New to RC - Maintenance

[MrGlad8]

Hello ! I just got my self a Arrma Granite 4x4 (Mega?) and I love it.

But I have some questions about the maintenance that I hope you can help me with.

Yesterday I got my two diffs removed. They were spinning really slow so I though there was some dirt inside. No matter what I did the there was some scratching when I was turning the big wheel. What could have happened? And both outside the diff and inside there was some kind of white/yellow grease but what I understand I should use silicone-oil at the diffs? Should I remove the grease and use silicone-oil instead?

And also, what kind of silicone-oil (cSt) should I use for my shocks? And also if I'm suppose to have oil on/in my diffs what kind of cSt should I use there?

Thank you!

 

[D3MON]

i usually use grease for my diffs, i don't recall if the granite has gasket sealed diffs or not. everyone has their own preference, mine still has the factory in it so i cant say what would be best diff grease after rebuild.
you will want to get shock oil for the shocks, it is relatively inexpensive and lasts awhile, i was recommended 50wt from my LHS.
https://www.towerhobbies.com/cgi-bi...Cc3flnc2Q-QpcnN0Lq2fzfeNv9vXEGuQaAv5AEALw_wcB

 

[GMballistic]

And both outside the diff and inside there was some kind of white/yellow grease but what I understand I should use silicone-oil at the diffs? Should I remove the grease and use silicone-oil instead?

I'm not overly familiar with the Granite but regardless it should be grease on the diffs ring gear on the outside and then silicone oil on the inside of the diff.

 

[D3MON]

I'm not overly familiar with the Granite but regardless it should be grease on the diffs ring gear on the outside and then silicone oil on the inside of the diff.

whoops! yup what he said, wasnt thinking about inside the diff!

 

[MrGlad8]

Thank you both for replies! When we say inside the diff we mean inside that cylinder-thing, right? And outside its basically on the big gear? I carefylly opened the cylinder but when I saw it was a lot of small gears I closed it for later. But it looked like it was grease inside the gear, is that bad then?

Ok, and what I understand people use diffrent diff-oil for back and rear diff? what the point of that? don't you want gear to spinn as fast and quick as possible?

And also, the shock-oil have diffrent "WT" right? Some said I should use WT30 .. is that just how easily the shocks damper the car?

Thank you!

 

[D3MON]

Thank you both for replies! When we say inside the diff we mean inside that cylinder-thing, right? And outside its basically on the big gear? I carefylly opened the cylinder but when I saw it was a lot of small gears I closed it for later. But it looked like it was grease inside the gear, is that bad then?

Ok, and what I understand people use diffrent diff-oil for back and rear diff? what the point of that? don't you want gear to spinn as fast and quick as possible?

And also, the shock-oil have diffrent "WT" right? Some said I should use WT30 .. is that just how easily the shocks damper the car?

Thank you!

inside the diffs some prefer it to be thicker, thicker oil will make it so left and right wheels will want to turn together more than not and ligher will make it easier for one to rotate instead of the other "unload", higher grip you want a bit lighter oil as your tires are going to be less prone to spinning out, looser grip areas you are going to want higher wt oil so if one tire spins the other one will still be trying to spin, and wont unload all the power to the spinning wheel.

it is common for it to be grease inside the diffs, typically RTR's are greased internals, but it is a common upgrade to fill with diff oil for tune-ability, and efficiency in both the rotation and lubrication factor.

inside the shocks on top of the shock push rod/shock shaft, is a little disc with small holes drilled into it to restrict the shock oil from moving completely freely, this gives the shocks the dampening effect. the higher weight in oil the thicker it is, which makes it flow through the holes slower adding higher dampening.
you are correct that the shock oils have higher "WT" to designate how "thick" it is.
factory oil weight somewhere around 30WT in these or so i was told by my LHS. and is a pretty common RTR Oil weight. typically for better control though a bit higher weight oil is desired for better control, some peoples driving styles this is not the case though.
id recomend getting a few different weight oils and experiment whats best for you.

