Bearing questions, maintenance replacement etc

[Ray87]

Hi.

Just picked up a pre owned kraton 8s, truck is not much used at all guessing 15-220 packs maximum. Want to tear it appart and start with maintenance, replace all diff oils etc to know what i have

What is the best to do with bearings?
Should i open them and clean them? If so what could i use to do it with? Someone use wd40 but would not that make it too sticky for dirt?

What is best to lubricate them with? I have this oil from hudy, should i use it?
https://www.rccarshop.co.uk/dy106230-hudy-bearing-oil-p

Is there a risk to destroy the bearing when one open it? I don't have any spare and i struggle to find new one from arrma when it comes to the one on the diff output 12x24x6mm.

Seems like the truck have most of the same sized bearings like traxxas but not on the diff, only thing i found in stock nearby was same size bearing from a electric skateboard, is that ok use or should i get something that is ment for RC? Since one need to open the diff completly to remove this two bearings i want something that last if i need to replace them.

Personaly i have just runned all my rc back in time and never cleaned or oiled them, just replaced them as they breaked. What should i do this time around for the bearings that require some time to replace like the one on the diffs?

Cheers

 

[SrC]

There may be a learning curve if your first time cleaning out the BB's. Watch videos. You learn by doing it. Becomes so easy, during a disassembly for BB maintenance. Buy a full set of BB's to always have on hand, along with Diff and shock oils.
I service my BB's by removing both outer rubber shields with an exacto knife. Spray clean with any automotive brake spray/solvent. I never use Regular WD40. It is not a lube and leaves a film that gums up and ruins them. Brake spray evaporates quick. then I place a small amount of automotive grease in them. Only fill 1/4-1/3 if even that. My preference is Superlube Syn. grease. Too much grease packed in will make it gall out and fail. Less is more. Then pop the rubber seals back in place. I do this when my BB's are brand new and maybe one more time in their life, Then replace. Many just prefer to replace BB's. Thats your call.
You need specific BB's for these models. I noticed some New BB's out the package are often Dry as a bone. They fail much faster. So I always remove the grease they have and use my own. Again, less is more. Or too packed, the BB actually locks up and runs hot, Then it explodes.
I only use oil on my 2 motor BB's. A drop on each one. High temp Synthetic oil. Don't neglect motor maintenance at all. Many do and those 8s motors get pricey, when neglected. BLX motors can last for many years if maintained well and worn loose BB's replaced, Before they explode. Or causing a bricked motor.
I like to use SuperLube Syn Oil on the motor BB's. But any Syn. high temp oil is fine. AMZ sells Liberty RC Syn oil also. A bit thinner than Superlube, that's all. I have both here.
Any Automotive Grease is generally fine in your Chassis BB's and also on the Fr and Rr Diff main gears.
Only Motor BB's get a drop of oil. For cleaning out the motor and their BB's, use any automotive Electrical Contact spray. It's way safer on Motors than Brake spray. This is important.

 

[Ray87]

There may be a learning curve if your first time cleaning out the BB's. Watch videos. You learn by doing it. Becomes so easy, during a disassembly for BB maintenance. Buy a full set of BB's to always have on hand, along with Diff and shock oils.
I service my BB's by removing both outer rubber shields with an exacto knife. Spray clean with any automotive brake spray/solvent. I never use Regular WD40. It is not a lube and leaves a film that gums up and ruins them. Brake spray evaporates quick. then I place a small amount of automotive grease in them. Only fill 1/4-1/3 if even that. My preference is Superlube Syn. grease. Too much grease packed in will make it gall out and fail. Less is more. Then pop the rubber seals back in place. I do this when my BB's are brand new and maybe one more time in their life, Then replace. Many just prefer to replace BB's. Thats your call.
You need specific BB's for these models. I noticed some New BB's out the package are often Dry as a bone. They fail much faster. So I always remove the grease they have and use my own. Again, less is more. Or too packed, the BB actually locks up and runs hot, Then it explodes.
I only use oil on my 2 motor BB's. A drop on each one. High temp Synthetic oil. Don't neglect motor maintenance at all. Many do and those 8s motors get pricey, when neglected. BLX motors can last for many years if maintained well and worn loose BB's replaced, Before they explode. Or causing a bricked motor.
I like to use SuperLube Syn Oil on the motor BB's. But any Syn. high temp oil is fine. AMZ sells Liberty RC Syn oil also. A bit thinner than Superlube, that's all. I have both here.
Any Automotive Grease is generally fine in your Chassis BB's and also on the Fr and Rr Diff main gears.
Only Motor BB's get a drop of oil. For cleaning out the motor and their BB's, use any automotive Electrical Contact spray. It's way safer on Motors than Brake spray. This is important.

