wasting more of my time than the cost of new spindles with new bushings. I called Kurt and solved the issue.

The oil seal does not provide any support or thrust limits. All it does is conform to the axle the best it can. If the axle is not in the absolute, exact concentric center of the seal, it won't seal for very long. The axle has a smooth surface for the seal allowing 5-7 mm of lateral travel. I haven't had any better luck with Marlin's seals than with Toyota's.

The axle is supported in 3 places; the differential, the spindle bushing, and minimally at the locking hub. It is limited in lateral motion inboard by the snap ring in the hub and in outboard travel by the thrust surface of the spindle bushing. It normally has in and out play of 3-4 mm. Within this normal lateral play, the birfield will find it's own center; aligning its universal hinge point with the center of the trunion bearing rotating axis and the center of the spindle bushing. If the birfield can't find this intersection of 3 axis' because it's trapped, massive forces build exponentially with degree of steering travel until something grenades.

 

[g-man]

@60Works, My axle was leaky before CMCC but not dripping on the wheel, just wet at the bearing cap nuts/studs. This is just a good example of how important it is to address a leaky inner seal. Obviously I had other problems. After reading your comment on the bushing I wish I had left mine alone. But it's already been knocked out of the spindle (and destroyed). Kurt @cruiseroutfit recommended replacing the bushing. Waiting for another. Figured I'd take it to a shop to press in and take them the axle so they could hone it to fit. Also I put the marlin crawler seal in...so I have to get another, destroy/remove that one so I can use the centering tool.

The end of this OTRAMM video doesn't make me feel very confident. He uses the tool to calculate the correct shim thicknesses then decides to use the existing shims even though they are not the numbers he calculated using the tool. So it seems he trusts the original shims. But in my case with things going south I don't trust my shims to be in the right spot.

 

[Nostradamus]

Not quite sure where to start. g-man, you've got a lot of issues all happening at once.

All grease will separate, even the good stuff. A grease's base (clay or lithium soap) does not lubricate. It merely provides a medium to hold the lubricant in place. Otherwise it would be merely a viscus oil draining out and needing to be constantly replenished by a pumping system. There are several good threads speculating about the FSM calls out for different greases for the chassis, birfs, and bearings.

Moly greases are lithium soap based and are spec'd for high loading applications. 5% moly is widely available. 10% moly is harder to find. Look for heavy equipment grease; the stickier and more impossible to clean from your clothes the better.

Wheel bearing greases are clay based are are spec'd for high temperature applications. Disk brakes generate high heat. On aircraft the brakes get hot enough to ignite some greases and most FSM's caution tech's about using too much of even a high flashpoint grease.

DO NOT MIX GREASE TYPES! They react to each other and degrade the lubricating ability of both.

All that said, its a pain to stock multiple greases and worry about ruining a u-joint because your out of moly. I've tried both types over the years and have settled with using only moly on everything. Working in aviation we often have 'expired' grease that needs to be disposed of. Hard to imagine that 100 million year old dinosaurs expire (some of the additives do degrade). I've used a lot of 3 year old super expensive, synthetic greases in my cruisers. Cruisers don't seem to care much one way or the other so long as they always have enough.

My favorite is Aeroshell 64, MIL-G-21164D. Designed for aircraft operating between -80°F and 130°F, it stays soft even in NH winters. It does separate but not as badly as the clay bases wheel bearing grease Mobile 28. I would recommend using a 5-10% moly synthetic grease. Beyond that, I don't think it matters very much which brand. Its probably all sourced from the same refinery, who just dump it into different label buckets, send it to multiple vendors with varying levels of over-hyped marketing trying to convince buyers that their brand is somehow better because their label is red instead of green. (I'm pretty cynical about marketing.)

Wow. I just learned 4x more about grease than I knew before reading this post. Thank you.

 

[60Works]

Every untouched axle I've disassembled has had the same quantity and thickness of shims under each cap (which I embarrassingly can't remember right now.). On axles which had been previously disassembled, the shims have varied. Do you recall what was under each when you did yours last? Were you the first person to disassemble the axle? Did you make sure the shims were replaced exactly as you found them? You now have reason to believe the shims to be incorrect so using the tool to verify would be a very good idea.

If your axle was clean and untouched, your shims carefully tracked and consisting of the 'standard' assortment - then reassembling without the tool would be a reasonable choice.

 

[g-man]

Every untouched axle I've disassembled has had the same quantity and thickness of shims under each cap (which I embarrassingly can't remember right now.). On axles which had been previously disassembled, the shims have varied. Do you recall what was under each when you did yours last? Were you the first person to disassemble the axle? Did you make sure the shims were replaced exactly as you found them? You now have reason to believe the shims to be incorrect so using the tool to verify would be a very good idea.

If your axle was clean and untouched, your shims carefully tracked and consisting of the 'standard' assortment - then reassembling without the tool would be a reasonable choice.

My thoughts exactly.

 

[g-man]

FWIW i have one thick shim on the bottom bearing cap and one thick and one thin one on the top. Not sure If i moved these when I did the knuckles last. Not sure if someone may have been in there before me. I bought it when it was 20 years old and had 211k miles on it. No telling. But at this point doing the knuckle centering makes sense. Can't get much worse.

 

[g-man]

I took a dremel and knocked off some of the pointed edges inside the axle housing and under where the upper trunnion races sit. I noticed that the birf joint wore the metal down where the upper race sits. The thickness is roughly 1/2 what it was. I am debating on filling this gap up with a welder and then grinding it down with the dremel. Here is the image. You can see the correct thickness on the inside part (in red) and the outer part (edit: the part that is worn thin) as seen in mirror (in green) The purple line shows where the birf joint rubbed away the metal.

 

[g-man]

spindle bearing came in today. Fit nicely on the axle. Then I pressed it into the spindle and of course it's too tight to go on the axle now so it needs to be honed. So I'm looking for clearance spec. I suppose I can take the good spindle/bushing off the other side and carry it all to a shop.

 

[g-man]

local API has a king pin hone but its broken. Just put some 320 grit on a socket. Put some tape on the socket first to get it a bit snug. Then sprayed oil and reamed the bushing by hand. Did this til it went about 1/2 way on the axle. Then just pushed and turned the spindle until it seated. Amazingly once it was seated it was loose and spinning freely. Came off by hand too. Hopefully this will work.

 

[g-man]

Circled in red is where I took the pointed areas down. Circled in green is the low spot I am considering filling.

 

[g-man]

@60Works What if anything did you use to lube between the birf and the spindle bushing. The FSM doesn't mention a lube here. But the bushing has some grooves in it....maybe just for heat expansion? Feel like it needs some oil or something.

Also I've some gold looking flakes in my birf soup in the birf joint. I was thinking about repacking it. I really don't want to disassemble cause I've read that it's easy to break a snap ring. And I've already ordered a ton of parts and tools. Should I spray it out with some brake clean and just repack it like a wheel bearing w/out taking it apart. Or should I just repack it w/out spraying it out.

It flexes good so I think everything in there is in good shape.

 

[Jaric00n]

if you have flakes in there it would be good to inspect

 

[g-man]

if you have flakes in there it would be good to inspect

Damn you. I've read up on servicing this. Doesn't look to bad. Just don't want to find any other probs ya know.

 

[Jaric00n]

push fresh grease into it and cross fingers

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