silcone vs teflon vs moly vs ?

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skk

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If you were going to use a grease to lube a suspension link that had a steel spherical sleeve encased in polyurethane what would you use?

It looks like this:
currierodend.jpg
 
Some petroleum products (grease) might either soften or harden polyurethane. Both Silicone and Teflon would need some carrier like oil or grease. I would use what the manufacturer of the polyurethane and see what they recommend.
 
I've used general purpose moly grease in suspension components with polyurethane, such as leaf spring bushings. I haven't seen the grease do anything mean to the urethane. However, that doesn't mean it's the "right" stuff to use.
 
I starting coming at this decision process with the assumption that using non-synthetic, petroleum based grease was harmful to polyurethane bushings. The more I read the more it seemed this to be a myth, would that still be the consensus?

Also, it seems that the urethane manufacturers like to recommend greases with silicone or teflon in them.

Here, this suspension joint is a little different from any regular urethane control arm or leaf spring bushing in that the inner sleeve moves and rotates on the inside diameter of the urethane bushings that holds it. So that is where I started to believe that the moly additive would be needed. I don't know what kind of pressure the joint is subjected to, but during it's pivot movements and shockloads, it does face some tough conditions, which is magnified since this is an offroad use application.

The maker of the joint (Currie Enterprises) suggested any grease with moly in it, although they were not very helpful in further discussing grease options for their joint. I do not know who the urethane manufacturer is that makes the bushing halves for the joint.

Any other feedback is helpful, thanks.
 
My Roto Joints (UMI) are similar to those (although they may use Delrin instead of poly bushings).

They seem to swear by the Super Lube grease for use in their products.
 
Originally Posted By: skk
I starting coming at this decision process with the assumption that using non-synthetic, petroleum based grease was harmful to polyurethane bushings. The more I read the more it seemed this to be a myth, would that still be the consensus?

Also, it seems that the urethane manufacturers like to recommend greases with silicone or teflon in them.


The maker of the joint (Currie Enterprises) suggested any grease with moly in it, although they were not very helpful in further discussing grease options for their joint. I do not know who the urethane manufacturer is that makes the bushing halves for the joint.

Any other feedback is helpful, thanks.


Seems like there should be an easy answer for this, the key word being "seems". I don't know about the petroleum/urethane compatibility.

Here's Super Lube's compatibility chart: http://www.super-lube.com/files/pdfs/Super_Lube_Compatability_Chart.pdf

You might be able to get the Dow Molykote folks to give you an answer. Their many products seem to be silicone based with moly additive.

Let us know what you learn. Good luck.
 
Well, I came across some instructions for assembly/disassembly of these Currie Johnny Joints and the instructions state they use a grease with moly in it, they actually mentioned the brand Chevron. I do not believe that Chevron has a synthetic grease with moly, so that would mean they were using Delo HD EP moly 3%, Delo HD EP moly 5% or their just their EP moly grease.

So some of the questions still remain; teflon/ptfe vs moly?
-and-
synthetic or petroleum base?

Synthetic SuperLube uses ptfe and shows compatibility with polyurethane.

I also had Synthetic TriFlow grease with Telfon recommended to me by somebody who is into this stuff. That company only say "is compatible with most rubbers and plastics" which probably means polyurethane too.

On a side note I did come across some lengthy compatibility charts such as this http://www.rubber-group.com/Library/compatability.PDF

A couple things:
Polyurethane acceptable and recommended with:
liquid petroleum gas (lpg), Mobil oil SAE 20, Petroleum oil (crude), Red Line 100 Oil, Silicone Greases, Sunoco All-purpose grease

Polyurethane "minor to moderate effect" with:
lubricating oils (petroleum base), lubricating oils (SAE 10, 20, 30, 40, 50), Mobil Delvac 1100, 1110, 1120, 1130, Natural Gas, Petroleum oil below 250F, Soybean Oil,

Polyurethane "moderate to severe" with:
Propane

Polyurethane "unsatisfactory" with"
Petroleum oil (above 250f)

I am more confused after reading through that, alot seems to contradict if one was trying to see if petroleum or synthetic oils/greases are ok or harmful to polyurethane.