Thank you for the advice, i would buy a random brake cleaner for automotive and clean them before lubing.

I found a 400ml tube of lithium grease that can hold 140c/284f is this grease good enough for bearings and the main diff gears?
It is a mineral oil in this grease.

Could always order bearing grease and diff grease at hobby store but it take some time to get it during the summertime, and they cost like 10 dollar for like 5g of grease vs 400g in the automobile store.

Edit: i cant find a grease with syntetic oil, what happens if i use one that is mineral? Not good for plastic?
Also read that silicone grease is not good for hard metal to metal?

Would be great to find a grease that can fit both bearings and ring gears

 

[RudyD54]

I use one of these to blast the crud out of the bearings....pretty effective: bearing blaster

 

[Ray87]

I see that the bearings in the diff is metal shielded, are they just as easy to open?

Also wonder if i can use the litium grease that have mineral oil in it for the gear outside the diff and the bearings? They should hold a heat up to 140c/284f but it’s a cheap grease from a multi tool store.

 

[fish]

 

[SrC]

I see that the bearings in the diff is metal shielded, are they just as easy to open?

Also wonder if i can use the litium grease that have mineral oil in it for the gear outside the diff and the bearings? They should hold a heat up to 140c/284f but it’s a cheap grease from a multi tool store.

Any Automotive grade grease, for ball joints, Car Bearings and such is what you really want. Local hobby shops have something but yeah expensive for what you get, a tiniest amount for a high price like it is Gold or something. Get a NLGI rated grease whereve you find it. Not hard . Read the label, It will say. Found at any Auto parts store. Mobil One is a Synthetic grease FWIW. Maybe your Lithium grease is NLGI rated? look closely.
No sure what you have in your area. Anything for Autos is ok. Google NLGI grease.

>>>Metal "Shielded" BB's do not come apart. Don't even attempt it. There is a distinct difference between Rubber Sealed and metal shielded. Rubber seals Are removeable . Plain Metal Shields are Permanent. Shields do not Seal the BB. Always repace with Rubber sealed BB's. Shielded are best in Motors. Less friction to them, but are more exposed to dirt.
Just buy a set of Rubber Sealed BB's, to have on hand.
Best you can do with Shielded is spray flush them well, and oil them or spray a lube into them. Shielded BB's don't last as long. Except inside a motor, where they perform better and dirt ingress is much less. Only use Motor specific BB's when replacing them, if you do.

 

[Ray87]

View attachment 311655

Thanks for the video, been a while since i watched that channel

So this guy use oil and not grease i see, so a few drops of bearing oil do the trick but it wont last as long as the grease i guess, what is the best to use considering it could suck up dirt easier with grease?

View attachment 311655

Thanks for the video, been a while since i watched this channel he have good videos.

I see he use oil and not grease. Grease would last longer but oil making less dirt sticking into it?

 

[SrC]

I use one of these to blast the crud out of the bearings....pretty effective: bearing blaster

Been using the Bearing Blaster from RPM for like 30 years. They make 2 sizes. Indespensible IMHO. If you like servicing BB's. Years back, BB's were Very expensive to replace. Easily $100.00 a set. So most always serviced them often. Now they are so cheap for a kit that many never even clean them. Just replacing them when they fail. I try to avoid exploding BB's, as it can mess up parts like diffs/ hubs, etc when they do explode. By servicing them often enough you will catch that one or 2 BB's that are too worn to reuse , and just toss them.
How I fly.

Thanks for the video, been a while since i watched that channel

So this guy use oil and not grease i see, so a few drops of bearing oil do the trick but it wont last as long as the grease i guess, what is the best to use considering it could suck up dirt easier with grease?

