Krytox for Car Wheel Bearings

[fsaid92]

Scored a deal on 0.5kg of Krytox GPL 223 ($51.36 on Amazon before it jumped to $143.64).

It'll be used for the wheel bearings all around. Front is conventional ball bearing, open so no built in seal to worry about damaging. Rear is a pair of taper roller bearings in the drum.

I remember reading because this stuff is dense, less is supposed to be used. Can anyone clarify on this?

 

[eljefino]

Isn't that for scuba diving and oxygen systems?

 

[fsaid92]

Maybe a grade of it is used for scuba. I'm no scuba expert.

Straight from the sell sheet: "The GPL 22X series contains sodium nitrite corrosion/anti-wear inhibitor and is ideal for corrosive environments where there is no danger of the sodium nitrite additive reacting with chemicals or causing contamination problems. Typical applications are automotive bearings, sealed pump bearings, electric motor bearings and general purpose bearings."

I know enough that too much or too little lube will affect bearing life. The question is how much is too much/too little? Should the bearing be packed by volume or mass?

 

[philipp10]

A very expensive wheel bearing grease for sure. Not sure I see it as worth the cost. We use it where I work in non-automotive applications.

 

[JHZR2]

Can't say that I see the benefit.

But if there is a difference, you'll probably want to try to pull either an application guide to help identify the delta, or attempt to pull bulk density numbers and see how they compare.

 

[fsaid92]

Yes I'm aware that it's an expensive grease at normal prices. I paid $50 for the tub not $260 like it sells for elsewhere. Ignore the money aspect; I already have the grease.

https://www.youtube.com/watch?v=97xYjQSTCow

This is the video I'm referring to when it comes to filling. They say 15-80% original volume, and to consult the manufacturer for weight filling due to the density.

 

[edhackett]

223 uses an ISO 32 base oil. That's equivalent to SAE 8 motor oil. Typically automotive wheel bearing greases use an ISO 220 base oil. That's equivalent to SAE 50 motor oil.

The 22X series does contain greases that would be appropriate for wheel bearings. 226 uses an ISO 220 base oil. The 21X series are the extreme pressure greases, the type used for automotive/machinery grease.

I wouldn't use 223 in wheel bearings, it's just not the right grease for the job.

http://www2.dupont.com/Lubricants/en_US/assets/downloads/H-58510-5_Krytox_Typical_Properties.pdf

Ed

 

[spackard]

Their K-22116 app note seems to me to say volume filling is the same as other greases; filling by weight is different. In the app note they have some calculations to do for getting your DN value, then how much grease to use. Also, seems to me it is concerned with roller bearings, not tapered wheel bearings.
Could always contact them to see what they suggest: [email protected]

 

[Yah-Tah-Hey]

How did we live without that product for so many years? I feel deprived.

 

[bullwinkle]

It's good stuff, it can take a lot of heat without burning up or drying out. It would be interesting to see if any MPG increase results from using it.

 

[philipp10]

Originally Posted by bullwinkle
It's good stuff, it can take a lot of heat without burning up or drying out. It would be interesting to see if any MPG increase results from using it.


nothing measurable without laboratory equipment. If it did increase mileage, a wheel bearing with normal grease would be burning up....

 

[Hootbro]

Originally Posted by Yah-Tah-Hey
How did we live without that product for so many years? I feel deprived.


You are deprived because Krytox range of greases are for highly specialized and narrow applications and not a general servicing grease. You will find it is used more in the manufacturing of a item that is a one time application for the life of the product. We use it at work in aviation manufacturing for few specialized application as a servo and electric motor assembly lubrication but there is a hundred other applications it is used for. The stuff is usually prohibitively expensive and nothing you will see on the Auto Parts Store shelf or your local Walmart and have to buy from industrial supply houses most times.

 

[MolaKule]

Originally Posted by edhackett
223 uses an ISO 32 base oil. That's equivalent to SAE 8 motor oil. Typically automotive wheel bearing greases use an ISO 220 base oil. That's equivalent to SAE 50 motor oil.

The 22X series does contain greases that would be appropriate for wheel bearings. 226 uses an ISO 220 base oil. The 21X series are the extreme pressure greases, the type used for automotive/machinery grease.

I wouldn't use 223 in wheel bearings, it's just not the right grease for the job.

http://www2.dupont.com/Lubricants/en_US/assets/downloads/H-58510-5_Krytox_Typical_Properties.pdf

Ed

And clean the bearing assembly before using a new grease as some greases are NOT compatible.

 

[A_Harman]

We used Krytox grease to lubricate the valvetrain in Cummins C-series engines when we were doing oil consumption testing. We blocked off the pressurized oil supply passages to the overhead, and lubricated the rocker arm pivots, tips, and pushrod ends with Krytox. Then we ran the engine at idle to compare oil consumption with the engine oil system configured normally. We would typically run the oil consumption tests for 4 days to get a steady, verified rate. What we found was that more than half of the oil consumption at idle was due to oil being sucked down the valve guides. The Krytox grease lubricated the overhead OK in the tests, but we never tried to run the engine above idle speed with the oil turned off to the valvetrain. Ultimately, we developed a valve stem seal design that eliminated oil consumption at throttled conditions. The diesel valve stem seals were just no good for that.

 

[Purpfox]

Fair warning. krytox is incompatible with everything except other fluorinated greases. we had many failures at our site when knuckleheads would try and run it in other places.

 

[nthach]

Originally Posted by eljefino
Isn't that for scuba diving and oxygen systems?

Scubapro and I also think Aqualung and Mares calls for Christolube MGC-111, Krytox grease is in the same vein(fluoropolymer/fluoroether thickened with PTFE).

It's a expensive, specialized lubricant used in places where the risk of contamination is too great or when a filled-for-life, extreme conditions lubricant is required.

Finish Line is also reselling Krytox from Chemours as a super-high end bike grease and unless it's going to be used for the threaded couplings of a travel bike or ceramic bearings it's a gimmick. http://www.finishlineusa.com/products/bicycle-greases/extreme-fluoro-grease

/edit - some of the automakers call for Krytox oil to be used to help reduce squeaking noises from rubber on rubber contact and on convertible tops/hard tops. GM and Mercedes do have Krytox oil listed in their parts systems.

 

[a2gtinut]

From Dupont
The GPL 21X series contains molybdenum disulfide for
extreme pressure (EP) conditions and should be used
for slow speed or heavily loaded applications where
there is no danger of the molybdenum disulfide additive
reacting with chemicals or causing contamination.
Typical applications include highly loaded gears,
CV joints, U-joints, splined shafts, and commercial
electrical switches.

The GPL 22X series contains sodium nitrite corrosion/
anti-wear inhibitor and is ideal for corrosive
environments where there is no danger of the sodium
nitrite additive reacting with chemicals or causing
contamination problems.
Typical applications are automotive bearings, sealed
pump bearings, electric motor bearings, and generalpurpose
bearings.