If I thought I was over thinking this then I'd just go down the street to my friendly Chevron distributor and get one of their non-synthetic greases with moly.

If I was thinking that maybe I should use synthetic, or something more specialized with silicone or ptfe, or teflon (or synthetic moly) then I'd be considered SuperLube, Amsoil...others.

Not really sure on anything yet.
 
Amsoil Synthetic Polymeric Off-Road grease (5% moly, ) $9.95 for 15oz seems like a bargain (on Amsoil.com)

SuperLube (ptfe) $12.77 14oz tube on Amazon.
TriFlow (teflon) $20.75 14oz tube at Grainger.

Not sure about the HD Chevron Delo 3 or 5% moly non-syn pricing right now, but it will likely be under $8 a tube I am guessing.

Then how about these extra super fancy silicone type greases the urethane bushing companies offer?

Daystar (teflon) 3oz tube $16.95 (Summit)
Prothane (teflon) 14oz tube $25.95 (Summit)
Energy Suspension (teflon) 8oz $10.99
 
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Conversations with Amsoil and Schaeffers this morning.

Amsoil rep wanted me to first stick with what the manufacturer recommends. In this case we have one company, Currie, building a joint with steel components and using urethane bushings from another company. I have learned that Currie has said they have used Chevron branded and Valvoline branded grease with moly and supposedly either petroleum or synthetic is ok. All the major polyurethane bushing companies say to only use synthetic silicon based grease (which includes Teflon). So right there we have a contradiction.

After discussing this the Amsoil rep went on to recommend a number of their greases, none of which included moly or teflon, or any silicone. Greases recommended were "Racing Grease" or "Water Resistant Grease" to meet my desire for high washout resistance. He did not recommend the Polymeric Offroad Grease with moly as he didn't see my application as fitting that requirement, additionally that grease is very hard to pump and I "wouldn't be happy with it".

I called Schaeffers. That rep told me that polyurethane is not compatible with petroleum based grease, AND, is not compatible with some synthetic greases as well. All of Schaeffers grease is either petroleum based or PAO with with petroleum bases - no pure synthetics. Ultimately he had no grease to recommend for my application and stated that I should use a silicone base grease. In terms of the teflon vs moly question, he felt that either one would provide the bonding and wear characteristics I was after.

So, while I still do not have any answers I add this information into the equation. I appreciated the fact that the Schaeffer rep was upfront in saying that he did not have a grease for my application. On the other hand, the Amsoil rep implied that any number of their greases would work even though none of them had the criteria of the joint manufacturers (moly or teflon, silicone).

I'm going to call the Urethane bushing companies this afternoon. SuperLube's Silicone grease with ptfe is appearing to be a better and better choice, but I am not excited about paying $20 for a tube of grease. I am sure I will call them before this is all over to see if they recommend the silicone stuff or the cheaper multi-purpose stuff.

More later.
 
Did you you speak with Amsoil tech support or an Amsoil dealer?

For poly bushings automotive greases are not a problem. So I am not sure where Schaeffers is coming from. Most aftermarket suspension co.'s with polyurethane bushings recommend boat trailer bearing grease. I've used poly bushes with a variety of greases and seen no problem.

What I wouldn't use is a silicone grease with no EP agents. Do they say a #1 or #2 grease?
 
It was somebody at the Amsoil tech line 715-399-8324.

I have some more information to post later from some other sources.

The common silicone greases I am seeing do not specify EP (Tri-Flow, Super Lube, the fancy stuff the bushing companies sell). Maybe Dow has some EP silicone greases?

I'm kind of coming around again on this topic away from a silicone grease after talking to some people today, including 2 of the 3 bushing companies I called. I will explain my current thoughts soon.
 
