Moly Grease?
- Thread starter chooch
- Start date
All metals, even highly polished parts, have what is called asperities. These are simply rough bumps or craters at the microscopic level. For many metal to metal contact surfaces a simple coating, or film, of oil or grease is all that is needed to keep these asperities seperated. When the speed or the load of the contact becomes too great, these asperities can actually rupture the film that the grease or oil has provided. Once this happens the asperities tend to "cold-weld" to each other. After that they will tend to break each other off reforming new craters in the process. Once asperities start rupturing they will contaminate the fluid field that is supposed to protect the surfaces. These broken asperities will also quicklly oxidize and further help contaminate the fluid film. This is when the wear begins.
In certain circumstances of high speed or high load, greases will incorporate lubricating solids such as molybdenum disalfate. These solids will help to seperate the metals from each other and have a natural affinity for the metal surfaces. Lubricating solids will also help to distribute the load better than a plain oil film. (when I talk oil, I'm also taking grease because grease is simply oil with a soap thickner) In other words, when you have a friction area that is subject to high speed or load, the solids will fill in the asperities or "craters" and help to keep the metals seperated from one another without deforming.
Other greases such as straight lithium base will do the job, and yes you must lubricate more often an area that has been designated as an area needing lubricating solids such as moly. You can find moly grease right next to straight lithium base grease in any K-mart or auto parts store. Why not just use what your manual calls for?
Eric, not a flame, but I think you will find that there is no difference in the "drop point" (or when the grease turns to liquid state) of regular lithium base grease and a lithium base grease with molybdenum. You can, however, purchase greases with a higher drop point. The containing of moly has nothing to do with the drop point, although when a moly grease does reach it's drop point, the oil will be the first thing to run out. As I stated before, the moly has a natural affinity for the metal surfaces and will be the last thing to leave.
In certain circumstances of high speed or high load, greases will incorporate lubricating solids such as molybdenum disalfate. These solids will help to seperate the metals from each other and have a natural affinity for the metal surfaces. Lubricating solids will also help to distribute the load better than a plain oil film. (when I talk oil, I'm also taking grease because grease is simply oil with a soap thickner) In other words, when you have a friction area that is subject to high speed or load, the solids will fill in the asperities or "craters" and help to keep the metals seperated from one another without deforming.
Other greases such as straight lithium base will do the job, and yes you must lubricate more often an area that has been designated as an area needing lubricating solids such as moly. You can find moly grease right next to straight lithium base grease in any K-mart or auto parts store. Why not just use what your manual calls for?
Eric, not a flame, but I think you will find that there is no difference in the "drop point" (or when the grease turns to liquid state) of regular lithium base grease and a lithium base grease with molybdenum. You can, however, purchase greases with a higher drop point. The containing of moly has nothing to do with the drop point, although when a moly grease does reach it's drop point, the oil will be the first thing to run out. As I stated before, the moly has a natural affinity for the metal surfaces and will be the last thing to leave.
Last edited:
EricGorr
Super Power AssClown
- Aug 24, 2000
- 708
- 1
Thanks Jaybird, thats what I'm hoping to see in this forum is more people with technical experience and information on a particular subject. The only thing I'd add is that Moly grease is cheap and easy to get at farm supply stores, and that the most important thing is to periodically grease the bearings of a dirt bike.
Thanks guys!
Thanks guys!
Not quite true, yarpro....
When dealing with two different types of grease bases things can happen when you mix them. Most often the moly grease that you will find at most supply stores is of a lithium base. It will be basically the same as the lithium grease sitting next to it only with moly added. Mixing the two will not have any adverse effect, if the two greases are already of the same thickness. (NLGI #2, etc...)
Now when you have two different base greases like lithium vs 100% synthetic, then mixing them can make the mixture soft. It won't hurt the lubricating aspects of either grease, but the two greases mixed together will can sometimes end up being a softer compound than either of the two greases were when they were seperate, and the mixture won't last as long.
Bottom line is, it won't hurt to mix greases but it is best not to.
Like Eric stated, periodic lubing of bike bearings is the most important thing.
One thing I want to add...NEVER use a grease that has a calcium compound.
Calcium compound greases demand being replentished on a frequent basis and if they aren't the base stock will harden like concrete once the oil has left the soap. It's not a pretty sight to see.
When dealing with two different types of grease bases things can happen when you mix them. Most often the moly grease that you will find at most supply stores is of a lithium base. It will be basically the same as the lithium grease sitting next to it only with moly added. Mixing the two will not have any adverse effect, if the two greases are already of the same thickness. (NLGI #2, etc...)
Now when you have two different base greases like lithium vs 100% synthetic, then mixing them can make the mixture soft. It won't hurt the lubricating aspects of either grease, but the two greases mixed together will can sometimes end up being a softer compound than either of the two greases were when they were seperate, and the mixture won't last as long.
Bottom line is, it won't hurt to mix greases but it is best not to.
Like Eric stated, periodic lubing of bike bearings is the most important thing.
One thing I want to add...NEVER use a grease that has a calcium compound.
Calcium compound greases demand being replentished on a frequent basis and if they aren't the base stock will harden like concrete once the oil has left the soap. It's not a pretty sight to see.
