High moly grease and tapered roller bearings

[wrcsixeight]

Years ago I got in new brembo rotors and put New 'made in Mexico' SKF bearings and races into them using valvoline Synpower grease which is a high moly grease. Recently i have been hearing a bearing type of noise, audible mostly at slower speeds, and convinced myself it was from driver's side front wheel bearings. I replaced the drivers side today. After cleaning the old ones with a toothbrush and gasoline, I can see absolutely nothing wrong with the rollers. no visible flatspots from moly sliding, cant feel any roughness when spinning them in the races. The races have some lines in them that cannot be felt. I installed the new SKF bearings( made in China) despite the old ones looking to be in very good conditions, and the noise appears to be 60% less, but this is also what I wanted to hear, so i am not saying for sure that the noise is mitigated 60% with just the drivers side bearings replaced, My ears are a bit stuffed from surfing today. I am doubtful the noise I was hearing could be from these nearly pristine looking rollers. So say there has been some sliding/ flat spotting of the rollers going on, one would expect any moly induced sliding flat spotting of the rollers to be visible to the a pair of 2x reading glasses, no? While i still have some Synpower grease left over, I used red masterpro high temp wheel bearing grease from Oreilleys on the new bearings Not sure if it has moly or not, but I assume no as it is clearish red, not chalky red like redline CV-2 and valvoline synpower is nearly black. Thoughts?

 

[Trav]

Up to 3% they claim is okay the 5% is not recommended, the valvoline Synpower grease you used I don't believe is 5%. Personally I use none just Mobil 1 red synthetic, you know the one everyone hates because it drips out of gun. It is good wheel bearing grease. I most be the only one that has no trouble with it dripping with a plastic bag on the bottom. LOL

 

[Kestas]

I've never heard of roller flat spotting in wheel bearings just from the choice in grease.

 

[Trav]

Just going by what the grease manufacturers publish with the product eg Schaeffer's 238 5%.

Quote

Ultra Supreme is one of our tackiest greases; it should not be used in passenger car automotive wheel bearings and electric motor bearings.

Cat and others seem have the same or similar warning on their 5%.

 

[maxdustington]

Originally Posted by wrcsixeight

Years ago I got in new brembo rotors and put New 'made in Mexico' SKF bearings and races into them using valvoline Synpower grease which is a high moly grease. Recently i have been hearing a bearing type of noise, audible mostly at slower speeds, and convinced myself it was from driver's side front wheel bearings. I replaced the drivers side today. After cleaning the old ones with a toothbrush and gasoline, I can see absolutely nothing wrong with the rollers. no visible flatspots from moly sliding, cant feel any roughness when spinning them in the races. The races have some lines in them that cannot be felt. I installed the new SKF bearings( made in China) despite the old ones looking to be in very good conditions, and the noise appears to be 60% less, but this is also what I wanted to hear, so i am not saying for sure that the noise is mitigated 60% with just the drivers side bearings replaced, My ears are a bit stuffed from surfing today. I am doubtful the noise I was hearing could be from these nearly pristine looking rollers. So say there has been some sliding/ flat spotting of the rollers going on, one would expect any moly induced sliding flat spotting of the rollers to be visible to the a pair of 2x reading glasses, no? While i still have some Synpower grease left over, I used red masterpro high temp wheel bearing grease from Oreilleys on the new bearings Not sure if it has moly or not, but I assume no as it is clearish red, not chalky red like redline CV-2 and valvoline synpower is nearly black. Thoughts?

I had the exact same issue last year, I had all the symptoms of a bad bearing and went through a long ordeal ordering the tools to change it. It was LOUD and when I went to change it, it looked perfectly fine albeit destroyed from removal. The sound went away but the bearing appeared to have nothing wrong with it. I replaced mine with a SKF made in SK.

 

[wrcsixeight]

Well the noise is definitely 40 to 60% less than before, with new bearings on one side. I'll have to try and get some good macro pictures of the rollers and races and see if they reveal what my 2x reading glasses could not. I've no idea what is goig on, i really expected to find obvious flat spotted rollers or other damage, as that is what it sounded and felt like. Imminent failure does not seem like it was coming anytime soon, but I can't ignore such noises, and will be putting on lots of mileage in the next few months. I do not know what percentage of moly Synpower is, and cannot find the links, but there are a few seemingly creidble stories out there saying that premature wheel bearing and U joint failures stopped when moly free greases were used in those applications.

 

[Trav]

I was taught many years ago never use moly in U joints or wheel bearings. I never questioned it or used it until many years later and I still don't use it.

 

[barryh]

I've also heard that moly grease should not be use in roller bearings, something about the rollers skidding rather than rotating.

 

[Purpfox]

Yes, Most moly greases are for sliding applications. I would recommend a Lithium complex grease.

 

[buck91]

Synpower, I believe, is 1% moly. So yes it uses some but not what I would call a high moly grease. Valvoline does endorse it for all auto applications including wheel bearings, u-joints and even CV joints. I use it as a chassis grease and <span style="font-style: italic">prefere</span> non-moly for bearings but it wouldn't bother me using this in a pinch. None of my current fleet has greasable wheel bearings by design, though. Excluding bicycles.

 

[vssjim]

What I always find funny is that the Valvoline ford grease is made with moly as they advertise it with moly and it was made to help ford stop having wheel bearing failures in the seventies when disc brakes became a big deal in American cars , so like always I'm confused as they advertise wheel bearings and u-joints along with chassis. I used to use this product in a construction fleet which is every type of grease needed joint you can imagine from small to large with no problems except getting the operators to grease there machine.

 

[SargeBB]

I begin not using grease containing Moly in the old fashioned wheel bearings that are to be repacked at about 15-20,000 miles and not using moly in universal joints back in the mid 1990's when I had a wheel bearing replaced under Ford's 36,000 warranty. It was replaced with a Ford u-joint (no zerk) packed with the Ford spec. moly. When that joint failed no warranty remained so I bought a Spicer with a zerk. When I sold the Ford 4x4 the joint had well over 50,000 miles and no more problems with that joint. The mechanic showed me the original joint and the needle bearings had turned to powder. I do like moly, but for truck use, I reserve it for non-roller bearing use. Mystik Jt-6 Hi-Temp LC #2 and Chevron Delo LC #2 are 2 great greases I use, but there are also many other excellent heavy-duty LC greases in #2 that do not contain moly such as GM spec. Valvoline and Mobil-1. A decade or so back, George Morrison wrote some excellent posts in these pages, or Tacoma World or Tundra Solutions on avoiding moly for the above-mentioned uses.