So far not impressed with Johnny Joints

someguysjeep said:
why would the zerk on the joint not grease the bushings, it's gonna fill the entire casing.
either way would /should work. zerk on the bolt needs matched to a cross drilled ball. or an external fitting directly into the joint casing.

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As I understand it, there are two pieces to this. First, is the assumption that grease is able to fill the entire casing via the housing zerk or the drilled ball. Second, if one were able to fill the entire casing via these ports, you risk blowing the poly race out of the side of the housing due to the pressures involved in filling the entire casing.

I'm pretty sure Blaine described this earlier in this thread.
 
jjvw said:
As I understand it, there are two pieces to this. First, is the assumption that grease is able to fill the entire casing via the housing zerk or the drilled ball. Second, if one were able to fill the entire casing via these ports, you risk blowing the poly race out of the side of the housing due to the pressures involved in filling the entire casing.

I'm pretty sure Blaine described this earlier in this thread.
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A zerk on one side of the forging and "vent" on the other side of the forging would probably work better...but once it's filled with grease during assembly, neither is necessary after that point.
 
jjvw said:
As I understand it, there are two pieces to this. First, is the assumption that grease is able to fill the entire casing via the housing zerk or the drilled ball. Second, if one were able to fill the entire casing via these ports, you risk blowing the poly race out of the side of the housing due to the pressures involved in filling the entire casing.
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you blow that snap ring out and you got 1 hell of a grease gun.

but as mentioned, the service is yearly if your anal about it, bi annual if your indifferent, and never if your lazy.
they thing only requires a thin coating. and i'd imagine the tolerance the construction holds would allow barely a single push of the handle.

to go 1 step further manual application would be best then the moving parts are actually seen and inspected.
 
PatMc said:
A zerk on one side of the forging and "vent" on the other side of the forging would probably work better...but once it's filled with grease during assembly, neither is necessary after that point.
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Run that idea by Currie. ;)
 
i can stand on my grease gun handle and my currectlynk steering sys won't take a drop if the grease channel is not lined up, 6000# or not.
 
ok dig this, exterior zerk flows to cross drilled ball into vented bolt.
or backwards, vented casing cross drilled ball and zerk on bolt.

open sys complete pass through, cap both ends after service.

but were always coming back to tolerance, it's so tight your never gonna get more than a skim coat in there.
 
PatMc said:
A smooth ball running between poly bearings will last considerably longer. If the ball had a slot in it, and that slot were to come in contact with the poly bearings, it would effectively act like a cheese grater. That's likely why they don't do it anymore.
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The slot is inside the bolt bore and lines up with the hole for the grease to get into the race.
 
PatMc said:
Well, The poly bushings don't touch each other...there is a small unsupported area there. If that area remains full of grease, that's all the lube it will ever need...Once it's greased properly, you shouldn't have to touch it again. The reason that polymers are used rather than sintered metal is that they don't require much lube. The lube exists for the primary purpose of filling an area so that there is no room for contaminants to enter.

Just like aftermarket non-greaseable ball joints....A lot of folks say they're crap because they don't last long (not talking specifically about Jeeps here)...but I feel a lot of that is due to the fact that most don't come with nearly enough grease in them...the boots are dry if you pull them off. I fill the boots with grease before installation so the excess spooges out, thus creating a "boundary seal", and making the boot considerably more useful...then they don't wear out because there is no room for water or other schmoo to enter the part.
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The poly bushings in the JJ are castellated with half inner and half outer so that the two ends interface and effectively overlap. Makes it a real pain in the ass to put them together since you have to line up the castellated sections since they are both the same part.
 
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jjvw said:
Regarding the slot or hole in the ball, if the zerk in the outer housing isn't sufficient to get grease throughout the bearing surfaces, why would the ability to get sufficient grease through the grease bolt and then through the drilled ball be any different?
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The grease fitting in the body almost always injects grease between the race and the barrel. At least with the bolts there is a slightly better chance of getting it between the ball and race where it belongs.
 
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someguysjeep said:
why would the zerk on the joint not grease the bushings, it's gonna fill the entire casing.
either way would /should work. zerk on the bolt needs matched to a cross drilled ball. or an external fitting directly into the joint casing.

but if zerk shear is an issue i'd remove and cap them so no contaminants could enter the joint, no matter what type is used.
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The body fitting injects grease between the body and the race effectively sealing off the area around the ball. When that happens and you keep trying to grease it, the high pressure will extrude the race out through the washer. 10,000 psi does some bad things.
 
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mrblaine said:
The body fitting injects grease between the body and the race effectively sealing off the area around the ball. When that happens and you keep trying to grease it, the high pressure will extrude the race out through the washer. 10,000 psi does some bad things.
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so your saying the castled bearings are interlocked and leave no room for pass through? does the castle-ation not line up and provide an access port from multiple directions once interlocked.

currie bushing.PNG
 
my big snap ring pliers are at work, dammit. now i have to see this construction for myself.

and my new joints have no external zerk , so i fully expect when i open 1 tomorrow. it better have a cross drilled ball. if not this unit could only be considered "sealed for life". or manually serviced through disassembly only.
 
someguysjeep said:
my new joints have no external zerk , so i fully expect when i open 1 tomorrow. it better have a cross drilled ball. if not this unit could only be considered "sealed for life". or manually serviced through disassembly only.
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Who made your arms? I'm trying to figure out why there are two versions of the Johnny Joint.
 
someguysjeep said:
so your saying the castled bearings are interlocked and leave no room for pass through? does the castle-ation not line up and provide an access port from multiple directions once interlocked.

View attachment 129410
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Technically, the ports are supposed to allow grease to reach the ball. I've not found that to be the case.
 
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Mike the Silver TJ said:
Who made your arms? I'm trying to figure out why there are two versions of the Johnny Joint.
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There is more than two. There are several versions depending on application. The narrow versions are typically for rear trackbars. Next width would be for upper TJ control arms, then the standard width lower. Then that width has two shank sizes, 1" and 1 1/4". They also make or made a 3" width builder joint, several different barrels without shanks, and then a entire line of billet series and I believe those run a single piece race that the ball gets pressed into and then that gets pressed into the housing.
 
mrblaine said:
There is more than two. There are several versions depending on application. The narrow versions are typically for rear trackbars. Next width would be for upper TJ control arms, then the standard width lower. Then that width has two shank sizes, 1" and 1 1/4". They also make or made a 3" width builder joint, several different barrels without shanks, and then a entire line of billet series and I believe those run a single piece race that the ball gets pressed into and then that gets pressed into the housing.
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I think it should be obvious I was referring to two different methods of greasing the joint, sorry if that was not clear.

The email I received from Savvy indicates two different versions are used in the TJ application. If you purchase Savvy arms you get a zerk in the housing. If you purchase Currie arms you get hollow bolts with a grease zerk and a slot in the ball. Which of these is prefered over the long run?

All of my joints for upper control arms are the same on the set I just purchased.
 
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