Sorry was a little long winded XD

 

[MrGlad8]

inside the diffs some prefer it to be thicker, thicker oil will make it so left and right wheels will want to turn together more than not and ligher will make it easier for one to rotate instead of the other "unload", higher grip you want a bit lighter oil as your tires are going to be less prone to spinning out, looser grip areas you are going to want higher wt oil so if one tire spins the other one will still be trying to spin, and wont unload all the power to the spinning wheel.

it is common for it to be grease inside the diffs, typically RTR's are greased internals, but it is a common upgrade to fill with diff oil for tune-ability, and efficiency in both the rotation and lubrication factor.

inside the shocks on top of the shock push rod/shock shaft, is a little disc with small holes drilled into it to restrict the shock oil from moving completely freely, this gives the shocks the dampening effect. the higher weight in oil the thicker it is, which makes it flow through the holes slower adding higher dampening.
you are correct that the shock oils have higher "WT" to designate how "thick" it is.
factory oil weight somewhere around 30WT in these or so i was told by my LHS. and is a pretty common RTR Oil weight. typically for better control though a bit higher weight oil is desired for better control, some peoples driving styles this is not the case though.
id recomend getting a few different weight oils and experiment whats best for you.

Sorry was a little long winded XD

inside the diffs some prefer it to be thicker, thicker oil will make it so left and right wheels will want to turn together more than not and ligher will make it easier for one to rotate instead of the other "unload", higher grip you want a bit lighter oil as your tires are going to be less prone to spinning out, looser grip areas you are going to want higher wt oil so if one tire spins the other one will still be trying to spin, and wont unload all the power to the spinning wheel.

it is common for it to be grease inside the diffs, typically RTR's are greased internals, but it is a common upgrade to fill with diff oil for tune-ability, and efficiency in both the rotation and lubrication factor.

inside the shocks on top of the shock push rod/shock shaft, is a little disc with small holes drilled into it to restrict the shock oil from moving completely freely, this gives the shocks the dampening effect. the higher weight in oil the thicker it is, which makes it flow through the holes slower adding higher dampening.
you are correct that the shock oils have higher "WT" to designate how "thick" it is.
factory oil weight somewhere around 30WT in these or so i was told by my LHS. and is a pretty common RTR Oil weight. typically for better control though a bit higher weight oil is desired for better control, some peoples driving styles this is not the case though.
id recomend getting a few different weight oils and experiment whats best for you.

Sorry was a little long winded XD

Thank you for the very detailed answer, I need that
Ok so now I understand how its suppose to work, thats great!

But I'm still little unclear about the "WT" or "cSt" .. is that same thing diffrent unit?
Some said I should have silicon-oil 7000 on my read diff and 10000 on my front diff. Do they then mean that in "cSt" ?
And what do you use inside your diff? Does it really matter for me who only drive for fun and as an amateur? Can I leave it be grease inside the diff or will I as an amateur really notice any diffrence if I change it into a silicon-oil?
How do you fill it? Do you fill the diff up to the edge and then close the diff or what?

Thank you again

 

[D3MON]

Thank you for the very detailed answer, I need that
Ok so now I understand how its suppose to work, thats great!

But I'm still little unclear about the "WT" or "cSt" .. is that same thing diffrent unit?
Some said I should have silicon-oil 7000 on my read diff and 10000 on my front diff. Do they then mean that in "cSt" ?
And what do you use inside your diff? Does it really matter for me who only drive for fun and as an amateur? Can I leave it be grease inside the diff or will I as an amateur really notice any diffrence if I change it into a silicon-oil?
How do you fill it? Do you fill the diff up to the edge and then close the diff or what?

