Johnny Joint grease—an experiment

I’ve decided to try an experiment of my own . I’ve ordered a tube of Molykote 1502FM . I plan on using it in the used Johnny Joints I just purchased . I’ll run them for a full season and then disassemble and inspect them them . Unless I have an issue with self destruction, or at least an unusual amount of noise , I’ll just leave them be until this Fall .
https://www.dupont.com/products/molykote-g-1502-fm-synthetic-bearing-and-gear-grease.html
 
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ok, so here goes.

I collected 2 samples of clay-rich soil from my property in Oklahoma.

We have two flavors of clay...the red stuff, and the white stuff, so I got one of each. I can't tell you if these specific samples were "native" to my property or whether they rode in with some fill dirt because there are 4 houses in different phases of construction on my street and mine is in the middle of them.

I cut the bottoms off of some solo cups to create some petri dishes, placed a generous dab of Redline CV2 grease w/ moly into two of them and a dab of Energy Suspension "Formula 5 Prelube" into the other. I then filled the dish with amounts of dry red and white clay as to completely surround the grease to a consistent depth with a little dust scattered up on the side.

The fifth dish without any dirt is the control, because science.

View attachment 308480

I'll take photos every 24 hours until either results appear obvious or it becomes apparent that they're going to happen on a slower scale than justifies daily checks.

My first thought was that you need to take you cat to the vet.
 
I didn't take a 24 hour photo because I couldn't see a difference, but here's the 48 hour photo and I can see things happening with a flashed photo that aren't obvious to the naked eye.

Namely, the darkening of the clay in the immediate vicinity of the grease. It's happening with both greases, but it does seem to be more pronounced, or progressing farther into the clay, with the CV2.


PXL_20220211_210450296.jpg


Obviously our concern is not necessarily what happens to the dirt, but the grease that's left behind, so it'll be interesting to see if I can observe anything there as time goes on. It occurred to me that I maybe should have used smaller amounts of grease since any of these dabs is multiples more volume than would be present in a JJ...but it's difficult to only use that amount and have enough to observe.
 
I didn't take a 24 hour photo because I couldn't see a difference, but here's the 48 hour photo and I can see things happening with a flashed photo that aren't obvious to the naked eye.

Namely, the darkening of the clay in the immediate vicinity of the grease. It's happening with both greases, but it does seem to be more pronounced, or progressing farther into the clay, with the CV2.


View attachment 309034

Obviously our concern is not necessarily what happens to the dirt, but the grease that's left behind, so it'll be interesting to see if I can observe anything there as time goes on. It occurred to me that I maybe should have used smaller amounts of grease since any of these dabs is multiples more volume than would be present in a JJ...but it's difficult to only use that amount and have enough to observe.
Those dark areas are the oils being leeched out of the grease, I'd bet. Be interesting to see this progress.
 
Here's the latest photo. The oily spot continues to grow, and is still more advanced with the CV2 than with the F5P.


PXL_20220222_214216337.jpg



I think my grease:clay ratio is too high to tell me anything meaningful about the grease that's left behind, so I may let this go for a couple more weeks and then start with a new set with smaller dabs of grease and more dirt. I'll probably just go for the white stuff since it seems to have more of the absorbent properties we're concerned about, and the dirt work at our house is at a stage where I have all of it that I could ever need.

PXL_20220220_165302454.jpg
 
Here's the latest photo. The oily spot continues to grow, and is still more advanced with the CV2 than with the F5P.


View attachment 311594


I think my grease:clay ratio is too high to tell me anything meaningful about the grease that's left behind, so I may let this go for a couple more weeks and then start with a new set with smaller dabs of grease and more dirt. I'll probably just go for the white stuff since it seems to have more of the absorbent properties we're concerned about, and the dirt work at our house is at a stage where I have all of it that I could ever need.

View attachment 311598

Nice work! I think it's reasonable to infer that more oil absorbed by the clay means less oil left behind.

While it would be ideal to directly measure the grease left behind, do you have a good way to do that? Could you tell if one lost 10% of it's oil and the other lost 30%? Or would you have to wait until the oil was all gone and it no longer felt like grease?
 
Nice work! I think it's reasonable to infer that more oil absorbed by the clay means less oil left behind.

While it would be ideal to directly measure the grease left behind, do you have a good way to do that? Could you tell if one lost 10% of it's oil and the other lost 30%? Or would you have to wait until the oil was all gone and it no longer felt like grease?

