I need an assortment of diff fluids and was wondering if anyone tried anything but the expensive silicone oils? Could i use automotive gear oil or even motor oil anything but spending 20 bucks for a few little tiney bottles of stuff?

Never tryed it but i wouldn't think so. I think the main thing with the silicone is it doesn't change viscosity in diferent weather conditions and temprature changes due to the cars heat, also you would have to find a way to mix some other fluid so that its the proper thickness. My suggestion is either start with the common 5000 front 7000 center 2000 rear set up or go to your local track and find out what the fast guys are running, then you only need three bottles of fluid. You can also mix the diff fluids to come up with other weights but seems like a pain to me.

okay now i understand why silicone is used and it makes sense. I live in rual arizona there is a hobby shop about an hours drive away and the only thing he carry's is the fuel and small things for electrics, i just dont really want to wait for it to ship here, im sure someone has tried it and maybe got ok results.

ive tryed using some normall mutigrade oil, parifine and grease to make differant thickness oil for my diffs. it worked pretty well but difficult to get it right and as mkincy said it's thickness changes aswell. it doesnt do any damage to your diffs , so give it a try if you like.

okay i did some thinking about it and please correct me if i am wrong, motor oil viscosity rating is based on the two numbers like 15-

40 and what not, the lowest number showing the viscosity when the oil is warm and 40 when the oil is cold seriously i cant even

remember completely. Newer cars engines run anywhere around 190 degree's and up and i seriously doubt the temperature inside a

1/8th scale

buggys differential could get above 120 if even that, so really i could just buy a variety of quart bottles of different viscosity going by

the highest viscosity number right?

Another thought- maybe use as shock oil as well

WHy not just order the diff oil off the internet?

if you had ordered the lubes off the internet the day you posted this, you would have them by now

i am going to order some off towers but what if there really isnt a need to buy it off the internet when it could be redily available at a auto parts store

Order it from www.amainhobbies.com, will probably have it the next day. Use mugen or ofna.

The problem with the motor oil is exactly what you mentioned. It changes viscosity with the temperature. Diff oil is made to stay consistantly the same. If you used motor oil your car would constently change handling as the car got hotter and cooler. Also shock oil would work, but it is too thin too do much. Also you could just use diff grease in them if your not racing, and handling isn't much issue.

There is a need since auto parts store don`t sell silicone oils .

It's not........ unless you buy all kinds of oils and research the properties of all of them..... whatever the point of that is.

The main problem is what the companies charge for the stuff! Waitng is bad enough but holy hell the price is enough to make Exxon blush!

Where are you guys buying diff oil . It`s only $8-9 a bottle and lasts a long time . So say $35 shipped for three bottles . If that breaks your piggy bank you might want to think of a different hobby .

[quote]ORIGINAL: Dawman


Where are you guys buying diff oil . It`s only $8-9 a bottle and lasts a long time . So say $35 shipped for three bottles . If that breaks your piggy bank you might want to think of a different hobby .
[/quote

Its not that i cant afford it.... its the fact that you gotta pay 35 bucks to get three tiney little bottles of the stuff, if they were bigger i could see the sense.... i know motor oil changes viscosity depending on the temperature but those are temperatures inside a cars engine and i cant say i know how hot the inside of a buggys diff gets im just assuming its alot less than a cars engine, maybe engine oil isnt right but that doesnt mean there isnt another product that will work readily available for alot cheaper.

heavy duty gear oil will work, but u cant vary viscosity much. also, bar and chain oil for chain saws is about right, but again, cant vary it.

the problem is finding the right viscosity, and motor oil wont work well.

Well i just found where to buy silicone oil in bulk, dow corning the company that you see on those tubes of rtv and stuff.... they make a MASSIVE variety of every silicone substance you can think of, the units are sold by the gallon for 35, a five gallon bucket for 165 or a 55 gallon drum for 1000 something.

i am first going to buy the gallon can of a thicker oil to be the base, then just take small bottles and dilude them to a thinner viscosity and try it out maybe it will work. at the same time i am ordering some oil from tower hobbies to compare.

the only thing i am completely stumped on is how in the hell does a person measure viscosity of a fluid....

the silicone oil everyone uses will blend with other silicone oil right? i think i read that somewhere

The "tiny " bottles last a long time since the diffs don`t use a lot . So it goes a long way , good luck with your experiment .

By the way do not order from a-main hobbies if you are in a hurry.....very slow shipper. Try tower they will ship out the same day.

It's actually pretty simple. You measure the time it takes for a specific volume of fluid to flow through a funnel with a (to me unknown) hole.
Do a google search of viscosity and you'll see alot of info.

i did the google search and found out i need to build a "viscometer". I think i know how to build one that will work fine, what kind of fluid does everyone use? what weights does everyone use?

A good starting point is 5000 , 7000 , and 3000 . But it can differ on your buggy , track conditions , and driving style .

Umm, I think the fluid you use is the fluid you are going to measure. I'm not sure what fluid you mean.

[link=http://www.hanssummers.com/electronics/viscometer/index.htm]Here is an awesome project of a different type of viscometer.[/link]

It almost makes we want to build one.
Before I do that I have to build an engine dyno. LOL and that's far far away in the futire...... maybe.

the most common is 5000 front 7000 center and 2000 rear, but depends on the track conditions.