Here are today's findings:

Called Mobil 1 to ask about their grease compatibility with polyurethane. Go up to a 70 year old lady at your grocery store and ask her and you will get about the same thing I got from Josh at Mobil. The most vague and unsure conversation I've ever had with a representative from any company.

I also called Chevron. He said off hand he believed that polyurethane is compatible with petroleum based grease, but he wanted to verify compatibility, which he came back on line and confirmed. So according to Chevron, polyurethane can be used with petroleum based grease.

Now for the urethane manufacturers:

Prothane (sellers of 14oz $20-25 'motion control' silicone grease)
- Would only recommend their grease for their bushings and did not deviate or elaborate beyond simply saying to use their stuff.

Daystar (sellers of 3oz $17 'lubrathane' silicone grease)
- Stated to simply use a full synthetic grease such as green grease or mobil 1, or anything really. The guy told me he doesn't even use the silicone grease and he works for Daystar!

Energy Suspension (sellers of 8oz 'formula 5' silicone grease)
- THIS IS THE COMPANY THAT MAKES THE URETHANE BUSHINGS FOR THE JOINTS IN QUESTION!
- These bushings are made from '88T' material and is very tough and impervious to most anything. He told me that I could soak the bushings in carb cleaner or just about anything and they would hold up. Therfore, he stated I can use a petroleum grease or a synthetic grease if I like.
- Did recommend either their grease for assembly - OR - stated that I could use a moly paste for assembly. He believe that is what Currie uses for assembly, either their grease or moly paste.
- Stated that silicone grease would be too thick for service greasing via the zerk fitting and again said to use any other grease of my choosing.

Summary:
Amsoil - essentially all of their greases compatible with urethane
Schaeffers - none of their grease compatible with urethane - only pure synthetic should be used
Mobil 1 - Josh needs to learn more about the products his company sells
Chevron - petroleum grease is OK for urethane
Prothane - only use their stuff
Daystar - rep doesn't even use their stuff

Two of the most important:
Currie - uses "moly lube" (applied with a brush) for assembly. Chevron and Valvoline brand names of grease with moly in it have been recommended by them.
Energy Suspension - use of moly paste or their silicone grease with teflon good for assembly, any grease synthetic or petroleum grease fine for regular servicing.

Use only silicone grease for polyurethane a myth? Would appear so.

Use only synthetic greases for use with polyurethane? Not accurate.

Petroleum grease can be used with polyurethane? Would appear so.

What a long strange trip it's been.
 
Wow, great investigative effort in the spirit of BITOG OCD nature. Too bad we don't have more grease interest here.

But, the contradictory recommendations are astounding.

How important is water wash off characteristics, since certain types are nearly water proof and might drive your decision?

It seems that Schaffer 238 moly with water proof aluminmum complex base would be perfect, yet they said otherwise.

Tell us which coin toss you decide on.

Thanks for sharing. I once tried to do this type investigation for "best brake grease" with similar results.
 
My head is still swirling a little after going from I can only use one specific type of grease to basically learning I can use any product I want. My common grease I keep on hand is Chevron Delo EP 2 (wheel bearings) and Ultra Duty EP 2 (ujoints, and steering components). But I do think I want to use a grease with moly for this. I can get Delo HD 5% moly for $4-5 a tube, but am not opposed to paying up to $10 a tube for other petro or syn brands. I have 14 of these joints on my Jeep so I would just dedicate a grease gun for them.

The application:
-very low speed of joint movement/articulation
-offroad the joints will move and articulate often
-highly loaded and subject to high impacts
-looking for moly or similar additive
-temp range 20* to 100* (no high temp requirement)
-need very low washout % (very high water resistance needed)
-used in dusty, dirty, muddy environment
-needs to be pumpable through greasable bolt zerk, but not drip all over my floor when Jeep sits in garage.
 