I think you're probably right, I just wish it was more definitive.

Waiting until all the oil is gone is probably the only definitive result I have at my disposal right now. Thinking of another way, like comparing viscosity, would be better I think. Just gotta figure out a good way to do it since neither of them will flow through an orifice under the force of gravity even when brand new.
 
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I rebuilt a couple of my lower control arms today. These were greased with energy suspension formula 5 about a year ago. I went wheeling a couple times with them and drove them a couple times this winter (salt).

Pretty disappointed to see the amount of corrosion present in the joint.
IMG_20220423_143916042.jpg


The joints were still moving though and not squeaking. They were dry though... The grease that was present was still the same consistency of the stuff when fresh, so there is that.

Based on the corrosion, I decided to hit the center balls with a zinc chromate solution. It's pretty easy to do at home, lots of DIY articles and videos around.

Here is a "raw" zinc plating, and one that I've polished with 000 steel wool.

IMG_20220423_174357641_HDR.jpg


I do two zinc plating baths, then dip the parts in a yellow chromate bath. It's not as good as a commercial bath, but it is better than raw steel. The yellow is tough to photograph... These look pretty close to grade 8 bolts, but lighter.

IMG_20220423_180508396_HDR.jpg


And, one final experiment...I assembled a joint and tried to grease it through the housing grease zerk. I got 4 pumps of grease in before the grease started squeezing out of areas.

Then I disassembled the joint again to see where the grease went.

IMG_20220423_191847377_HDR.jpg


It basically filled the outer "ring" area and put a witness on the ball, but no grease made it between the ball and the race... The joint was dry. I also got grease through the hole in the ball and on the bolt. So... That won't work.
 
I rebuilt a couple of my lower control arms today. These were greased with energy suspension formula 5 about a year ago. I went wheeling a couple times with them and drove them a couple times this winter (salt).

Pretty disappointed to see the amount of corrosion present in the joint.View attachment 325014

The joints were still moving though and not squeaking. They were dry though... The grease that was present was still the same consistency of the stuff when fresh, so there is that.

Based on the corrosion, I decided to hit the center balls with a zinc chromate solution. It's pretty easy to do at home, lots of DIY articles and videos around.

Here is a "raw" zinc plating, and one that I've polished with 000 steel wool.

View attachment 325017

I do two zinc plating baths, then dip the parts in a yellow chromate bath. It's not as good as a commercial bath, but it is better than raw steel. The yellow is tough to photograph... These look pretty close to grade 8 bolts, but lighter.

View attachment 325018

And, one final experiment...I assembled a joint and tried to grease it through the housing grease zerk. I got 4 pumps of grease in before the grease started squeezing out of areas.

Then I disassembled the joint again to see where the grease went.

View attachment 325023

It basically filled the outer "ring" area and put a witness on the ball, but no grease made it between the ball and the race... The joint was dry. I also got grease through the hole in the ball and on the bolt. So... That won't work.

Very interesting. My experiment kinda lost my attention but I haven't thrown it out. The "wet" area of the clay is about 5x as big with the cv2 as it is with the F5 prelube, but I used too much grease-to-clay to be able to see any change in the grease itself.

No salt here so it'll be interesting to see if mine have the corrosion like yours. If they do I suppose I might be learning to do a zinc chromate coating.

On the subject of coatings though... What about Teflon? Are there hobbyist options for that, and would it stick to the steel against the polyurethane under the preload pressure on a JJ? I just know my eggs slide off it like a banana in Mario kart.
 
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Very interesting. My experiment kinda lost my attention but I haven't thrown it out. The "wet" area of the clay is about 5x as big with the cv2 as it is with the F5 prelube, but I used too much grease-to-clay to be able to see any change in the grease itself.

No salt here so it'll be interesting to see if mine have the corrosion like yours. If they do I suppose I might be learning to do a zinc chromate coating.

On the subject of coatings though... What about Teflon? Are there hobbyist options for that, and would it stick to the steel against the polyurethane under the preload pressure on a JJ? I just know my eggs slide off it like a banana in Mario kart.
No idea on the teflon.
 
No idea on the teflon.
We need to find out what that blue coating is on the drive shaft slip splines. That's some pretty durable stuff.

I think someone from this thread called me yesterday.

Hey, what's the best grease for Johnny Joints?

I use Redline CV-2 with good success.

Is it better than what Rock Jock uses?

What question did you ask me?