Thank you again

WT and CST are different but the same but different, they are both scales that differentiate oil thickness, but WT is isnt really a standard, its more or less each companies own measurement, wich happens to be close to everyone else's. WT measurement is non linear compared to CST (this is a standardized measurement i.e. think of it as a kilometer, that length is defined, whereas WT would be a few people saying "way over there". typically the diff fluids are advertised by their "WT" so unless the poster says "CST" its going to be weight.
also brands typically put the CST measurement in smaller lettering beneath their weight.

typically you do not fill it to the top, you want to fill it about 80% so as it warms up it doesn't over expand and try to push through gaskets and leak, or so im told.

as of yet i only have about 5-7 batteries give or take on the granite, and don't at this time feel that i need a rebuild.
on my Nitros though on my basher i use grease:
https://www.amazon.com/Napa-7651346...ocphy=9021355&hvtargid=pla-570724901273&psc=1
the other has oil in it, that truck has yet to be broken in yet, been too cold for me to deem it safe to break it in correctly.

 

[MrGlad8]

WT and CST are different but the same but different, they are both scales that differentiate oil thickness, but WT is isnt really a standard, its more or less each companies own measurement, wich happens to be close to everyone else's. WT measurement is non linear compared to CST (this is a standardized measurement i.e. think of it as a kilometer, that length is defined, whereas WT would be a few people saying "way over there". typically the diff fluids are advertised by their "WT" so unless the poster says "CST" its going to be weight.
also brands typically put the CST measurement in smaller lettering beneath their weight.

typically you do not fill it to the top, you want to fill it about 80% so as it warms up it doesn't over expand and try to push through gaskets and leak, or so im told.

as of yet i only have about 5-7 batteries give or take on the granite, and don't at this time feel that i need a rebuild.
on my Nitros though on my basher i use grease:
https://www.amazon.com/Napa-7651346...ocphy=9021355&hvtargid=pla-570724901273&psc=1
the other has oil in it, that truck has yet to be broken in yet, been too cold for me to deem it safe to break it in correctly.

Ok! Now I know a lot more about this. Thank you!

 

[MrGlad8]

Oh, I saw that the Arrma 4x4 Granite Mega had been discontinued, how come? What would you say is the next step if I want to buy another 4x4 in the future? I really like the 4x4 granite mega!

 

[D3MON]

Oh, I saw that the Arrma 4x4 Granite Mega had been discontinued, how come? What would you say is the next step if I want to buy another 4x4 in the future? I really like the 4x4 granite mega!

Did they discontinue the granite blx model as well?

 

[slick2500]

They discontinued the Mega 4x4 already?
Are you sure you aren't thinking of the 2wd, those have been discontinued.

 

[MrGlad8]

Hm, when I went into the mega 4x4 on their site to watch the exploaded view I saw the discontinue-label. And the site I ordered my car doesn't have it in stock anymore. Maybe its just the non brushless they removed?

 

[slick2500]

Hm, when I went into the mega 4x4 on their site to watch the exploaded view I saw the discontinue-label. And the site I ordered my car doesn't have it in stock anymore. Maybe its just the non brushless they removed?

Hmm weird shows as available for me. I knew they were out of stock/backordered everywhere there for a bit.

 

[Lazy Bushman]

@WoodiE has posted a few times a chart that shows the general driving characteristics associated with different weight fluids. This one relates to diffs:

https://www.arrmaforum.com/threads/differential-oil-weight-tips.1727/

And this to suspension:

https://www.arrmaforum.com/threads/shock-oil-wt-to-cst-conversion-chart.1454/

 

[MrGlad8]

@WoodiE has posted a few times a chart that shows the general driving characteristics associated with different weight fluids. This one relates to diffs:

https://www.arrmaforum.com/threads/differential-oil-weight-tips.1727/

And this to suspension:

https://www.arrmaforum.com/threads/shock-oil-wt-to-cst-conversion-chart.1454/

Great! Thank you!

 

[MrGlad8]

Hmm weird shows as available for me. I knew they were out of stock/backordered everywhere there for a bit.
View attachment 33141

Hm yes seems like false alarm then