Thanks for the video, been a while since i watched this channel he have good videos.

I see he use oil and not grease. Grease would last longer but oil making less dirt sticking into it?

If Speed running in a cleaner environment on pavement Oiling the BB's is ok. For least friction, most speed, reducing Amp draw. The BB's are still shorter lived at the sacrifice of this Speed running. A given.
But for any general off roading/ Bashing Grease is an an absolute must, period. Using oil here is just being lazy IMHO. Oil seeps out and attracts more dirt than a grease would. So Oiling BB's always makes them very shortlived. The BB "Cages" will eventually push out and the BB explodes apart.
>>>99% of New Replacement BB's always come pre-packed with1/4-1/3 Grease. And no more. I only Oil Motor BB's, as stated earlier. And Greasing Motor BB's will ruin the motor making it run way hotter. Motor specific BB's come oiled, for this reason. Whether Ceramic ones or not.

I don't agree with that URC video. Not just with using Oil instead of grease. I always pry up the rubber seal from/At the inner race. From the outer race damages the rubber seal. Otherwise Outer BB's Race rotates and spins when replaced back from the seal damage. . Only the Inner race should spin around/within the seal like when it is new.

Look to many other videos also. And after a while you will see the whys and why not to do it a certain way.
The rest you learn by doing, and observing your results.

 

[Ray87]

Any Automotive grade grease, for ball joints, Car Bearings and such is what you really want. Local hobby shops have something but yeah expensive for what you get, a tiniest amount for a high price like it is Gold or something. Get a NLGI rated grease whereve you find it. Not hard . Read the label, It will say. Found at any Auto parts store. Mobil One is a Synthetic grease FWIW. Maybe your Lithium grease is NLGI rated? look closely.
No sure what you have in your area. Anything for Autos is ok. Google NLGI grease.

>>>Metal "Shielded" BB's do not come apart. Don't even attempt it. There is a distinct difference between Rubber Sealed and metal shielded. Rubber seals Are removeable . Plain Metal Shields are Permanent. Shields do not Seal the BB. Always repace with Rubber sealed BB's. Shielded are best in Motors. Less friction to them, but are more exposed to dirt.
Just buy a set of Rubber Sealed BB's, to have on hand.
Best you can do with Shielded is spray flush them well, and oil them or spray a lube into them. Shielded BB's don't last as long. Except inside a motor, where they perform better and dirt ingress is much less. Only use Motor specific BB's when replacing them, if you do.

Thank you for good help! And saving me the trouble for trying to open them.

One of them is a bit hard to spin so i will try to spray them from outside and clean it, do you recomend me to use a crc electric motor cleaner spray or should i just buy automobile brake cleaner?

Think i just order a pack from jimsbearings, it would cost me 2x price with tax paper plus 25% but it would be worth it and still cheap, cant even find the diff bearing here at all, i can find is same size from hpi but they are sold out, do you know if jimsbearings have same quality as the stock? Only 11 dollar for two arrma bearings or you can pay 35 dollar for every single bearings from Jim.

Another question for you, i just opened the center diff but two of the screws is stuckt because of this soaking loctite issue from factory. Could i use a storm lighter to heat them up? For about how long is enough to heat them? Should the flame be directly on the screw head or on the diffcase? Just affraid they can be too heated and becoming weak. don't want to wait 2-4 weeks on a new diff case if it goes south….

 

[fish]

Any Automotive grade grease, for ball joints, Car Bearings and such is what you really want. Local hobby shops have something but yeah expensive for what you get, a tiniest amount for a high price like it is Gold or something. Get a NLGI rated grease whereve you find it. Not hard . Read the label, It will say. Found at any Auto parts store. Mobil One is a Synthetic grease FWIW. Maybe your Lithium grease is NLGI rated? look closely.
No sure what you have in your area. Anything for Autos is ok. Google NLGI grease.