I asked what the best grease is?

Yes you did and I answered that question.

What do they put in it that makes it better?

No idea, I don't make the grease.

Is it better than what RJ uses?

I answered that question already.

But what makes it better?

I answered that question as well.

Yes, but I'm trying to find out what the best grease to use is.

click
 
We need to find out what that blue coating is on the drive shaft slip splines. That's some pretty durable stuff.

Spicer calls it "Glidecote" in their literature. I remember reading that it is some version of nylon/Teflon. @Shawn at Tom Wood's may know perhaps?

We have a guy at work who deals with marketing/sales teams. He often describes phone calls like these .. same question asked 20 different ways and sometimes repeated in-between other questions.
 
We need to find out what that blue coating is on the drive shaft slip splines. That's some pretty durable stuff.

I think someone from this thread called me yesterday.

Hey, what's the best grease for Johnny Joints?

I use Redline CV-2 with good success.

Is it better than what Rock Jock uses?

What question did you ask me?

I asked what the best grease is?

Yes you did and I answered that question.

What do they put in it that makes it better?

No idea, I don't make the grease.

Is it better than what RJ uses?

I answered that question already.

But what makes it better?

I answered that question as well.

Yes, but I'm trying to find out what the best grease to use is.

click
Spicer calls it "Glidecote" in their literature. I remember reading that it is some version of nylon/Teflon. @Shawn at Tom Wood's may know perhaps?

We have a guy at work who deals with marketing/sales teams. He often describes phone calls like these .. same question asked 20 different ways and sometimes repeated in-between other questions.


I have an intermediate shaft in my motorhome steering system that has a slip joint like a driveshaft. It also had that blue Teflon/plastic coating on it. In the last 45 years my motorhome has been in existence, that coating broke down and due to the steering shaft orientation and neglect, water was allowed into the joint and under the coating. I had to strip it to restore the shaft (not really something you can go pick up at AutoZone)

Once I got that apart, I called around, including Tom Woods, to see if anyone could recoat it. I was told no, repeatedly.

I ended up having the shaft hardchromed and OD ground to regain the thickness necessary to replace the coating thickness (about 0.010"). It worked, but was a pain.


Long story, but yes, that blue stuff would be great, but it's probably some special overmolded product that is very capital intensive to apply...so Dana/Spicer, American Axle, Sterling, etc can afford to do it, but your average driveshaft shop wouldn't make that investment.
 
We need to find out what that blue coating is on the drive shaft slip splines. That's some pretty durable stuff.

I think someone from this thread called me yesterday.

Hey, what's the best grease for Johnny Joints?

I use Redline CV-2 with good success.

Is it better than what Rock Jock uses?

What question did you ask me?

I asked what the best grease is?

Yes you did and I answered that question.

What do they put in it that makes it better?

No idea, I don't make the grease.

Is it better than what RJ uses?

I answered that question already.

But what makes it better?

I answered that question as well.

Yes, but I'm trying to find out what the best grease to use is.

click
It is referred to as Glidecoat and is an injection overmold. Not sure if there is any PTFE in it but it is pretty slick. It has a serious flaw that just like bedliner if is get a nick and let’s contaminants under it you have a guaranteed failure.

And I get those exact same questions when it comes to what oil for an 8274.
 
I rebuilt a couple of my lower control arms today. These were greased with energy suspension formula 5 about a year ago. I went wheeling a couple times with them and drove them a couple times this winter (salt).

Pretty disappointed to see the amount of corrosion present in the joint.View attachment 325014
I would have never expected this. That looks like it has been neglected for years! :(
 
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It is referred to as Glidecoat and is an injection overmold. Not sure if there is any PTFE in it but it is pretty slick. It has a serious flaw that just like bedliner if is get a nick and let’s contaminants under it you have a guaranteed failure.

And I get those exact same questions when it comes to what oil for an 8274.

Just like teflon fry pans. Great when new but crap in the long run. I'll stick with cast iron that re-seasons itself every time it's used. It'd be funny to see how a seasoned JJ ball performs. Just don't let the wife catch you!

If you want a teflon rod end they make those, but they aren't rebuildable.
 
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I was pretty surprised to see it as well.
You likely know a guy within arm's reach who could whip you out a set of 8 lower balls in 400C in not much time. That is certainly an experiment I would try if I lived where my parts rusted like that. I'd also try a bead blasted finish on half of them versus smooth to see if that holds grease better.
 
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