MO-dirt-AR
Member
- Nov 6, 2001
- 39
- 0
'02 YZ250 manual also calls for "molybdenum disulfide OIL" for the power valve. the manual differentiates the moly D oil from "engine mixing oil" and "transmission oil".
question?? what oils meet this moly D requirement and where to buy them?? when I look at the oil qts at the auto store I don't see any mention of moly D.
thanks for any replies.
question?? what oils meet this moly D requirement and where to buy them?? when I look at the oil qts at the auto store I don't see any mention of moly D.
thanks for any replies.
MO,
Try looking at aerosol cans of lubricant. I think Gunk has a moly spray oil.
If you can find any industrial way oils, they will serve the purpose and most have added polymers to help it stay put.
Try looking at aerosol cans of lubricant. I think Gunk has a moly spray oil.
If you can find any industrial way oils, they will serve the purpose and most have added polymers to help it stay put.
MO-dirt-AR
Member
- Nov 6, 2001
- 39
- 0
I found this website
http://www.mrmoly.com/catalog.html
that seems to fit the bill for the YZ250 powervalve lubricating with moly D oil.
I was wondering which product would be best for the YZ250 powervalve?
the "Penetrates/Lubricates/Dries - Fluid aerosal-spray lubricant designed to remove moisture, penetrate and release, lubricate, protect from corrosion, and clean." OR
"A.D.F. is ideal for engine part preassembly treatment, gears and slides, rings and pinions, bearings, timing chains, and valve components. A.D.F. will inhibit rust and corrosion, penetrate hidden places, and lengthen component life." OR
"L.Q.D. penetrates hidden places, does not flow or drain, eliminates noise and vibration, and has long-term effectiveness. L.Q.D. is ideal for control linkages, gear units, flexible drives, pivots, gear trains, etc."
OR
just the oil additive "Engine supplement that reduces friction and wear, lowers oil temperature, protects from corrosion, reduces fuel consumption, and prolongs engine life."
thanks
AR
http://www.mrmoly.com/catalog.html
that seems to fit the bill for the YZ250 powervalve lubricating with moly D oil.
I was wondering which product would be best for the YZ250 powervalve?
the "Penetrates/Lubricates/Dries - Fluid aerosal-spray lubricant designed to remove moisture, penetrate and release, lubricate, protect from corrosion, and clean." OR
"A.D.F. is ideal for engine part preassembly treatment, gears and slides, rings and pinions, bearings, timing chains, and valve components. A.D.F. will inhibit rust and corrosion, penetrate hidden places, and lengthen component life." OR
"L.Q.D. penetrates hidden places, does not flow or drain, eliminates noise and vibration, and has long-term effectiveness. L.Q.D. is ideal for control linkages, gear units, flexible drives, pivots, gear trains, etc."
OR
just the oil additive "Engine supplement that reduces friction and wear, lowers oil temperature, protects from corrosion, reduces fuel consumption, and prolongs engine life."
thanks
AR
MO-dirt-AR
Member
- Nov 6, 2001
- 39
- 0
I reviewed the YZ250P owner's manual diagram for the power valve, and it calls for the MolyD oil on only two of the power valve parts, so I am leaning to the engine oil additive VS. the spray products.
Jaybird, I`m just curious how come you know so much about Lubricants? I work at Ocean State Oil we are the largest lubricants distributor in southern New England. We sell Shell, Chevron, Texaco, Kendall, Sunoco, Havoline and we blend our own line of industrial lubricants.
MikeKX250....
I don't know squat about lubricants....
but I DID stay at a Holiday Inn Express last night!
:debil:
I don't know squat about lubricants....
but I DID stay at a Holiday Inn Express last night!
:debil:
Jaybird,
I don’t know how I missed this post. Great explanation on moly grease.
What about using a synthetic based Teflon grease for high load areas like the shock linkage? I have been using Super Lube Grease http://www.super-lube.com/desc.html for a while now and have had good luck but you make some interesting points about the moly particles in moly grease. Wouldn’t Teflon give you the same protection? I realize PTFE is a soft compound but seems that it would fill in the surface irregularities and give you the same protection.
BTW, Super Lube grease is high temp, water proof and doesn’t attract a lot of dirt. I use it anywhere any type of grease is specified.
I don’t know how I missed this post. Great explanation on moly grease.
What about using a synthetic based Teflon grease for high load areas like the shock linkage? I have been using Super Lube Grease http://www.super-lube.com/desc.html for a while now and have had good luck but you make some interesting points about the moly particles in moly grease. Wouldn’t Teflon give you the same protection? I realize PTFE is a soft compound but seems that it would fill in the surface irregularities and give you the same protection.
BTW, Super Lube grease is high temp, water proof and doesn’t attract a lot of dirt. I use it anywhere any type of grease is specified.
RM_guy,
Yes, teflon will serve the purpose well. It will perform with very similar results as moly. Molybdenum disalfide has some differnt things going on at the molecular level than teflon, but both will carry a load well and at higher temps.
Remember, the guy who uses trash grease often will have longer lasting bearings than the guy who greases with high dollar stuff on occasion.
Yes, teflon will serve the purpose well. It will perform with very similar results as moly. Molybdenum disalfide has some differnt things going on at the molecular level than teflon, but both will carry a load well and at higher temps.
Remember, the guy who uses trash grease often will have longer lasting bearings than the guy who greases with high dollar stuff on occasion.
Thanks Jaybird. I agree with your comment about using cheap grease more often. I get a very good deal on the Super Lube (how's free sound?) and I grease frequently because I hate to replace bearings.:(