>>>Metal "Shielded" BB's do not come apart. Don't even attempt it. There is a distinct difference between Rubber Sealed and metal shielded. Rubber seals Are removeable . Plain Metal Shields are Permanent. Shields do not Seal the BB. Always repace with Rubber sealed BB's. Shielded are best in Motors. Less friction to them, but are more exposed to dirt.
Just buy a set of Rubber Sealed BB's, to have on hand.
Best you can do with Shielded is spray flush them well, and oil them or spray a lube into them. Shielded BB's don't last as long. Except inside a motor, where they perform better and dirt ingress is much less. Only use Motor specific BB's when replacing them, if you do.

These 3 are my cars bestest friends.
Im Bad a maintaining bearings, I just keep buying fast Eddies by the hand-full, But I do keep the old ones and clean them; well I will at some point.
I find that if I oil as much of the car as I can each time its runs better and I rarely spin a bearing considering. Everything that moves!
I can see the few drops of oil sink into the bearing if you can get to it properly. Especially after you wash it. Soaks in past the seal easily enough I see. And although I try not to wash or soak the cars too often, sometimes you just have too! And that synthetic grease works great, just a little bit each time. It goes a long way. I use it in Diffs too. (That Blue Gel lock tight is good and forgiving BTW - for me regular red lock tight is bad unless you have a torch I guess.)

This is From what I learned and mostly from this forum.

Liberty Oil, Synthetic Oil for Lubricating R/C Radio Controlled Cars

Super Lube-21030 Synthetic Multi-Purpose Grease

 

[SrC]

CRC electrical spray is perfectly ok also. Just that it is much more expensive than Plain brake cleaner spray. I reserve the CRC for my Motor and its BB's only CRC is like double the price and more than plain Brake cleaner spray . At least here in the states.

Is that Center diff an alloy or plastic one?
If metal alloy, yes use some heat. Threadlocker is never used on screws with plastic parts.

 

[fish]

CRC electrical spray is perfectly ok also. Just that it is much more expensive than Plain brake cleaner spray. I reserve the CRC for my Motor and its BB's only CRC is like double the price and more than plain Brake cleaner spray . At least here in the states.

Is that Center diff an alloy or plastic one?
If metal alloy, yes use some heat. Threadlocker is never used on screws with plastic parts.

Yeah, thread lock only for metal to metal but I see people using 'Crazy Glue' for loose fitting metal screw to plastic. I haven't tried it.

and WHY is CRC electrical spray so expensive! No good reason .

 

[SrC]

CRC costs more because it is Safe on electrical motors and circuit Boards. Brake cleaner should ONLY be used on metal parts. And is always less $. Sometimes like $3.00 a can. CRC or Lectro-Motive sprayse, similar, is more than $10.00 a can and more
I use these oils and greases below,
for my RC's. For like 20+ years.
I use the Silicone grease for shock and Diff O-rings. I use a grease dispenser and a pinpoint oiler. I like Lucas Marine waterproof grease for my wet running Crawler BB's best. But Superlube also has some WP properties FWIW. And is thinner, for faster running BB's.

I find that threadlocker 243, works a bit better than 242. Maybe splitting hairs...just I've tried them all. Will hardly if ever use any Red TL'er. Been there.

 

[Ray87]

CRC electrical spray is perfectly ok also. Just that it is much more expensive than Plain brake cleaner spray. I reserve the CRC for my Motor and its BB's only CRC is like double the price and more than plain Brake cleaner spray . At least here in the states.

Is that Center diff an alloy or plastic one?
If metal alloy, yes use some heat. Threadlocker is never used on screws with plastic parts.

Yes will see what i find, brake cleaner when its cheaper, i have found 3 different greases but all of them is NLGI 2 and based on mineral oil, is this ok for the use or should i keep looking? After a Google search NLGI 2 seems ticker,

 

[SrC]

If it says NLGI anything, 1 or 2, you are golden. It is more than enough protection for our RC use.
From there, you decide what you think is working for you. Most all grease is mineral oil, lithium or petroleum based. For RC use doesn't matter. For Autos, there may be certain specs the Mfr desires. Synthetics cost slightly more, and seem to last longer IMHO. Your call.