[re: doitmyself]

I could go with a Schaeffers grease.

An AL thickener complex would seem good for the high water resistance properties I am after. However, I look at the #238 for instance and see a water washout % of 5.5% on the nlgi2. Or Schaeffer #274M2 with a water washout of 5.4%. Where as lithium complex from Delo HD 5% moly is 4% washout. Not that I would let such a small difference make the decision, but it would be something to consider when paying double for one grease over the other when a key property is virtually the same.

Amsoil Water Resistant (GWR) is a lithium complex base with a 3.5% water washout, which is the best among most of the greases I would be considering, but again, I don't know if .5% or even 1% is really going to make my decision for me.

Edit - kind of strange, but the Amsoil Multi-Purpose grease has a better water washout figure of just 1.8% (no spec on spray off).

Now water spray off is very strong on that Amsoil Water Resistant (GWR) grease, 8.5% vs the Delo HD 5% moly of 20%. That would be something to really weigh, however the fastest moving water this joint will ever be subjected to is a fast moving stream that comes up to my door opening. High spray off resistance is good, but I don't know if it applies for me.
 
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Amsoil guys? What happened to Synthetic Heavy-Duty Grease NLGI#2 GC/LB (GHD)? Was that grease replaced with something else? GHD grease was moly fortified, now the only grease Amsoil has with moly is the polymeric (the only grease Amsoil tech said not to use - poor pumpability?)
 
Go buy CAT Desert Gold and be happy.

Semisyn with lots of moly.

If the bushings use a zirk then finding silicone grease in a tube will be an issue. Polyurethane caster wheels are used for oil resistant situations so as Energy stated, oil on poly is not an issue.

Conventional EP adds won't help much in this case because they will only "activate" with the heat and pressure of metal on metal contact (short version). Teflon, moly and other solid lubes will help in this case.

I think silicone is just fine for this but is not really necessary, also see above for availability.
 
I wonder if the water washout and spray tests do not correlate with water insoluble properties? I.E., silicone grease in your palm will simply not mix with water 100%.....just tried Super Lube, it turned white indicating some H2O take up, lithium complex takes on water readily.

I could never understand how Mystic gets less that 2.5% washout numbers with lithium complex (known to absorb water) compared to other marine greases with aluminum complex or other bases.

The product Tempest lists seems to have everything you want, which seems to be high water insolubility and high moly...5% unless you go to some specialty app.. The specialty greases you listed above might use silicone for it's water insolubility for immersion service???
 
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I am learning alot about grease.

I'm guessing the lithium complex greases have more additives in them to make them more resistant to washout. More additives likely means less base oil, where as the aluminum complexes can inherently withstand water washout better without extra additives which reduces the base oil in the grease.

I would really like to have a local source for the grease. I have Amsoil distributor not too far away. Schaeffers is pretty far. CAT dealer isn't that close, but not terribly far. I have Chevron dist right down the road that I already deal with.

One big thing is I won't be buying cases. 4 tubes would probably last me 2 years, so I need to find somebody from Amsoil or Schaeffer who will sell tubes vs cases. Naturally I could buy tubes individually at Chevron and probably CAT.

Not too excited about the lithium complexes in the Chevron moly grease, but price and availability can't be beat. AL complex would be more ideal, but more expensive and harder to get. Cal complex (CAT), not as convienent either.

Still pondering. Probably putting too much thought in this thing.
 
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Quote:
Probably putting too much thought in this thing.


thumbsup2.gif


Only reason to put this much thought into it is if you are really going to expose this to extreme use and lots of water. The CAT grease I mentioned will handle either.

You can buy Amsoil right off the website in single tubes. Contact Pablo on this site before hand so you can use a site sponsor.

I used silicone dielectric grease when I replaced the bushings on my truck with Moog "rubber" parts. So far so good. The factory parts didn't seem to have any grease at all...

"Convenient" only matters if you will be switching greases a lot.
 
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