 

[Ray87]

If it says NLGI anything, 1 or 2, you are golden. It is more than enough protection for our RC use.
From there, you decide what you think is working for you. Most all grease is mineral oil, lithium or petroleum based. For RC use doesn't matter. For Autos, there may be certain specs the Mfr desires. Synthetics cost slightly more, and seem to last longer IMHO. Your call.

Then i just go with the one i found on my local store with NLGI 2, always feels good when everything have the right type of greases/diff oil and it’s just ready to be used.

Earlier owner had probably used 1-2 mill center diff oil and i added 20mill for more air control, once i have this appart should i add grease on the outer center diff gears as well?

I had to heat the screws on center diff and when i finally opened it up i see that i have to get the other 4 screw out on the other side if i need to change bearing later?
Think this would be my last questions and i wont bother you more with this truck at least, thank you for been sutch a good help

 

[SrC]

Thank you for good help! And saving me the trouble for trying to open them.

One of them is a bit hard to spin so i will try to spray them from outside and clean it, do you recomend me to use a crc electric motor cleaner spray or should i just buy automobile brake cleaner?

Think i just order a pack from jimsbearings, it would cost me 2x price with tax paper plus 25% but it would be worth it and still cheap, cant even find the diff bearing here at all, i can find is same size from hpi but they are sold out, do you know if jimsbearings have same quality as the stock? Only 11 dollar for two arrma bearings or you can pay 35 dollar for every single bearings from Jim.

Another question for you, i just opened the center diff but two of the screws is stuckt because of this soaking loctite issue from factory. Could i use a storm lighter to heat them up? For about how long is enough to heat them? Should the flame be directly on the screw head or on the diffcase? Just affraid they can be too heated and becoming weak. don't want to wait 2-4 weeks on a new diff case if it goes south….

If when cleaning out that one or more BB's that won't spin freely anymore..... Whether it has too much radial play/slop to it or just remains seized/locked up, Do Not reuse it. It is toast. Toss it. And replace it. Having spare BB's on hand is a must with this hobby.

 

[Diem Turner]

>>>Metal "Shielded" BB's do not come apart. Don't even attempt it. There is a distinct difference between Rubber Sealed and metal shielded. Rubber seals Are removeable . Plain Metal Shields are Permanent. Shields do not Seal the BB. Always repace with Rubber sealed BB's. Shielded are best in Motors. Less friction to them, but are more exposed to dirt.

Not to nitpick (but you know I will), this is only partially true. There are two different kinds of metal shielded bearings.

First off, there are the economy type bearings that have press fit metal shields, easily identifiable by the slots every few mm that go all the way around the outside edge of the shield. These are designed to not be removed, though they can be extracted if one is so inclined. It's a bit of a faff but I've done it on numerous bearings. It's not worth the effort if you're running off-road, dirt, etc. as running open bearings under those conditions isn't the pro move. For speed running it's do-able, you just have to service them more frequently (I only do this if I don't have a better option available). The way I see it, I'd rather run open bearings that I can clean properly than closed bearings that I can't. But, as stated, whether or not this is a workable option will depend on what conditions you run your vehicle in.

And then you have the metal shielded bearings where the shield is made to be removable so they can be cleaned much more thoroughly than the above type. These are by far my favorite bearings and #1 choice if available. They have a thin c-clip that ride in a groove and can easily be removed with a needle or good set of very pointy tweezers. With regular maintenance these bearings last many times longer, easily justifying their price premium.

 

[SrC]

I have dealt with removing both types above. The press fit ones rarely if ever can be reassemble properly. They simply distort once removed, and end up hitting the cage as it rotates.
Circlip types are kind of rare. Usually costing more. More frequently found in BLX Motors.
These metal shielded type BB's do provide the best performance, least amount of friction. Rubber seals create some degree of rotating friction. But for Bashing use are just fine and more beneficial. The tighter seal at the Inner and Outer races do prevent dirt ingress. There is a trade off with both types.
I sometimes leave just one Rubber seal off and make sure that side is faced away from any potential dirt ingress. Facing inside a hub for example. The BB will have 50% less potential friction. Perhaps splitting hairs for most applications. I find that the better designed BB will always have a Plastic/Polymer type Cage. I found that metal type BB Cages explode/blow out much easier as the BB wears out.